How do you convert a DataTable into a generic list

Question

Currently  I m using   DataTable dt   CreateDataTableInSomeWay     List lt DataRow gt  list   new List lt DataRow gt      foreach  DataRow dr in dt Rows        list Add dr       Is there a better magic way

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Again  using 3 5 you may do it like   dt Select   ToList     BRGDS

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using System Data    var myEnumerable   myDataTable AsEnumerable     List lt MyClass gt  myClassList        from item in myEnumerable      select new MyClass           MyClassProperty1   item Field lt string gt   DataTableColumnName1             MyClassProperty2   item Field lt string gt   DataTableColumnName2          ToList

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This worked for me   Need at least  Net Framework 3 5  Code below displays DataRow turned to Generic IEnumerable  comboBox1 has been used for a better illustration    using System Linq   DataTable dt   new DataTable                dt   myClass myMethod                     List lt object gt  list    from row in dt AsEnumerable   select  row  name     ToList    comboBox1 DataSource   list

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If anyone want s to create custom function to convert datatable to list class Program       static void Main string   args                DataTable table   GetDataTable            var sw   new Stopwatch             sw Start            LinqMethod table           sw Stop            Console WriteLine  quot Elapsed time for Linq Method  0  quot   sw ElapsedMilliseconds            sw Reset             sw Start            ForEachMethod table           sw Stop            Console WriteLine  quot Elapsed time for Foreach method  0  quot   sw ElapsedMilliseconds            Console ReadKey               private static DataTable GetDataTable                 var table   new DataTable            table Columns Add  quot ID quot   typeof double            table Columns Add  quot CategoryName quot   typeof string            table Columns Add  quot Active quot   typeof double             var rand   new Random             for  int i   0  i  lt  100000  i                          table Rows Add i   quot name quot    i   rand Next 0  2                      return table             private static void LinqMethod DataTable table                var list   table AsEnumerable                Skip 1               Select dr   gt                  new Category                                       Id   Convert ToInt32 dr Field lt double gt   quot ID quot                         CategoryName   dr Field lt string gt   quot CategoryName quot                                              IsActive                               dr Field lt double gt   quot Active quot      1   true   false                    ToList              private static void ForEachMethod DataTable table                var categoryList   new List lt Category gt  table Rows Count           foreach  DataRow row in table Rows                        var values   row ItemArray              var category   new Category                                 Id   Convert ToInt32 values 0                    CategoryName   Convert ToString values 1                                       IsActive    double values 2     1   true   false                            categoryList Add category                        private class Category               public int Id   get  set            public string CategoryName   get  set            public bool IsActive   get  set             If we execute above code  Foreach method finishes in 56ms while linq one takes 101ms   for 1000 records   So Foreach method is better to use  Source Ways to Convert Datatable to List in C   with performance test example

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This is a generic method that will convert any type of DataTable to a List                                     Example      List lt  Student  gt  studentDetails   new List lt  Student  gt                               studentDetails   ConvertDataTable lt  Student  gt  dt                           Warning   In this case the DataTable column s name and class property name                      should be the same otherwise this function will not work properly                  The following are the two functions in which if we pass a   DataTable                 and a user defined class                  It will then return the List of that class with the DataTable data            public static List lt T gt  ConvertDataTable lt T gt  DataTable dt                        List lt T gt  data   new List lt T gt                 foreach  DataRow row in dt Rows                                T item   GetItem lt T gt  row                   data Add item                             return data                      private static T GetItem lt T gt  DataRow dr                        Type temp   typeof T               T obj   Activator CreateInstance lt T gt                  foreach  DataColumn column in dr Table Columns                                foreach  PropertyInfo pro in temp GetProperties                                           in case you have a enum GUID datatype in your model                      We will check field s dataType  and convert the value in it                      if  pro Name    column ColumnName                                       try                                               var convertedValue   GetValueByDataType pro PropertyType  dr column ColumnName                            pro SetValue obj  convertedValue  null                                             catch  Exception e                                                          ex handle code                                            throw                                                  pro SetValue obj  dr column ColumnName   null                                         else                         continue                                              return obj                 This method will check the datatype of field  and convert dataTable value in to that datatype        private static object GetValueByDataType Type propertyType  object o                if  o ToString       null                         return null                    if  propertyType     typeof Guid      propertyType    typeof Guid                          return Guid Parse o ToString                       else if  propertyType    typeof int     propertyType IsEnum                         return Convert ToInt32 o                     else if  propertyType    typeof decimal                          return Convert ToDecimal o                     else if  propertyType    typeof long                         return Convert ToInt64 o                     else if  propertyType    typeof bool     propertyType    typeof bool                          return Convert ToBoolean o                     else if  propertyType    typeof DateTime     propertyType    typeof DateTime                          return Convert ToDateTime o                     return o ToString               To call the preceding method  use the following syntax    List lt  Student  gt  studentDetails   new List lt  Student  gt       studentDetails   ConvertDataTable lt  Student  gt  dt         Change the Student class name and dt value based on your requirements  In this case the DataTable column s name and class property name should be the same otherwise this function will not work properly

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You could use   List lt DataRow gt  list   new List lt DataRow gt  dt Select       dt Select   will return all rows in your table  as an array of datarows  and the List constructor accepts that array of objects as an argument to initially fill your list with

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lPerson   dt AsEnumerable   Select s   gt  new Person                         Name   s Field lt string gt   Name                SurName   s Field lt string gt   SurName                Age   s Field lt int gt   Age                InsertDate   s Field lt DateTime gt   InsertDate              ToList      Link to working DotNetFiddle Example  using System  using System Collections Generic     using System Data  using System Linq  using System Data DataSetExtensions   public static void Main         DataTable dt   new DataTable        dt Columns Add  Name   typeof string        dt Columns Add  SurName   typeof string        dt Columns Add  Age   typeof int        dt Columns Add  InsertDate   typeof DateTime         var row1  dt NewRow        row1  Name      Adam       row1  SurName      Adam       row1  Age     20      row1  InsertDate     new DateTime 2020  1  1       dt Rows Add row1        var row2   dt NewRow        row2  Name      John       row2  SurName      Smith       row2  Age     25      row2  InsertDate     new DateTime 2020  3  12       dt Rows Add row2        var row3   dt NewRow        row3  Name      Jack       row3  SurName      Strong       row3  Age     32      row3  InsertDate     new DateTime 2020  5  20       dt Rows Add row3        List lt Person gt  lPerson   new List lt Person gt         lPerson   dt AsEnumerable   Select s   gt  new Person                 Name   s Field lt string gt   Name            SurName   s Field lt string gt   SurName            Age   s Field lt int gt   Age            InsertDate   s Field lt DateTime gt   InsertDate          ToList         foreach Person pers in lPerson                Console WriteLine   0   1   2   3    pers Name  pers SurName  pers Age  pers InsertDate               public class Person       public string Name   get  set        public string SurName   get  set        public int Age   get  set        public DateTime InsertDate   get  set

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lPerson   dt AsEnumerable   Select s   gt  new Person                         Name   s Field lt string gt   Name                SurName   s Field lt string gt   SurName                Age   s Field lt int gt   Age                InsertDate   s Field lt DateTime gt   InsertDate              ToList      Link to working DotNetFiddle Example  using System  using System Collections Generic     using System Data  using System Linq  using System Data DataSetExtensions   public static void Main         DataTable dt   new DataTable        dt Columns Add  Name   typeof string        dt Columns Add  SurName   typeof string        dt Columns Add  Age   typeof int        dt Columns Add  InsertDate   typeof DateTime         var row1  dt NewRow        row1  Name      Adam       row1  SurName      Adam       row1  Age     20      row1  InsertDate     new DateTime 2020  1  1       dt Rows Add row1        var row2   dt NewRow        row2  Name      John       row2  SurName      Smith       row2  Age     25      row2  InsertDate     new DateTime 2020  3  12       dt Rows Add row2        var row3   dt NewRow        row3  Name      Jack       row3  SurName      Strong       row3  Age     32      row3  InsertDate     new DateTime 2020  5  20       dt Rows Add row3        List lt Person gt  lPerson   new List lt Person gt         lPerson   dt AsEnumerable   Select s   gt  new Person                 Name   s Field lt string gt   Name            SurName   s Field lt string gt   SurName            Age   s Field lt int gt   Age            InsertDate   s Field lt DateTime gt   InsertDate          ToList         foreach Person pers in lPerson                Console WriteLine   0   1   2   3    pers Name  pers SurName  pers Age  pers InsertDate               public class Person       public string Name   get  set        public string SurName   get  set        public int Age   get  set        public DateTime InsertDate   get  set

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Use Extension    public static class Extensions        region Convert Datatable To List     public static IList lt T gt  ToList lt T gt  this DataTable table  where T   new                 IList lt PropertyInfo gt  properties   typeof T  GetProperties   ToList            IList lt T gt  result   new List lt T gt              foreach  var row in table Rows                        var item   CreateItemFromRow lt T gt   DataRow row  properties               result Add item                     return result            private static T CreateItemFromRow lt T gt  DataRow row  IList lt PropertyInfo gt  properties  where T   new                 T item   new T            foreach  var property in properties                        property SetValue item  row property Name   null                     return item             endregion

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Here s a DataTable extension method that converts a DataTable to a generic list   https   gist github com gaui a0a615029f1327296cf8  Usage   List lt Employee gt  emp   dtTable DataTableToList lt Employee gt

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You could use   List lt DataRow gt  list   new List lt DataRow gt  dt Select       dt Select   will return all rows in your table  as an array of datarows  and the List constructor accepts that array of objects as an argument to initially fill your list with

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this is better suited for expensive object creation initialization IEnumerable lt Employee gt  ParseEmployeeTable DataTable dtEmployees        var employees   new ConcurrentBag lt Employee gt          Parallel ForEach dtEmployees AsEnumerable     dr    gt                employees Add new Employee                           FirstName   dr  FirstName   ToString                 LastName   dr  Last Name   ToString                            return employees

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If you just want a list of values from the  ID  int field returned  you could use     List lt int gt  ids    from row in dt AsEnumerable   select Convert ToInt32 row  ID     ToList

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I have added some modification to the code from this answer  https   stackoverflow com a 24588210 4489664  because for nullable Types it will return exception   public static List lt T gt  DataTableToList lt T gt  this DataTable table  where T  new         List lt T gt  list   new List lt T gt         var typeProperties   typeof T  GetProperties   Select propertyInfo   gt  new                       PropertyInfo   propertyInfo              Type   Nullable GetUnderlyingType propertyInfo PropertyType     propertyInfo PropertyType            ToList         foreach  var row in table Rows Cast lt DataRow gt                   T obj   new T            foreach  var typeProperty in typeProperties                        object value   row typeProperty PropertyInfo Name               object safeValue   value    null    DBNull Value Equals value                    null                   Convert ChangeType value  typeProperty Type                typeProperty PropertyInfo SetValue obj  safeValue  null                     list Add obj             return list

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If you re using  NET 3 5  you can use DataTableExtensions AsEnumerable  an extension method  and then if you really need a List lt DataRow gt  instead of just IEnumerable lt DataRow gt  you can call Enumerable ToList   IEnumerable lt DataRow gt  sequence   dt AsEnumerable      or  using System Linq      List lt DataRow gt  list   dt AsEnumerable   ToList

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To assign the DataTable rows to the generic List of class    List lt Candidate gt  temp   new List lt Candidate gt      List that holds the Candidate Class        Note The Candidate class contains RollNo Name and Department       tb is DataTable     temp    from DataRow dr in tb Rows                         select new Candidate                                                         RollNO   Convert ToInt32 dr  RollNO                                 Name   dr  Name   ToString                                Department   dr  Department   ToString                                ToList

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List lt Employee gt  emp   new List lt Employee gt        Maintaining DataTable on ViewState   For Demo only  DataTable dt   ViewState  CurrentEmp   as DataTable     read data from DataTable    using lamdaexpression   emp    from DataRow row in dt Rows     select new Employee              FirstName   row  FirstName   ToString            LastName   row  Last Name   ToString          ToList

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The Easiest way of Converting the DataTable into the Generic list of class  using Newtonsoft Json   var json   JsonConvert SerializeObject dataTable   var model   JsonConvert DeserializeObject lt List lt ClassName gt  gt  json

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You can use a generic method like that for datatable to generic list   public static List lt T gt  DataTableToList lt T gt  this DataTable table  where T   class  new         try               List lt T gt  list   new List lt T gt              foreach  var row in table AsEnumerable                          T obj   new T                 foreach  var prop in obj GetType   GetProperties                                  try                                       PropertyInfo propertyInfo   obj GetType   GetProperty prop Name                       if  propertyInfo PropertyType IsEnum                                                propertyInfo SetValue obj  Enum Parse propertyInfo PropertyType  row prop Name  ToString                                                else                                               propertyInfo SetValue obj  Convert ChangeType row prop Name   propertyInfo PropertyType   null                                                                                     catch                                       continue                                               list Add obj                      return list            catch               return null

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Here s a DataTable extension method that converts a DataTable to a generic list   https   gist github com gaui a0a615029f1327296cf8  Usage   List lt Employee gt  emp   dtTable DataTableToList lt Employee gt

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DataTable dt       datatable should contains datacolumns with Id Name  List lt Employee gt  employeeList new List lt Employee gt         Employee should contain  EmployeeId  EmployeeName as properties  foreach  DataRow dr in dt Rows        employeeList Add new Employee EmployeeId dr Id EmplooyeeName dr Name

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DataTable Select   doesnt give the Rows in the order they were present in the datatable   If order is important I feel iterating over the datarow collection and forming a List is the right way to go or you could also use overload of DataTable Select string filterexpression  string sort    But this overload may not handle all the ordering  like order by case      that SQL provides

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This is a generic method that will convert any type of DataTable to a List                                     Example      List lt  Student  gt  studentDetails   new List lt  Student  gt                               studentDetails   ConvertDataTable lt  Student  gt  dt                           Warning   In this case the DataTable column s name and class property name                      should be the same otherwise this function will not work properly                  The following are the two functions in which if we pass a   DataTable                 and a user defined class                  It will then return the List of that class with the DataTable data            public static List lt T gt  ConvertDataTable lt T gt  DataTable dt                        List lt T gt  data   new List lt T gt                 foreach  DataRow row in dt Rows                                T item   GetItem lt T gt  row                   data Add item                             return data                      private static T GetItem lt T gt  DataRow dr                        Type temp   typeof T               T obj   Activator CreateInstance lt T gt                  foreach  DataColumn column in dr Table Columns                                foreach  PropertyInfo pro in temp GetProperties                                           in case you have a enum GUID datatype in your model                      We will check field s dataType  and convert the value in it                      if  pro Name    column ColumnName                                       try                                               var convertedValue   GetValueByDataType pro PropertyType  dr column ColumnName                            pro SetValue obj  convertedValue  null                                             catch  Exception e                                                          ex handle code                                            throw                                                  pro SetValue obj  dr column ColumnName   null                                         else                         continue                                              return obj                 This method will check the datatype of field  and convert dataTable value in to that datatype        private static object GetValueByDataType Type propertyType  object o                if  o ToString       null                         return null                    if  propertyType     typeof Guid      propertyType    typeof Guid                          return Guid Parse o ToString                       else if  propertyType    typeof int     propertyType IsEnum                         return Convert ToInt32 o                     else if  propertyType    typeof decimal                          return Convert ToDecimal o                     else if  propertyType    typeof long                         return Convert ToInt64 o                     else if  propertyType    typeof bool     propertyType    typeof bool                          return Convert ToBoolean o                     else if  propertyType    typeof DateTime     propertyType    typeof DateTime                          return Convert ToDateTime o                     return o ToString               To call the preceding method  use the following syntax    List lt  Student  gt  studentDetails   new List lt  Student  gt       studentDetails   ConvertDataTable lt  Student  gt  dt         Change the Student class name and dt value based on your requirements  In this case the DataTable column s name and class property name should be the same otherwise this function will not work properly

User · Answer

With C  3 0 and System Data DataSetExtensions dll   List lt DataRow gt  rows   table Rows Cast lt DataRow gt    ToList

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With C  3 0 and System Data DataSetExtensions dll   List lt DataRow gt  rows   table Rows Cast lt DataRow gt    ToList

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Use System Data namespace then you will get  AsEnumerable

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Output  public class ModelUser        region Model      private string  username      private string  userpassword      private string  useremail      private int  userid            lt summary gt                    lt  summary gt      public int userid               set    userid   value            get   return  userid                     lt summary gt                    lt  summary gt       public string username               set    username   value            get   return  username                    lt summary gt                    lt  summary gt      public string useremail               set    useremail   value            get   return  useremail                    lt summary gt                    lt  summary gt      public string userpassword               set    userpassword   value            get   return  userpassword               endregion Model    public List lt ModelUser gt  DataTableToList DataTable dt        List lt ModelUser gt  modelList   new List lt ModelUser gt         int rowsCount   dt Rows Count      if  rowsCount  gt  0                ModelUser model          for  int n   0  n  lt  rowsCount  n                          model   new ModelUser                 model userid    int dt Rows n   userid                model username   dt Rows n   username   ToString                model useremail   dt Rows n   useremail   ToString                model userpassword   dt Rows n   userpassword   ToString                 modelList Add model                       return modelList     static DataTable GetTable            Here we create a DataTable with four columns      DataTable table   new DataTable        table Columns Add  userid   typeof int        table Columns Add  username   typeof string        table Columns Add  useremail   typeof string        table Columns Add  userpassword   typeof string            Here we add five DataRows      table Rows Add 25   Jame    Jame hotmail com   DateTime Now ToString         table Rows Add 50   luci    luci hotmail com   DateTime Now ToString         table Rows Add 10   Andrey    Andrey hotmail com   DateTime Now ToString         table Rows Add 21   Michael    Michael hotmail com   DateTime Now ToString         table Rows Add 100   Steven    Steven hotmail com   DateTime Now ToString         return table     protected void Page Load object sender  EventArgs e        List lt ModelUser gt  userList   new List lt ModelUser gt          DataTable dt   GetTable         userList   DataTableToList dt        gv DataSource   userList      gv DataBind      enter image description here  1            lt  asp GridView gt   lt  div gt

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You could use   List lt DataRow gt  list   new List lt DataRow gt  dt Select       dt Select   will return all rows in your table  as an array of datarows  and the List constructor accepts that array of objects as an argument to initially fill your list with

User · Answer

If you just want a list of values from the  ID  int field returned  you could use     List lt int gt  ids    from row in dt AsEnumerable   select Convert ToInt32 row  ID     ToList

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Converting DataTable to Generic Dictionary   public static Dictionary lt object IList lt dynamic gt  gt  DataTable2Dictionary DataTable dt        Dictionary lt object  IList lt dynamic gt  gt  dict   new Dictionary lt dynamic  IList lt dynamic gt  gt          foreach DataColumn column in dt Columns                IList lt dynamic gt  ts   dt AsEnumerable                                  Select r   gt  r Field lt dynamic gt  column ToString                                    ToList            dict Add column  ts             return dict

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I have added some modification to the code from this answer  https   stackoverflow com a 24588210 4489664  because for nullable Types it will return exception   public static List lt T gt  DataTableToList lt T gt  this DataTable table  where T  new         List lt T gt  list   new List lt T gt         var typeProperties   typeof T  GetProperties   Select propertyInfo   gt  new                       PropertyInfo   propertyInfo              Type   Nullable GetUnderlyingType propertyInfo PropertyType     propertyInfo PropertyType            ToList         foreach  var row in table Rows Cast lt DataRow gt                   T obj   new T            foreach  var typeProperty in typeProperties                        object value   row typeProperty PropertyInfo Name               object safeValue   value    null    DBNull Value Equals value                    null                   Convert ChangeType value  typeProperty Type                typeProperty PropertyInfo SetValue obj  safeValue  null                     list Add obj             return list

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With C  3 0 and System Data DataSetExtensions dll   List lt DataRow gt  rows   table Rows Cast lt DataRow gt    ToList

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With C  3 0 and System Data DataSetExtensions dll   List lt DataRow gt  rows   table Rows Cast lt DataRow gt    ToList

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Output  public class ModelUser        region Model      private string  username      private string  userpassword      private string  useremail      private int  userid            lt summary gt                    lt  summary gt      public int userid               set    userid   value            get   return  userid                     lt summary gt                    lt  summary gt       public string username               set    username   value            get   return  username                    lt summary gt                    lt  summary gt      public string useremail               set    useremail   value            get   return  useremail                    lt summary gt                    lt  summary gt      public string userpassword               set    userpassword   value            get   return  userpassword               endregion Model    public List lt ModelUser gt  DataTableToList DataTable dt        List lt ModelUser gt  modelList   new List lt ModelUser gt         int rowsCount   dt Rows Count      if  rowsCount  gt  0                ModelUser model          for  int n   0  n  lt  rowsCount  n                          model   new ModelUser                 model userid    int dt Rows n   userid                model username   dt Rows n   username   ToString                model useremail   dt Rows n   useremail   ToString                model userpassword   dt Rows n   userpassword   ToString                 modelList Add model                       return modelList     static DataTable GetTable            Here we create a DataTable with four columns      DataTable table   new DataTable        table Columns Add  userid   typeof int        table Columns Add  username   typeof string        table Columns Add  useremail   typeof string        table Columns Add  userpassword   typeof string            Here we add five DataRows      table Rows Add 25   Jame    Jame hotmail com   DateTime Now ToString         table Rows Add 50   luci    luci hotmail com   DateTime Now ToString         table Rows Add 10   Andrey    Andrey hotmail com   DateTime Now ToString         table Rows Add 21   Michael    Michael hotmail com   DateTime Now ToString         table Rows Add 100   Steven    Steven hotmail com   DateTime Now ToString         return table     protected void Page Load object sender  EventArgs e        List lt ModelUser gt  userList   new List lt ModelUser gt          DataTable dt   GetTable         userList   DataTableToList dt        gv DataSource   userList      gv DataBind      enter image description here  1            lt  asp GridView gt   lt  div gt

User · Answer

Again  using 3 5 you may do it like   dt Select   ToList     BRGDS

User · Answer

If you re using  NET 3 5  you can use DataTableExtensions AsEnumerable  an extension method  and then if you really need a List lt DataRow gt  instead of just IEnumerable lt DataRow gt  you can call Enumerable ToList   IEnumerable lt DataRow gt  sequence   dt AsEnumerable      or  using System Linq      List lt DataRow gt  list   dt AsEnumerable   ToList

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This worked for me   Need at least  Net Framework 3 5  Code below displays DataRow turned to Generic IEnumerable  comboBox1 has been used for a better illustration    using System Linq   DataTable dt   new DataTable                dt   myClass myMethod                     List lt object gt  list    from row in dt AsEnumerable   select  row  name     ToList    comboBox1 DataSource   list

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DataTable Select   doesnt give the Rows in the order they were present in the datatable   If order is important I feel iterating over the datarow collection and forming a List is the right way to go or you could also use overload of DataTable Select string filterexpression  string sort    But this overload may not handle all the ordering  like order by case      that SQL provides

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Converting DataTable to Generic Dictionary   public static Dictionary lt object IList lt dynamic gt  gt  DataTable2Dictionary DataTable dt        Dictionary lt object  IList lt dynamic gt  gt  dict   new Dictionary lt dynamic  IList lt dynamic gt  gt          foreach DataColumn column in dt Columns                IList lt dynamic gt  ts   dt AsEnumerable                                  Select r   gt  r Field lt dynamic gt  column ToString                                    ToList            dict Add column  ts             return dict

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You can create a extension function as    public static List lt T gt  ToListof lt T gt  this DataTable dt        const BindingFlags flags   BindingFlags Public   BindingFlags Instance      var columnNames   dt Columns Cast lt DataColumn gt             Select c   gt  c ColumnName           ToList        var objectProperties   typeof T  GetProperties flags       var targetList   dt AsEnumerable   Select dataRow   gt                var instanceOfT   Activator CreateInstance lt T gt              foreach  var properties in objectProperties Where properties   gt  columnNames Contains properties Name   amp  amp  dataRow properties Name     DBNull Value                         properties SetValue instanceOfT  dataRow properties Name   null                     return instanceOfT         ToList         return targetList      var output   yourDataInstance ToListof lt targetModelType gt

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You could use   List lt DataRow gt  list   new List lt DataRow gt  dt Select       dt Select   will return all rows in your table  as an array of datarows  and the List constructor accepts that array of objects as an argument to initially fill your list with

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A more  magic  way  and doesn t need  NET 3 5   If  for example  DBDatatable was returning a single column of Guids  uniqueidentifier in SQL  then you could use   Dim gList As New List Of Guid  gList AddRange DirectCast DBDataTable Select    IEnumerable Of Guid

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We can use a Generic Method for converting DataTable to List instead of manually converting a DataTable to List   Note  DataTable s ColumnName and Type s PropertyName should be same   Call the below Method   long result   Utilities ConvertTo lt Student gt  dt  out listStudent       Generic Method public class Utilities       public static long ConvertTo lt T gt  DataTable table  out List lt T gt  entity                long returnCode   -1          entity   null           if  table    null                        return -1                     try                       entity   ConvertTo lt T gt  table Rows               returnCode   0                     catch  Exception ex                        returnCode   1000                     return returnCode             static List lt T gt  ConvertTo lt T gt  DataRowCollection rows                List lt T gt  list   null          if  rows    null                        list   new List lt T gt                  foreach  DataRow row in rows                                T item   CreateItem lt T gt  row                   list Add item                                    return list             static T CreateItem lt T gt  DataRow row                string str   string Empty          string strObj   string Empty           T obj   default T            if  row    null                        obj   Activator CreateInstance lt T gt                 strObj   obj ToString                NameValueCollection objDictionary   new NameValueCollection                 foreach  DataColumn column in row Table Columns                                PropertyInfo prop   obj GetType   GetProperty column ColumnName                    if  prop    null                                        str   column ColumnName                       try                                               objDictionary Add str  row str  ToString                             object value   row column ColumnName                           Type vType   obj GetType                             if  value    DBNull Value                                                        if  vType    typeof int     vType    typeof Int16                                                          vType    typeof Int32                                                          vType    typeof Int64                                                          vType    typeof decimal                                                          vType    typeof float                                                          vType    typeof double                                                                 value   0                                                             else if  vType    typeof bool                                                                 value   false                                                             else if  vType    typeof DateTime                                                                 value   DateTime MaxValue                                                             else                                                               value   null                                                             prop SetValue obj  value  null                                                      else                                                       prop SetValue obj  value  null                                                                        catch Exception ex                                                                                            PropertyInfo ActionProp   obj GetType   GetProperty  ActionTemplateValue                 if  ActionProp    null                                object ActionValue   objDictionary                  ActionProp SetValue obj  ActionValue  null                                    return obj

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DataTable dt       datatable should contains datacolumns with Id Name  List lt Employee gt  employeeList new List lt Employee gt         Employee should contain  EmployeeId  EmployeeName as properties  foreach  DataRow dr in dt Rows        employeeList Add new Employee EmployeeId dr Id EmplooyeeName dr Name

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You can create a extension function as    public static List lt T gt  ToListof lt T gt  this DataTable dt        const BindingFlags flags   BindingFlags Public   BindingFlags Instance      var columnNames   dt Columns Cast lt DataColumn gt             Select c   gt  c ColumnName           ToList        var objectProperties   typeof T  GetProperties flags       var targetList   dt AsEnumerable   Select dataRow   gt                var instanceOfT   Activator CreateInstance lt T gt              foreach  var properties in objectProperties Where properties   gt  columnNames Contains properties Name   amp  amp  dataRow properties Name     DBNull Value                         properties SetValue instanceOfT  dataRow properties Name   null                     return instanceOfT         ToList         return targetList      var output   yourDataInstance ToListof lt targetModelType gt

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We can use a Generic Method for converting DataTable to List instead of manually converting a DataTable to List   Note  DataTable s ColumnName and Type s PropertyName should be same   Call the below Method   long result   Utilities ConvertTo lt Student gt  dt  out listStudent       Generic Method public class Utilities       public static long ConvertTo lt T gt  DataTable table  out List lt T gt  entity                long returnCode   -1          entity   null           if  table    null                        return -1                     try                       entity   ConvertTo lt T gt  table Rows               returnCode   0                     catch  Exception ex                        returnCode   1000                     return returnCode             static List lt T gt  ConvertTo lt T gt  DataRowCollection rows                List lt T gt  list   null          if  rows    null                        list   new List lt T gt                  foreach  DataRow row in rows                                T item   CreateItem lt T gt  row                   list Add item                                    return list             static T CreateItem lt T gt  DataRow row                string str   string Empty          string strObj   string Empty           T obj   default T            if  row    null                        obj   Activator CreateInstance lt T gt                 strObj   obj ToString                NameValueCollection objDictionary   new NameValueCollection                 foreach  DataColumn column in row Table Columns                                PropertyInfo prop   obj GetType   GetProperty column ColumnName                    if  prop    null                                        str   column ColumnName                       try                                               objDictionary Add str  row str  ToString                             object value   row column ColumnName                           Type vType   obj GetType                             if  value    DBNull Value                                                        if  vType    typeof int     vType    typeof Int16                                                          vType    typeof Int32                                                          vType    typeof Int64                                                          vType    typeof decimal                                                          vType    typeof float                                                          vType    typeof double                                                                 value   0                                                             else if  vType    typeof bool                                                                 value   false                                                             else if  vType    typeof DateTime                                                                 value   DateTime MaxValue                                                             else                                                               value   null                                                             prop SetValue obj  value  null                                                      else                                                       prop SetValue obj  value  null                                                                        catch Exception ex                                                                                            PropertyInfo ActionProp   obj GetType   GetProperty  ActionTemplateValue                 if  ActionProp    null                                object ActionValue   objDictionary                  ActionProp SetValue obj  ActionValue  null                                    return obj

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using System Data    var myEnumerable   myDataTable AsEnumerable     List lt MyClass gt  myClassList        from item in myEnumerable      select new MyClass           MyClassProperty1   item Field lt string gt   DataTableColumnName1             MyClassProperty2   item Field lt string gt   DataTableColumnName2          ToList

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If you re using  NET 3 5  you can use DataTableExtensions AsEnumerable  an extension method  and then if you really need a List lt DataRow gt  instead of just IEnumerable lt DataRow gt  you can call Enumerable ToList   IEnumerable lt DataRow gt  sequence   dt AsEnumerable      or  using System Linq      List lt DataRow gt  list   dt AsEnumerable   ToList

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this is better suited for expensive object creation initialization IEnumerable lt Employee gt  ParseEmployeeTable DataTable dtEmployees        var employees   new ConcurrentBag lt Employee gt          Parallel ForEach dtEmployees AsEnumerable     dr    gt                employees Add new Employee                           FirstName   dr  FirstName   ToString                 LastName   dr  Last Name   ToString                            return employees

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You can use a generic method like that for datatable to generic list   public static List lt T gt  DataTableToList lt T gt  this DataTable table  where T   class  new         try               List lt T gt  list   new List lt T gt              foreach  var row in table AsEnumerable                          T obj   new T                 foreach  var prop in obj GetType   GetProperties                                  try                                       PropertyInfo propertyInfo   obj GetType   GetProperty prop Name                       if  propertyInfo PropertyType IsEnum                                                propertyInfo SetValue obj  Enum Parse propertyInfo PropertyType  row prop Name  ToString                                                else                                               propertyInfo SetValue obj  Convert ChangeType row prop Name   propertyInfo PropertyType   null                                                                                     catch                                       continue                                               list Add obj                      return list            catch               return null

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The Easiest way of Converting the DataTable into the Generic list of class  using Newtonsoft Json   var json   JsonConvert SerializeObject dataTable   var model   JsonConvert DeserializeObject lt List lt ClassName gt  gt  json

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Use Extension    public static class Extensions        region Convert Datatable To List     public static IList lt T gt  ToList lt T gt  this DataTable table  where T   new                 IList lt PropertyInfo gt  properties   typeof T  GetProperties   ToList            IList lt T gt  result   new List lt T gt              foreach  var row in table Rows                        var item   CreateItemFromRow lt T gt   DataRow row  properties               result Add item                     return result            private static T CreateItemFromRow lt T gt  DataRow row  IList lt PropertyInfo gt  properties  where T   new                 T item   new T            foreach  var property in properties                        property SetValue item  row property Name   null                     return item             endregion

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A more  magic  way  and doesn t need  NET 3 5   If  for example  DBDatatable was returning a single column of Guids  uniqueidentifier in SQL  then you could use   Dim gList As New List Of Guid  gList AddRange DirectCast DBDataTable Select    IEnumerable Of Guid

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List lt Employee gt  emp   new List lt Employee gt        Maintaining DataTable on ViewState   For Demo only  DataTable dt   ViewState  CurrentEmp   as DataTable     read data from DataTable    using lamdaexpression   emp    from DataRow row in dt Rows     select new Employee              FirstName   row  FirstName   ToString            LastName   row  Last Name   ToString          ToList

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To assign the DataTable rows to the generic List of class    List lt Candidate gt  temp   new List lt Candidate gt      List that holds the Candidate Class        Note The Candidate class contains RollNo Name and Department       tb is DataTable     temp    from DataRow dr in tb Rows                         select new Candidate                                                         RollNO   Convert ToInt32 dr  RollNO                                 Name   dr  Name   ToString                                Department   dr  Department   ToString                                ToList

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If anyone want s to create custom function to convert datatable to list class Program       static void Main string   args                DataTable table   GetDataTable            var sw   new Stopwatch             sw Start            LinqMethod table           sw Stop            Console WriteLine  quot Elapsed time for Linq Method  0  quot   sw ElapsedMilliseconds            sw Reset             sw Start            ForEachMethod table           sw Stop            Console WriteLine  quot Elapsed time for Foreach method  0  quot   sw ElapsedMilliseconds            Console ReadKey               private static DataTable GetDataTable                 var table   new DataTable            table Columns Add  quot ID quot   typeof double            table Columns Add  quot CategoryName quot   typeof string            table Columns Add  quot Active quot   typeof double             var rand   new Random             for  int i   0  i  lt  100000  i                          table Rows Add i   quot name quot    i   rand Next 0  2                      return table             private static void LinqMethod DataTable table                var list   table AsEnumerable                Skip 1               Select dr   gt                  new Category                                       Id   Convert ToInt32 dr Field lt double gt   quot ID quot                         CategoryName   dr Field lt string gt   quot CategoryName quot                                              IsActive                               dr Field lt double gt   quot Active quot      1   true   false                    ToList              private static void ForEachMethod DataTable table                var categoryList   new List lt Category gt  table Rows Count           foreach  DataRow row in table Rows                        var values   row ItemArray              var category   new Category                                 Id   Convert ToInt32 values 0                    CategoryName   Convert ToString values 1                                       IsActive    double values 2     1   true   false                            categoryList Add category                        private class Category               public int Id   get  set            public string CategoryName   get  set            public bool IsActive   get  set             If we execute above code  Foreach method finishes in 56ms while linq one takes 101ms   for 1000 records   So Foreach method is better to use  Source Ways to Convert Datatable to List in C   with performance test example

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If you re using  NET 3 5  you can use DataTableExtensions AsEnumerable  an extension method  and then if you really need a List lt DataRow gt  instead of just IEnumerable lt DataRow gt  you can call Enumerable ToList   IEnumerable lt DataRow gt  sequence   dt AsEnumerable      or  using System Linq      List lt DataRow gt  list   dt AsEnumerable   ToList

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you can use following two Generic functions  private static List lt T gt  ConvertDataTable lt T gt  DataTable dt                List lt T gt  data   new List lt T gt             foreach  DataRow row in dt Rows                        T item   GetItem lt T gt  row               data Add item                     return data            private static T GetItem lt T gt  DataRow dr                 Type temp   typeof T           T obj   Activator CreateInstance lt T gt              foreach  DataColumn column in dr Table Columns                        foreach  PropertyInfo pro in temp GetProperties                                  if  pro Name    column ColumnName                      pro SetValue obj  dr column ColumnName  ToString    null                   else                     continue                                  return obj          and use it as following   List lt StudentScanExamsDTO gt  studentDetails   ConvertDataTable lt StudentScanExamsDTO gt  dt

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Use System Data namespace then you will get  AsEnumerable

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you can use following two Generic functions  private static List lt T gt  ConvertDataTable lt T gt  DataTable dt                List lt T gt  data   new List lt T gt             foreach  DataRow row in dt Rows                        T item   GetItem lt T gt  row               data Add item                     return data            private static T GetItem lt T gt  DataRow dr                 Type temp   typeof T           T obj   Activator CreateInstance lt T gt              foreach  DataColumn column in dr Table Columns                        foreach  PropertyInfo pro in temp GetProperties                                  if  pro Name    column ColumnName                      pro SetValue obj  dr column ColumnName  ToString    null                   else                     continue                                  return obj          and use it as following   List lt StudentScanExamsDTO gt  studentDetails   ConvertDataTable lt StudentScanExamsDTO gt  dt

[c#] How do you convert a DataTable into a generic list?

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