Convert generic list to dataset in C

Question

I have a Generic list of Objects  Each object has 9 string properties  I want to turn that list into a dataset that i can pass to a datagridview      Whats the best way to go about doing this

User · Answer

You could create an extension method to add all property values through reflection   public static DataSet ToDataSet lt T gt  this IList lt T gt  list        Type elementType   typeof T       DataSet ds   new DataSet        DataTable t   new DataTable        ds Tables Add t          add a column to table for each public property on T     foreach var propInfo in elementType GetProperties                  t Columns Add propInfo Name  propInfo PropertyType                go through each property on T and add each value to the table     foreach T item in list                DataRow row   t NewRow            foreach var propInfo in elementType GetProperties                          row propInfo Name    propInfo GetValue item  null                        return ds

User · Answer

There is a bug with Lee s extension code above  you need to add the newly filled row to the table t when iterating throught the items in the list   public static DataSet ToDataSet lt T gt  this IList lt T gt  list     Type elementType   typeof T   DataSet ds   new DataSet    DataTable t   new DataTable    ds Tables Add t      add a column to table for each public property on T foreach var propInfo in elementType GetProperties          t Columns Add propInfo Name  propInfo PropertyType        go through each property on T and add each value to the table foreach T item in list        DataRow row   t NewRow        foreach var propInfo in elementType GetProperties                      row propInfo Name    propInfo GetValue item  null                This line was missing      t Rows Add row       return ds

User · Answer

I apologize for putting an answer up to this question  but I figured it would be the easiest way to view my final code   It includes fixes for nullable types and null values  -       public static DataSet ToDataSet lt T gt  this IList lt T gt  list                Type elementType   typeof T           DataSet ds   new DataSet            DataTable t   new DataTable            ds Tables Add t              add a column to table for each public property on T         foreach  var propInfo in elementType GetProperties                          Type ColType   Nullable GetUnderlyingType propInfo PropertyType     propInfo PropertyType               t Columns Add propInfo Name  ColType                        go through each property on T and add each value to the table         foreach  T item in list                        DataRow row   t NewRow                 foreach  var propInfo in elementType GetProperties                                  row propInfo Name    propInfo GetValue item  null     DBNull Value                             t Rows Add row                      return ds

User · Answer

Have you tried binding the list to the datagridview directly  If not  try that first because it will save you lots of pain  If you have tried it already  please tell us what went wrong so we can better advise you  Data binding gives you different behaviour depending on what interfaces your data object implements  For example  if your data object only implements IEnumerable  e g  List   you will get very basic one-way binding  but if it implements IBindingList as well  e g  BindingList  DataView   then you get two-way binding

User · Answer

One option would be to use a System ComponenetModel BindingList rather than a list   This allows you to use it directly within a DataGridView  And unlike a normal System Collections Generic List updates the DataGridView on changes

User · Answer

Brute force code to answer your question   DataTable dt   new DataTable       for each of your properties dt Columns Add  PropertyOne   typeof string     foreach Entity entity in entities      DataRow row   dt NewRow         foreach of your properties   row  PropertyOne     entity PropertyOne     dt Rows Add row      DataSet ds   new DataSet    ds Tables Add dt   return ds    Now for the actual question   Why would you want to do this   As mentioned earlier  you can bind directly to an object list   Maybe a reporting tool that only takes datasets

User · Answer

I have slightly modified the accepted answer by handling value types  I came across this when trying to do the following and because GetProperties   is zero length for value types I was getting an empty dataset  I know this is not the use case for the OP but thought I d post this change in case anyone else came across the same thing   Enumerable Range 1  10  ToList   ToDataSet        public static DataSet ToDataSet lt T gt  this IList lt T gt  list        var elementType   typeof T       var ds   new DataSet        var t   new DataTable        ds Tables Add t        if  elementType IsValueType                var colType   Nullable GetUnderlyingType elementType     elementType          t Columns Add elementType Name  colType          else                 add a column to table for each public property on T         foreach  var propInfo in elementType GetProperties                          var colType   Nullable GetUnderlyingType propInfo PropertyType     propInfo PropertyType              t Columns Add propInfo Name  colType                          go through each property on T and add each value to the table     foreach  var item in list                var row   t NewRow             if  elementType IsValueType                        row elementType Name    item                    else                       foreach  var propInfo in elementType GetProperties                                  row propInfo Name    propInfo GetValue item  null     DBNull Value                                  t Rows Add row              return ds

User · Answer

I found this code on Microsoft forum    This is so far one of easiest way  easy to understand and use  This has saved me hours   I have customized it as extension method without any  change to actual method  Below is the  code  it doesn t require much explanation    You can use two function signature with same implementation  1  public static DataSet ToDataSetFromObject this object dsCollection   2  public static DataSet ToDataSetFromArrayOfObject  this object   arrCollection    I  ll be using this one for example       lt summary gt     Serialize Object to XML and then read it into a DataSet      lt  summary gt      lt param name  arrCollection  gt Array of object lt  param gt      lt returns gt dataset lt  returns gt   public static DataSet ToDataSetFromArrayOfObject  this object   arrCollection        DataSet ds   new DataSet        try           XmlSerializer serializer   new XmlSerializer arrCollection GetType           System IO StringWriter sw   new System IO StringWriter            serializer Serialize sw  dsCollection           System IO StringReader reader   new System IO StringReader sw ToString             ds ReadXml reader         catch  Exception ex            throw  new Exception  Error While Converting Array of Object to Dataset                return ds      To use this extension in code   Country   objArrayCountry   null  objArrayCountry           populate your array if   objArrayCountry    null         dataset   objArrayCountry ToDataSetFromArrayOfObject

[c#] Convert generic list to dataset in C#

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