How to dynamic new Anonymous Class

Question

In C  3 0 you can create anonymous class with the following syntax  var o1   new   Id   1  Name    Foo       Is there a way to dynamic create these anonymous class to a variable     Example   var o1   new   Id   1  Name    Foo     var o2   new   SQ   2  Birth   DateTime Now        Dynamic create Example   var o1   DynamicNewAnonymous new NameValuePair  Id   1   new NameValuePair  Name    Foo     var o2   DynamicNewAnonymous new NameValuePair  SQ   2   new NameValuePair  Birth    DateTime Now      Beacuse I need to do   dynamic o1   new ExpandObject     o1  ID    1      lt -- ID  is dynamic name o1  Name     Foo     lt -- Name  is dynamic name   And Scene1   void ShowPropertiesValue object o      Type oType   o GetType      foreach var pi in oType GetProperties            Console WriteLine   0   1    pi Name  pi GetValue o  null            if I call   dynamic o1   new ExpandObject    o1 Name    123   ShowPropertiesValue o1     It can t show the result   Name   123   And also I how to Convert the ExpandoObject to AnonymouseType    Type type   o1 GetType    type GetProperties       lt --I hope it can get all property of o1   Last  I modify ShowPropertiesValue   method  void ShowPropertiesValue object o      if  o is static object    lt --How to check it is dynamic or static object          Type oType   o GetType        foreach var pi in oType GetProperties                Console WriteLine   0   1    pi Name  pi GetValue o  null                else if  o is dynamic object     lt --How to check it is dynamic or static object          foreach var pi in         lt --How to get common dynamic object s properties info               Console WriteLine   0   1    pi Name  pi GetValue o  null                   How to implement DynamicNewAnonymous method or how to modify the ShowPropertiesValue     My motivations is   dynamic o1   new MyDynamic    o1 Name    abc   Type o1Type   o1 GetType    var props   o1Type GetProperties     lt --I hope can get the Name Property   If i can hook dynamicObject s GetType Method  and Compel convert to strongly-typed Type  The above Seamless code can work fine

User · Accepted Answer

Anonymous types are just regular types that are implicitly declared. They have little to do with dynamic.

Now, if you were to use an ExpandoObject and reference it through a dynamic variable, you could add or remove fields on the fly.

edit

Sure you can: just cast it to IDictionary<string, object>. Then you can use the indexer.

You use the same casting technique to iterate over the fields:

dynamic employee = new ExpandoObject();
employee.Name = "John Smith";
employee.Age = 33;

foreach (var property in (IDictionary<string, object>)employee)
{
    Console.WriteLine(property.Key + ": " + property.Value);
}
// This code example produces the following output:
// Name: John Smith
// Age: 33

The above code and more can be found by clicking on that link.

User · Answer

You can create an ExpandoObject like this   IDictionary lt string object gt  expando   new ExpandoObject    expando  Name     value    And after casting it to dynamic  those values will look like properties   dynamic d   expando  Console WriteLine d Name     However  they are not actual properties and cannot be accessed using Reflection  So the following statement will return a null   d GetType   GetProperty  Name

User · Answer

Of cause it s possible to create dynamic classes using very cool ExpandoObject class   But recently I worked on project and faced that Expando Object is serealized in not the same format on xml as an simple Anonymous class  it was pity      that is why I decided to create my own class and share it with you  It s using reflection and dynamic directive   builds Assembly  Class and Instance truly dynamicly  You can add  remove and change properties that is included in your class on fly Here it is    using System  using System Collections Generic  using System Linq  using System Reflection  using System Reflection Emit  using static YourNamespace DynamicTypeBuilderTest   namespace YourNamespace            This class builds Dynamic Anonymous Classes      public class DynamicTypeBuilderTest                                      Create instance based on any Source class as example based on PersonalData                     public static object CreateAnonymousDynamicInstance PersonalData personalData  Type dynamicType  List lt ClassDescriptorKeyValue gt  classDescriptionList                        var obj   Activator CreateInstance dynamicType                var propInfos   dynamicType GetProperties                 classDescriptionList ForEach x   gt  SetValueToProperty obj  propInfos  personalData  x                 return obj                     private static void SetValueToProperty object obj  PropertyInfo   propInfos  PersonalData aisMessage  ClassDescriptorKeyValue description                        propInfos SingleOrDefault x   gt  x Name    description Name   SetValue obj  description ValueGetter aisMessage   null                      public static dynamic CreateAnonymousDynamicType string entityName  List lt ClassDescriptorKeyValue gt  classDescriptionList                        AssemblyName asmName   new AssemblyName                asmName Name      entityName Assembly               AssemblyBuilder assemblyBuilder   AssemblyBuilder DefineDynamicAssembly asmName  AssemblyBuilderAccess RunAndCollect                ModuleBuilder moduleBuilder   assemblyBuilder DefineDynamicModule    asmName Name Module                 TypeBuilder typeBuilder   moduleBuilder DefineType    entityName Dynamic   TypeAttributes Public                classDescriptionList ForEach x   gt  CreateDynamicProperty typeBuilder  x                 return typeBuilder CreateTypeInfo   AsType                       private static void CreateDynamicProperty TypeBuilder typeBuilder  ClassDescriptorKeyValue description                        CreateDynamicProperty typeBuilder  description Name  description Type                                     Creation Dynamic property  from MSDN  with some Magic                     public static void CreateDynamicProperty TypeBuilder typeBuilder  string name  Type propType                        FieldBuilder fieldBuider   typeBuilder DefineField    name ToLower   Field                                                               propType                                                              FieldAttributes Private                PropertyBuilder propertyBuilder   typeBuilder DefineProperty name                                                               PropertyAttributes HasDefault                                                               propType                                                               null                MethodAttributes getSetAttr                   MethodAttributes Public   MethodAttributes SpecialName                       MethodAttributes HideBySig               MethodBuilder methodGetBuilder                   typeBuilder DefineMethod   get  name                                               getSetAttr                                             propType                                             Type EmptyTypes                ILGenerator methodGetIL   methodGetBuilder GetILGenerator                 methodGetIL Emit OpCodes Ldarg 0               methodGetIL Emit OpCodes Ldfld  fieldBuider               methodGetIL Emit OpCodes Ret                MethodBuilder methodSetBuilder                   typeBuilder DefineMethod   set  name                                               getSetAttr                                             null                                             new Type     propType                  ILGenerator methodSetIL   methodSetBuilder GetILGenerator                 methodSetIL Emit OpCodes Ldarg 0               methodSetIL Emit OpCodes Ldarg 1               methodSetIL Emit OpCodes Stfld  fieldBuider               methodSetIL Emit OpCodes Ret                propertyBuilder SetGetMethod methodGetBuilder               propertyBuilder SetSetMethod methodSetBuilder                       public class ClassDescriptorKeyValue                       public ClassDescriptorKeyValue string name  Type type  Func lt PersonalData  object gt  valueGetter                                Name   name                  ValueGetter   valueGetter                  Type   type                             public string Name              public Type Type              public Func lt PersonalData  object gt  ValueGetter                                    Your Custom class description based on any source class for example             PersonalData         public static IEnumerable lt ClassDescriptorKeyValue gt  GetAnonymousClassDescription bool includeAddress  bool includeFacebook                        yield return new ClassDescriptorKeyValue  Id   typeof string   x   gt  x Id               yield return new ClassDescriptorKeyValue  Name   typeof string   x   gt  x FirstName               yield return new ClassDescriptorKeyValue  Surname   typeof string   x   gt  x LastName               yield return new ClassDescriptorKeyValue  Country   typeof string   x   gt  x Country               yield return new ClassDescriptorKeyValue  Age   typeof int    x   gt  x Age               yield return new ClassDescriptorKeyValue  IsChild   typeof bool   x   gt  x Age  lt  21                if  includeAddress                  yield return new ClassDescriptorKeyValue  Address   typeof string   x   gt  x  Contacts  Address                 if  includeFacebook                  yield return new ClassDescriptorKeyValue  Facebook   typeof string   x   gt  x  Contacts  Facebook                                       Source Data Class for example             of cause you can use any other class         public class PersonalData                        public int Id   get  set                public string FirstName   get  set                public string LastName   get  set                public string Country   get  set                public int Age   get  set                 public Dictionary lt string  string gt  Contacts   get  set                          It is also very simple to use DynamicTypeBuilder  you just need put few lines like this       public class ExampleOfUse               private readonly bool includeAddress          private readonly bool includeFacebook          private readonly dynamic dynamicType          private readonly List lt ClassDescriptorKeyValue gt  classDiscriptionList          public ExampleOfUse bool includeAddress   false  bool includeFacebook   false                        this includeAddress   includeAddress              this includeFacebook   includeFacebook              this classDiscriptionList   DynamicTypeBuilderTest GetAnonymousClassDescription includeAddress  includeFacebook  ToList                this dynamicType   DynamicTypeBuilderTest CreateAnonymousDynamicType  VeryPrivateData   this classDiscriptionList                      public object Map PersonalData privateInfo                        object dynamicObject   DynamicTypeBuilderTest CreateAnonymousDynamicInstance privateInfo  this dynamicType  classDiscriptionList                return dynamicObject                     I hope that this code snippet help somebody    Enjoy

[c#] How to dynamic new Anonymous Class?

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