I have a method like this: (this is a generic method, and DYNAMIC_CLASS_TYPE
will be changed in situation to other situation)
Dim res = f.MyMethod(Of DYNAMIC_CLASS_TYPE)("select Id, Name from myTable")
I want to create a dynamic class, based on my query's columns and then pass the class instead of DYNAMIC_CLASS_TYPE
.
How can I do this?
I finally succeeded in doing it. My Code is as:
Public Shared Function CreateClass(ByVal className As String, ByVal properties As Dictionary(Of String, Type)) As Type
Dim myDomain As AppDomain = AppDomain.CurrentDomain
Dim myAsmName As New AssemblyName("MyAssembly")
Dim myAssembly As AssemblyBuilder = myDomain.DefineDynamicAssembly(myAsmName, AssemblyBuilderAccess.Run)
Dim myModule As ModuleBuilder = myAssembly.DefineDynamicModule("MyModule")
Dim myType As TypeBuilder = myModule.DefineType(className, TypeAttributes.Public)
myType.DefineDefaultConstructor(MethodAttributes.Public)
For Each o In properties
Dim prop As PropertyBuilder = myType.DefineProperty(o.Key, PropertyAttributes.HasDefault, o.Value, Nothing)
Dim field As FieldBuilder = myType.DefineField("_" + o.Key, o.Value, FieldAttributes.[Private])
Dim getter As MethodBuilder = myType.DefineMethod("get_" + o.Key, MethodAttributes.[Public] Or MethodAttributes.SpecialName Or MethodAttributes.HideBySig, o.Value, Type.EmptyTypes)
Dim getterIL As ILGenerator = getter.GetILGenerator()
getterIL.Emit(OpCodes.Ldarg_0)
getterIL.Emit(OpCodes.Ldfld, field)
getterIL.Emit(OpCodes.Ret)
Dim setter As MethodBuilder = myType.DefineMethod("set_" + o.Key, MethodAttributes.[Public] Or MethodAttributes.SpecialName Or MethodAttributes.HideBySig, Nothing, New Type() {o.Value})
Dim setterIL As ILGenerator = setter.GetILGenerator()
setterIL.Emit(OpCodes.Ldarg_0)
setterIL.Emit(OpCodes.Ldarg_1)
setterIL.Emit(OpCodes.Stfld, field)
setterIL.Emit(OpCodes.Ret)
prop.SetGetMethod(getter)
prop.SetSetMethod(setter)
Next
Return myType.CreateType()
End Function
The return value of the function is a Type of my Custom Class.