Visual Basic

CType(CallByName(MyObject, "Child1", CallType.Get), HashSet(Of Child1)).ElementAt(k)

Enumerable.ElementAt(CallByName(MyObject, "Child1", CallType.Get), k)

Dim element = Enumerable.ElementAt(CallByName(MyObject, "Child1", CallType.Get), k)

Public Function CopyEntity(Of T As {Class, New})(ctx As MyEntities, entity As T, Optional copyKeys As Boolean = False) As T
       Dim clone As New T()
       Dim en = ctx.Entry(clone)
       en.State = System.Data.Entity.EntityState.Added
       ctx.Entry(clone).CurrentValues.SetValues(entity)
       en.State = System.Data.Entity.EntityState.Detached
       Return clone
   End Function

fhitm = CopyEntity(context, element,False)

An unhandled exception of type 'System.InvalidOperationException' occurred in EntityFramework.dll

Additional information: The entity type Object is not part of the model for the current context.

CTypeDynamic(Element,System.Type.Gettype("Child1"))

System.Type.Gettype("Child1")

Dim element = Enumerable.ElementAt(CallByName(MyObject, "Child1", CallType.Get), k)
REM "element" actually is of the type the elements of Child1 have
REM but at this point it's treated as type Object

REM so this generic function is called for the generic type Object
Public Function CopyEntity(Of T As {Class, New})(ctx As MyEntities, entity As T, ...) As T
    REM so "clone" actually is created as just an Object and not of the same type as "element" / "entity"
    Dim clone As New T()
    REM and the type Object of course isn't a valid entity-type in your context
    Dim en = ctx.Entry(clone)

// CEClass    : class that contains the function CopyEntity
// CEInstance : an instance of CEClass

MethodInfo mi = typeof(CEClass).GetMethod("CopyEntity");
mi = mi.MakeGenericMethod(typeof(MyEntities), element.GetType(), typeof(bool));
// you could cache "mi"

object clone = mi.Invoke(CEInstance, new object[] {context, element, false});

"REM so "clone" actually is created as just an Object and not of the same type as "element" / "entity"

Ctype(element,Child1)

System.Type.Gettype("Child1")

dilkonika wrote:

This is not true because I try to use this instruction :
--- and after that everything works correctly

dilkonika wrote:

the type specified as parameter inside CtypeDynamic

dilkonika wrote:

But where can I find the namespace for my entity object ?

Dim t a type
Dim s  as string = "MyProg1.Child1,MyProg1,Version=1.0.0, Culture=neutral,PublicKeyToken=null"
t=System.Type.GetType(s)

CTypeDynamic(Element,Child1)

Dim t a type
Dim s  as string = "MyProg1.Child1,MyProg1,Version=1.0.0, Culture=neutral,PublicKeyToken=null"
t=System.Type.GetType(s)
CtypeDynamic(Element,t)

An unhandled exception of type 'System.InvalidOperationException' occurred in EntityFramework.dll

Additional information: The entity type Object is not part of the model for the current context.

Dim element = CType(Enumerable.ElementAt(CallByName(MyObj1, "Child1", CallType.Get), k), Child1)

Dim element = CTypeDynamic(Enumerable.ElementAt(CallByName(MyObj1, "Child1", CallType.Get), k), Type.GetType("MyProg1.Child1,MyProg1,Version=1.0.0, Culture=neutral,PublicKeyToken=null"))

Dim el = Enumerable.ElementAt(CallByName(MyClass, "Children", CallType.Get), 1)

REM 1
Dim el1 = CType(el, ChildClass)
Dim el1copy = CopyEntity(el1)   REM works. (el1copy is of type ChildClass)

REM 2
Dim el2 = CTypeDynamic(Of ChildClass)(el)
Dim el2copy = CopyEntity(el2)   REM works. (el2copy is of type ChildClass)

REM 3
Dim el3 = CTypeDynamic(el, GetType(ChildClass))
Dim el3copy = CopyEntity(el3)   REM doesn't work. (el3copy is of type Object)

class ChildClass
{ }

class MyClass
{
    public ICollection<ChildClass> Children { get; set; }

    public MyClass()
    {
        Children = new HashSet<ChildClass>() { new ChildClass() };
    }
}

T CopyEntity<T>(T entity)
    where T : class, new()
{
    T copy = new T();
    // actual copying omitted here
    // for testing only the return type matters
    return copy;
}

void Test()
{
    MyClass myClass = new MyClass();
    dynamic children = typeof(MyClass).GetProperty("Children").GetValue(myClass);
    dynamic child = Enumerable.ElementAt(children, 0);
    dynamic copy = CopyEntity(child);
    // copy is of type ChildClass
}