在派生类中键入复杂对象的类型

Question

I have bit complex problem. Rather its strange but its requirement. I have two different namespaces and both of them have same class structure. Class1 of namespace2 inherits class1 of namespace1. Each parameter of class are of other class type and each type is in respective namespace ie Type11 is in namespace 1 and Type21 is in namesapce 2(First digit denotes the namespace). Now in derived class constructor, I need to inherit to base class constructor. To do this, I need to type cast each object to its base class. But when I typecast the object. it shows error like 'cannot convert namespace1.Type21 to namespace2.Type11'

Note: namespace1 and namespace2 both are different class library projects.I am adding referance of namesapce1 project in namespace2 project. Type11, Type21 etc are class itself.

Here each type(ie Type11, Type12 etc.) is again class which having method parameters and properties of some other complex type.

Here is my sample code. I have tried to replicate the same scenario as I am facing in real.

namespace Namespace1
{
    public class TestClass1
    {
        private Type14 obj4;
        public Type15 obj5;
        public TestClass1()
        { 
        }

        public TestClass1(Type11 obj1)
        {
        }

        public TestClass1(Type11 obj1,Type12 obj2)
        {
        }

        public TestClass1(Type11 obj1,Type12 obj2,params Type13[] obj3) 
        {
        }
    }
}

namespace Namespace2
{
    public class TestClass1:Namespace1.TestClass1
    {
        private Type14 obj4;
        public Type15 obj5;

        public TestClass1():base()
        {  
        }

        public TestClass1(Type21 obj1):base((namespace1.Type11)obj1)
        {
        }

        public TestClass1(Type21 obj1,Type22 obj2):base((namespace1.Type11)obj1,(namespace1.Type12)obj2)
        {
        }

        public TestClass1(Type21 obj1,Type22 obj2,params Type23[] obj3):base((namespace1.Type11)obj1,(namespace1.Type12)obj2,(namespace1.Type13)obj3)
        {
        }
    }
}

Can anyone please tell me how can I do type casting in this case?

Answer 1

From what I gather Type11 and Type21 are not part of the same type hierarchy (ie, neither of them is a base class of the other).

There is no "default" way to type cast in this case. You have two options:

1. Write converters for the types and call these to convert. This is the only way if you cannot change the source code of the types.
2. Write conversion operators for the types, if you have access to the source code.

Assuming you have access to the source code, an explicit conversion operator for the type can be written as follows:

// Assuming Type11 and Type21 have the same Foo property
// Add the following inside Type11
public static explicit operator Type21(Type11 t)
{
    return new Type21 { Foo = t.Foo };
}

You can then cast explicitly from Type11 to Type21:

Type11 a = new Type11 { Foo = 123 };
Type21 b = (Type21)a;

You can even write an implicit casting operator by replacing explicit in the first example above with implicit , which enables you to assign without an explicit cast:

Type11 a = new Type11 { Foo = 123 };
Type21 b = a;

MSDN has more information on using conversion operators.