How to: Explicitly Implement Members of Two Interfaces in C#

METHOD ---I

( If the two interface members perform the same function).

(If a class implements two interfaces that contain a member with the same signature, then implementing that member on the class will cause both interfaces to use that member as their implementation. In the following example, all the calls to Paint invoke the same method).


class Test
{
 static void Main()
  {
       SampleClass sc = new SampleClass();
       IControl ctrl = (IControl)sc;
       ISurface srfc = (ISurface)sc;

       // The following lines all call the same method.

       sc.Paint();
       ctrl.Paint();
       srfc.Paint();
   }
}


interface IControl
{
 void Paint();
}

 interface ISurface
{
void Paint();
 }

class SampleClass : IControl, ISurface
{
 // Both ISurface.Paint and IControl.Paint call this method.

public void Paint()
  {
    Console.WriteLine("Paint method in SampleClass");
   }
}

// Output:
// Paint method in SampleClass
// Paint method in SampleClass
// Paint method in SampleClass


======================================================================

METHOD --II

( If the two interface members do not perform the same function).


public class SampleClass : IControl, ISurface
{
    void IControl.Paint()
    {
        System.Console.WriteLine("IControl.Paint");
    }
    void ISurface.Paint()
    {
        System.Console.WriteLine("ISurface.Paint");
    }
}




// Call the Paint methods from Main.

SampleClass obj = new SampleClass();
//obj.Paint();  // Compiler error.

IControl c = (IControl)obj;
c.Paint();  // Calls IControl.Paint on SampleClass.

ISurface s = (ISurface)obj;
s.Paint(); // Calls ISurface.Paint on SampleClass.
// Output:
// IControl.Paint
// ISurface.Paint