Compiler Error CS0179

'member' cannot be extern and declare a body

When a class member is marked extern, it means that the member's definition is located in another file. Therefore, a class member marked as extern cannot be defined in the class. Either remove the extern keyword or delete the definition. For more information, see Methods.

The following sample generates CS0179:

// CS0179.cs  
public class MyClass  
{  
   public extern int ExternMethod(int aa)   // CS0179  
   {  
      return 0;  
   }  
   // try the following line instead  
   // public extern int ExternMethod(int aa);  
  
   public static void Main()  
   {  
   }  
}