Compiler Warning (level 4) CS0028

'function declaration' has the wrong signature to be an entry point

The method declaration for Main was invalid: it was declared with an invalid signature. Main must be declared as static and it must return either int or void. For more information, see Main() and Command-Line Arguments.

The following sample generates CS0028:

// CS0028.cs  
// compile with: /W:4 /warnaserror  
public class a  
{  
    public static double Main(int i)   // CS0028  
    // Try the following line instead:  
    // public static void Main()  
    {  
    }  
}