Compiler Error CS0017

Program 'output file name' has more than one entry point defined. Compile with /main to specify the type that contains the entry point.

A program can only have one Main method.

Note

This warning is only reported during explicit Build or Rebuild operations. It does not appear during typing in the IDE as part of IntelliSense diagnostics. This means that if you fix the warning by using the field or removing it, the warning might persist in the error list until you build or rebuild the project again.

To resolve this error, you can either delete all Main methods in your code, except one, or you can use the StartupObject compiler option to specify which Main method you want to use.

The following sample generates CS0017:

// CS0017.cs  
// compile with: /target:exe  
public class clx  
{  
   static public void Main()  
   {  
   }  
}  
  
public class cly  
{  
   public static void Main()   // CS0017, delete one Main or use /main  
   {  
   }  
}