Question

I have two methods that are identical.
one is

    public void ExtendFrameIntoClientArea(Window w, int amount)
    {
        if (internals.DwmIsCompositionEnabled())
        {
            WindowInteropHelper wi = new WindowInteropHelper(w);
            internals.DwmExtendFrameIntoClientArea(wi.Handle, new internals.MARGINS(amount));
        }
    }

and the other is

public void ExtendFrameIntoClientArea(this Window w,int amount)
        {
            this.ExtendFrameIntoClientArea(w, amount);
        }

One of them is an extension method and the other one is not. This however, results in an error “This call is ambiguous”

How would I work around this?

Answer 1

Extension methods should be static.

public static class XExtender
{
    public static void A(this X x)
    {
        x.A(x);
    }
}
public class X
{
    public void A(X x)
    {

    }
}

Extension methods should have a static class and a static method.