Is there way to check whether a Form has a Form Border? (by handle)

Question

I want to check whether a form has a Form Border by its handle. And, the handle is from the another Application.

How can I handle this? Please help me.. Thanks!

Answer 1

[DllImport("user32.dll")]
extern static int GetWindowLong(IntPtr hWnd, int nIndex);

const int GWL_STYLE = -16;
const int WS_BORDER = 0x00800000;  // thin border
const int WS_THICKFRAME = 0x00040000;  // sizing (thick) border

public static bool NativeWindowHasBorder(IntPtr hWnd)
{
     return (GetWindowLong(hWnd, GWL_STYLE) & (WS_BORDER | WS_THICKFRAME)) != 0;
}

Answer 2

Controls themselves don't actually have a handle. Control.Handle actually returns it's parent window's .Handle.

From MSDN for Control.Handle:

Gets the window handle that the control is bound to.

If you look at the decompiled source for Control, you'll see:

internal IntPtr HandleInternal
{
  get
  {
    return this.window.Handle;
  }
}

---

Edit

What I've stated above is completely incorrect. I'm leaving it for historical sake.

One can prove this very easily by putting a Button on a Form, and looking at the IntPtr Handle value for them. They are different.