想做一个象qq一样的抓图工具但是做在这里不会了

[StructLayout(LayoutKind.Sequential)] public struct RECT { public int left; public int top; public int right; public int bottom; } [DllImport("user32.dll")] public static extern bool DrawFocusRect(int hwnd,RECT rc); 请问这个int hwnd怎么写呀．不知道怎么弄　，谢谢！最好有代吗！