Tim Van Wassenhove

Last month i’ve started programming with the .NET Framework using Visual Basic, C++.NET and C# on a daily basis. The first thing i noticed is that some useful functions that were available in kernel32.dll, user32.dll, etc. have been removed from the API. At pinvoke.net you find a summary of the functions in these DLLs and the PInvoke signatures.The most common approach is to build classes for the DLLs as following:

namespace InterOp {
  public class User32 {
    [DllImport("user32.dll")]
    public static extern IntPtr GetDesktopWindow();
    [DllImport("user32.dll")]
    public static extern IntPtr GetWindowDC(IntPtr hWnd);
    [DllImport("user32.dll")]
    public static extern IntPtr ReleaseDC(IntPtr hWnd, IntPtr hDC);
    [DllImport("user32.dll")]
    public static extern IntPtr GetWindowRect(IntPtr hWnd, RECT rect);
  }

  public  class GDI32 {
    [DllImport("gdi32.dll")]
    public static extern bool DeleteDC(IntPtr hDC);
    [DllImport("gdi32.dll")]
    public static extern bool DeleteObject(IntPtr hObject);
    [DllImport("gdi32.dll")]
    public static extern IntPtr SelectObject(IntPtr hDC, IntPtr hObject);
  }
}