void Example()
{
IntPtr hwnd = FindWindow(null, "Example.txt - Notepad2");
CaptureWindow(hwnd);
}
[DllImport("User32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool PrintWindow(IntPtr hwnd, IntPtr hDC, uint nFlags);
[DllImport("user32.dll")]
static extern bool GetWindowRect(IntPtr handle, ref Rectangle rect);
[DllImport("user32.dll", SetLastError = true)]
static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
public void CaptureWindow(IntPtr handle)
{
// Get the size of the window to capture
Rectangle rect = new Rectangle();
GetWindowRect(handle, ref rect);
// GetWindowRect returns Top/Left and Bottom/Right, so fix it
rect.Width = rect.Width - rect.X;
rect.Height = rect.Height - rect.Y;
// Create a bitmap to draw the capture into
using (Bitmap bitmap = new Bitmap(rect.Width, rect.Height))
{
// Use PrintWindow to draw the window into our bitmap
using (Graphics g = Graphics.FromImage(bitmap))
{
IntPtr hdc = g.GetHdc();
if (!PrintWindow(handle, hdc, 0))
{
int error = Marshal.GetLastWin32Error();
var exception = new System.ComponentModel.Win32Exception(error);
Debug.WriteLine("ERROR: " + error + ": " + exception.Message);
// TODO: Throw the exception?
}
g.ReleaseHdc(hdc);
}
// Save it as a .png just to demo this
bitmap.Save("Example.png");
}
}