RichTextBox PrintWindow -- let's get real

[WoodBeeProgrammer]

How come everybody on this newsgroup answers easy questions but not hard
questions?

Does PrintWindow work with RichTextBox? If not, WHY NOT? And if not,
what's the workaround?

TIA


[DllImport ("User32.dll")]
public extern static bool PrintWindow (System.IntPtr hWnd, System.IntPtr dc,
uint reservedFlag);

System.IntPtr hwnd = rtf.Handle;
Bitmap bm = new Bitmap (rtf.Size.Width, rtf.Size.Height);
if (bm != null)
{
using (Graphics g = Graphics.FromImage (bm))
{
if (g == null) return null;
System.IntPtr bmDC = g.GetHdc ();
bool ok = PrintWindow (hwnd, bmDC, 0); // RETURNS FALSE-- WHY?????
g.ReleaseHdc (bmDC);
}
}
return bm;

 

[Rami Saad]

class Test {
delegate bool CallBack(int hWnd, int lParam);
[DllImport("user32.dll")]
static extern int EnumWindows(CallBack hWnd, int lParam);
static bool PrintWindow(int hWnd, int lParam) {
Console.WriteLine(hWnd);
return true;
}
static void Main() {
CallBack e = new CallBack(PrintWindow);
EnumWindows(e, 0);
}
}

 

[WoodBeeProgrammer]

Rami, thanks for answering this post, i don't understand what i should do
with the class Test. I'm trying to use the PrintWindow function defined in
User32.dll to render the contents of a RichTextBox offscreen.

class Test {
delegate bool CallBack(int hWnd, int lParam);
[DllImport("user32.dll")]
static extern int EnumWindows(CallBack hWnd, int lParam);
static bool PrintWindow(int hWnd, int lParam) {
Console.WriteLine(hWnd);
return true;
}
static void Main() {
CallBack e = new CallBack(PrintWindow);
EnumWindows(e, 0);
}
}

--
Rami Saad
Microsoft GTSC Developer support for Middle East

How come everybody on this newsgroup answers easy questions but not hard
questions?

Does PrintWindow work with RichTextBox? If not, WHY NOT? And if not,
what's the workaround?

TIA


[DllImport ("User32.dll")]
public extern static bool PrintWindow (System.IntPtr hWnd, System.IntPtr dc,
uint reservedFlag);

System.IntPtr hwnd = rtf.Handle;
Bitmap bm = new Bitmap (rtf.Size.Width, rtf.Size.Height);
if (bm != null)
{
using (Graphics g = Graphics.FromImage (bm))
{
if (g == null) return null;
System.IntPtr bmDC = g.GetHdc ();
bool ok = PrintWindow (hwnd, bmDC, 0); // RETURNS FALSE-- WHY?????
g.ReleaseHdc (bmDC);
}
}
return bm;