Printing only the active window in C#

Question

I want to print only the active window from a C# application. Using CopyFromScreen() does not work as it takes a screenshot and the window can be partially hidden by other transient windows appearing. So I tried PrintWindow():

private void printDocument1_PrintPage(object sender, PrintPageEventArgs e)
{
    e.Graphics.PageScale = 10.0f;
    Graphics g = e.Graphics;
    PrintWindow(this.Handle, g.GetHdc(), 0);
}

This produces a tiny stamp-sized printout of the window regardless of which PageScale I use. Any ideas?

EDIT This does the trick:

private void printDocument1_PrintPage(object sender, PrintPageEventArgs e)
{
    Graphics myGraphics = CreateGraphics();
    var bitmap = new Bitmap(Width, Height, myGraphics);
    DrawToBitmap(bitmap, new Rectangle(0, 0, bitmap.Width, bitmap.Height));
    e.Graphics.DrawImage(bitmap, 0, 0);
}

Answer 1

Some googling around, and I found: Copying content from a hidden or clipped window in XP?

It seems you will need to prepare a bitmap for storing the page:

// Takes a snapshot of the window hwnd, stored in the memory device context hdcMem
HDC hdc = GetWindowDC(hwnd);
if (hdc)
{
    HDC hdcMem = CreateCompatibleDC(hdc);
    if (hdcMem)
    {
        RECT rc;
        GetWindowRect(hwnd, &rc);

        HBITMAP hbitmap = CreateCompatibleBitmap(hdc, RECTWIDTH(rc), RECTHEIGHT(rc));
        if (hbitmap)
        {
            SelectObject(hdcMem, hbitmap);

            PrintWindow(hwnd, hdcMem, 0);

            DeleteObject(hbitmap);
        }
        DeleteObject(hdcMem);
    }
    ReleaseDC(hwnd, hdc);
}