(i.e. a color that's not drawn). For speed purposes, I'm trying to
call the Win32 API function: TransparentBlt.
But the call is failing (and the image is not drawn), with an error
code of 126: "The specified module could not be found"
(ERROR_MOD_NOT_FOUND).
(The bitmap is loaded from a separate file called "bmp.bmp", any
bitmap renamed to that will do. I'm using Win XP Pro SP2 and
VStudio.NET 2003.)
Thanks a lot for your help!
<<
using System;
using System.Drawing;
using System.Windows.Forms;
using System.Runtime.InteropServices;
class MyForm : Form
{
Bitmap m_bmp;
public static void Main() { Application.Run(new MyForm()); }
public MyForm()
{
m_bmp = (Bitmap)Bitmap.FromFile("bmp.bmp");
}
[DllImport("user32.dll")]
public static extern IntPtr GetDC(IntPtr hwnd);
[DllImport("user32.dll")]
public static extern IntPtr ReleaseDC(IntPtr hwnd, IntPtr hdc);
[DllImport("gdi32.dll")]
public static extern IntPtr CreateCompatibleDC(IntPtr hdc);
[DllImport("gdi32.dll")]
public static extern int DeleteDC(IntPtr hObject);
[DllImport("gdi32.dll")]
public static extern IntPtr SelectObject(IntPtr hdc, IntPtr
hObject);
[DllImport("gdi32.dll")]
public static extern int DeleteObject(IntPtr hObject);
[DllImport("msimg32.dll")]
public static extern int TransparentBlt(IntPtr hdcDest, int
nXDest, int nYDest, int nWidth, int nHeight, IntPtr hdcSrc, int nXSrc,
int nYSrc, uint clr);
protected override void OnPaint(PaintEventArgs pea)
{
Graphics gfx = pea.Graphics;
IntPtr hBmp = m_bmp.GetHbitmap();
IntPtr hdcPanel = GetDC(this.Handle);
IntPtr hdcBmp = CreateCompatibleDC((IntPtr)null);
IntPtr hdcOld = SelectObject(hdcBmp, hBmp);
TransparentBlt(hdcPanel, 0, 0, 200, 200, hdcBmp, 0, 0, 0);
SelectObject(hdcBmp, hdcOld);
DeleteObject(hBmp);
DeleteDC(hdcBmp);
ReleaseDC(this.Handle, hdcPanel);
}
}
--Nick
