// // Copyright © 2002 Rui Godinho Lopes // All rights reserved. // // This source file(s) may be redistributed unmodified by any means // PROVIDING they are not sold for profit without the authors expressed // written consent, and providing that this notice and the authors name // and all copyright notices remain intact. // // Any use of the software in source or binary forms, with or without // modification, must include, in the user documentation ("About" box and // printed documentation) and internal comments to the code, notices to // the end user as follows: // // "Portions Copyright © 2002 Rui Godinho Lopes" // // An email letting me know that you are using it would be nice as well. // That's not much to ask considering the amount of work that went into // this. // // THIS SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, // EXPRESS OR IMPLIED. USE IT AT YOUT OWN RISK. THE AUTHOR ACCEPTS NO // LIABILITY FOR ANY DATA DAMAGE/LOSS THAT THIS PRODUCT MAY CAUSE. // using System; using System.Drawing; using System.Drawing.Imaging; using System.Windows.Forms; using System.Runtime.InteropServices; namespace SpiffCode { // a static class to expose needed win32 gdi functions. class Win32 { public enum Bool { False= 0, True }; [StructLayout(LayoutKind.Sequential)] public struct Point { public Int32 x; public Int32 y; public Point(Int32 x, Int32 y) { this.x= x; this.y= y; } } [StructLayout(LayoutKind.Sequential)] public struct Size { public Int32 cx; public Int32 cy; public Size(Int32 cx, Int32 cy) { this.cx= cx; this.cy= cy; } } [StructLayout(LayoutKind.Sequential, Pack=1)] struct ARGB { public byte Blue; public byte Green; public byte Red; public byte Alpha; } [StructLayout(LayoutKind.Sequential, Pack=1)] public struct BLENDFUNCTION { public byte BlendOp; public byte BlendFlags; public byte SourceConstantAlpha; public byte AlphaFormat; } public const Int32 ULW_COLORKEY = 0x00000001; public const Int32 ULW_ALPHA = 0x00000002; public const Int32 ULW_OPAQUE = 0x00000004; public const byte AC_SRC_OVER = 0x00; public const byte AC_SRC_ALPHA = 0x01; [DllImport("user32.dll", ExactSpelling=true, SetLastError=true)] public static extern Bool UpdateLayeredWindow(IntPtr hwnd, IntPtr hdcDst, ref Point pptDst, ref Size psize, IntPtr hdcSrc, ref Point pprSrc, Int32 crKey, ref BLENDFUNCTION pblend, Int32 dwFlags); [DllImport("user32.dll", ExactSpelling=true, SetLastError=true)] public static extern IntPtr GetDC(IntPtr hWnd); [DllImport("user32.dll", ExactSpelling=true)] public static extern int ReleaseDC(IntPtr hWnd, IntPtr hDC); [DllImport("gdi32.dll", ExactSpelling=true, SetLastError=true)] public static extern IntPtr CreateCompatibleDC(IntPtr hDC); [DllImport("gdi32.dll", ExactSpelling=true, SetLastError=true)] public static extern Bool DeleteDC(IntPtr hdc); [DllImport("gdi32.dll", ExactSpelling=true)] public static extern IntPtr SelectObject(IntPtr hDC, IntPtr hObject); [DllImport("gdi32.dll", ExactSpelling=true, SetLastError=true)] public static extern Bool DeleteObject(IntPtr hObject); [DllImport("user32.dll", ExactSpelling=true, SetLastError=true)] public static extern Bool PrintWindow(IntPtr hwnd, IntPtr hdcBlt, UInt32 fl); [DllImport("gdi32.dll", ExactSpelling=true, SetLastError=true)] public static extern Bool MoveToEx(IntPtr hdc, Int32 x, Int32 y, IntPtr lpPoint); [DllImport("gdi32.dll", ExactSpelling=true, SetLastError=true)] public static extern Bool LineTo(IntPtr hdc, Int32 x, Int32 y); [DllImport("gdi32.dll", ExactSpelling=true, SetLastError=true)] public static extern Bool GdiFlush(); [DllImport("user32.dll", ExactSpelling=true, SetLastError=true)] public static extern Int32 SetWindowLong(IntPtr hwnd, Int32 index, Int32 value); } /// PerPixel forms should derive from this base class /// Rui Godinho Lopesrui@ruilopes.com public class PerPixelAlphaForm : Form { /// Changes the current bitmap. public void SetBitmap(Bitmap bitmap) { SetBitmap(bitmap, 255); } #if false /// Changes the current bitmap with a custom opacity level. Here is where all happens! public void SetBitmap(Bitmap bitmap, byte opacity) { if (bitmap.PixelFormat != PixelFormat.Format32bppArgb) throw new ApplicationException("The bitmap must be 32bpp with alpha-channel."); Bitmap bmWindow = new Bitmap(Width, Height, PixelFormat.Format32bppArgb); // NEW: // Bitmap bmWindow = bitmap; Graphics g = Graphics.FromImage(bmWindow); g.Clear(Color.FromArgb(0, 0, 0, 0)); g.DrawImage(bitmap, 0, 0, bmWindow.Width, bmWindow.Height); g.Flush(); IntPtr memDc = g.GetHdc(); // Win32.Bool fSuccess = Win32.PrintWindow(Handle, memDc, 0); // NEW: int err = Marshal.GetLastWin32Error(); if (err != 1400) { Win32.Size size = new Win32.Size(bmWindow.Width, bmWindow.Height); Win32.Point pointSource = new Win32.Point(0, 0); Win32.Point topPos = new Win32.Point(Left, Top); Win32.BLENDFUNCTION blend = new Win32.BLENDFUNCTION(); blend.BlendOp = Win32.AC_SRC_OVER; blend.BlendFlags = 0; blend.SourceConstantAlpha = opacity; blend.AlphaFormat = Win32.AC_SRC_ALPHA; Win32.GdiFlush(); // BackgroundImage = bmWindow; IntPtr screenDc = Win32.GetDC(IntPtr.Zero); Win32.UpdateLayeredWindow(Handle, screenDc, ref topPos, ref size, memDc, ref pointSource, 0, ref blend, Win32.ULW_ALPHA); Win32.ReleaseDC(IntPtr.Zero, screenDc); } g.ReleaseHdc(memDc); g.Dispose(); } #else public void SetBitmap(Bitmap bitmap, byte opacity) { if (bitmap.PixelFormat != PixelFormat.Format32bppArgb) throw new ApplicationException("The bitmap must be 32bpp with alpha-channel."); IntPtr screenDc = Win32.GetDC(IntPtr.Zero); IntPtr memDc = Win32.CreateCompatibleDC(screenDc); IntPtr hBitmap = IntPtr.Zero; IntPtr oldBitmap = IntPtr.Zero; try { hBitmap = bitmap.GetHbitmap(Color.FromArgb(0)); // grab a GDI handle from this GDI+ bitmap oldBitmap = Win32.SelectObject(memDc, hBitmap); Win32.Size size = new Win32.Size(bitmap.Width, bitmap.Height); Win32.Point pointSource = new Win32.Point(0, 0); Win32.Point topPos = new Win32.Point(Left, Top); Win32.BLENDFUNCTION blend = new Win32.BLENDFUNCTION(); blend.BlendOp = Win32.AC_SRC_OVER; blend.BlendFlags = 0; blend.SourceConstantAlpha = opacity; blend.AlphaFormat = Win32.AC_SRC_ALPHA; Win32.UpdateLayeredWindow(Handle, screenDc, ref topPos, ref size, memDc, ref pointSource, 0, ref blend, Win32.ULW_ALPHA); } finally { Win32.ReleaseDC(IntPtr.Zero, screenDc); if (hBitmap != IntPtr.Zero) { Win32.SelectObject(memDc, oldBitmap); //Windows.DeleteObject(hBitmap); // The documentation says that we have to use the Windows.DeleteObject... but since there is no such method I use the normal DeleteObject from Win32 GDI and it's working fine without any resource leak. Win32.DeleteObject(hBitmap); } Win32.DeleteDC(memDc); } } #endif protected override CreateParams CreateParams { get { CreateParams cp = base.CreateParams; cp.ExStyle |= 0x00080000; // This form has to have the WS_EX_LAYERED extended style return cp; } } public Bitmap SnapshotWindow() { Bitmap bm = new Bitmap(Width, Height, PixelFormat.Format32bppArgb); #if false IntPtr screenDc = Win32.GetDC(IntPtr.Zero); IntPtr memDc = Win32.CreateCompatibleDC(screenDc); IntPtr hBitmap = IntPtr.Zero; IntPtr oldBitmap = IntPtr.Zero; hBitmap = bm.GetHbitmap(); // grab a GDI handle from this GDI+ bitmap oldBitmap = Win32.SelectObject(memDc, hBitmap); Win32.PrintWindow(Handle, memDc, 0); Win32.ReleaseDC(IntPtr.Zero, screenDc); Win32.SelectObject(memDc, oldBitmap); // Win32.DeleteObject(hBitmap); Win32.DeleteDC(memDc); bm = Bitmap.FromHbitmap(hBitmap); #else Graphics g = Graphics.FromImage(bm); IntPtr hdcMem = g.GetHdc(); Win32.PrintWindow(Handle, hdcMem, 0); g.ReleaseHdc(hdcMem); g.Dispose(); #endif return bm; } protected override void OnPaint(PaintEventArgs e) { // base.OnPaint(e); } protected override void OnPaintBackground(PaintEventArgs e) { // base.OnPaintBackground(e); } } }