//
// Copyright ?2002 Rui Godinho Lopes <rui@ruilopes.com>
// 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;
Win32Class#region Win32Class
// a static class to expose needed win32 gdi functions.
class Win32
...{
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;
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;
}
[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);
DC About#region DC About
[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);
#endregion
}
#endregion
PerPixelAlphaFormClass#region PerPixelAlphaFormClass
/**//// <para>PerPixel forms should derive from this base class</para>
/// <author><name>Rui Godinho Lopes</name><email>rui@ruilopes.com</email></author>
class PerPixelAlphaForm : Form
...{
/**//// <para>Changes the current bitmap.</para>
public void SetBitmap(Bitmap bitmap)
...{
SetBitmap(bitmap, 255);
}
/**//// <para>Changes the current bitmap with a custom opacity level. Here is where all happens!</para>
public void SetBitmap(Bitmap bitmap, byte opacity)
...{
if (bitmap.PixelFormat != PixelFormat.Format32bppArgb)
throw new ApplicationException("The bitmap must be 32ppp with alpha-channel.");
// The ideia of this is very simple,
// 1. Create a compatible DC with screen;
// 2. Select the bitmap with 32bpp with alpha-channel in the compatible DC;
// 3. Call the UpdateLayeredWindow.
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);// select the newbitmap,return the oldbitmap
Win32.Size size = new Win32.Size(bitmap.Width, bitmap.Height);//create the size of LayeredWindow
Win32.Point pointSource = new Win32.Point(0, 0);
Win32.Point topPos = new Win32.Point(Left, Top);//LayeredWindow start position
Win32.BLENDFUNCTION blend = new Win32.BLENDFUNCTION();
/**//////????
blend.BlendOp = Win32.AC_SRC_OVER;
blend.BlendFlags = 0;
blend.SourceConstantAlpha = opacity;
blend.AlphaFormat = Win32.AC_SRC_ALPHA;
//the most important function
Win32.UpdateLayeredWindow(this.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);
}
}
protected override CreateParams CreateParams
...{
//set form style
get
...{
CreateParams cp = base.CreateParams;
cp.ExStyle |= 0x00080000; // This form has to have the WS_EX_LAYERED extended style
return cp;
}
}
}
#endregion
MyPerPixelAlphaFormClass#region MyPerPixelAlphaFormClass
/**//// <para>Our test form for this sample application. The bitmap will be displayed in this window.</para>
class MyPerPixelAlphaForm : PerPixelAlphaForm
...{
public MyPerPixelAlphaForm()
...{
Text = "PerPixelAlpha Layered Form";
TopMost = true;
FormBorderStyle = FormBorderStyle.FixedDialog;
MinimizeBox = false;
MaximizeBox = false;
ControlBox = false;
}
// Let Windows drag this window for us
protected override void WndProc(ref Message m)
...{
//Can move window
if (m.Msg == 0x0084 /**//*WM_NCHITTEST*/)
...{
m.Result= (IntPtr)2; // HTCLIENT
return;
}
base.WndProc(ref m);
}
}
#endregion
MainFormClass#region MainFormClass
/**////<para>The "controller" dialog box.</para>
class MyForm : Form
...{
public MyForm()
...{
Font= new Font("tahoma", 8);
Text= "perpixelalpha# - Sample application";
FormBorderStyle = FormBorderStyle.FixedDialog;
MinimizeBox = true;
MaximizeBox = false;
ClientSize = new Size(350, 160);
StartPosition = FormStartPosition.CenterScreen;
AllowDrop = true; // Because we want to be a drop target of windows explorer files.
InitializeComponent();
}
/**////<para>Constructs and initializes all child controls of this dialog box.</para>
private void InitializeComponent()
...{
// Label with to display current opacity level
Label Label1 = new Label();
Label1.AutoSize = true;
Label1.Location = new System.Drawing.Point(4, 8);
Label1.Text = "1. Drag&&Drop an image file from windows explorer into this window.";
Controls.Add(Label1);
Label Label2 = new Label();
Label2.AutoSize = true;
Label2.Location = new System.Drawing.Point(4, 38);
Label2.Text = "2. Play with the opacity level [0..255]:";
Controls.Add(Label2);
// Label with to display current opacity level
LabelValue = new Label();
LabelValue.AutoSize = true;
LabelValue.Location = new System.Drawing.Point(195, 38);
LabelValue.Text = "255";
Controls.Add(LabelValue);
// Trackbar to change opacity level
Track = new TrackBar();
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2010/5/28 14:34:00
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C#透明窗体(png图片渐变)源码