学步园

例子一:实现PictureBox的透明化。

1.1 调用WinAPI的类

  public class Pink<br /> {<br /> public static void DrawAlpha(Graphics gxBuffer, Image barImage, Rectangle barRect, byte transp)<br /> {<br /> using (Graphics gxSrc = Graphics.FromImage(barImage))<br /> {<br /> IntPtr hdcDst = gxBuffer.GetHdc();<br /> IntPtr hdcSrc = gxSrc.GetHdc();<br /> BlendFunction blendFunction = new BlendFunction();<br /> blendFunction.BlendOp = (byte)0;<br /> blendFunction.BlendFlags = (byte)0;<br /> blendFunction.SourceConstantAlpha = transp;<br /> blendFunction.AlphaFormat = (byte)0;<br /> AlphaBlend(hdcDst, barRect.Left, barRect.Top, barRect.Size.Width, barRect.Size.Height, hdcSrc, 0, 0, barImage.Width, barImage.Height, blendFunction);<br /> gxBuffer.ReleaseHdc(hdcDst);<br /> gxSrc.ReleaseHdc(hdcSrc);<br /> }<br /> }</p> <p> [DllImport("coredll.dll")]<br /> extern public static Int32 AlphaBlend(IntPtr hdcDest, Int32 xDest, Int32 yDest, Int32 cxDest, Int32 cyDest, IntPtr hdcSrc, Int32 xSrc, Int32 ySrc, Int32 cxSrc, Int32 cySrc, BlendFunction blendFunction);</p> <p> }

1.2在界面上重画PictrueBox(需要设置PictureBox为隐藏)

private void picboxZoomIn_Paint(object sender, PaintEventArgs e)<br /> {<br /> Bitmap bitmap = new Bitmap(@"/Program Files/Collecter/pic/zoomin.png");<br /> Image image = Image.FromHbitmap(bitmap.GetHbitmap());<br /> Rectangle rect=new Rectangle(0,0,30,30);<br /> Pink.DrawAlpha(e.Graphics, image, rect, 20);<br /> //e.Graphics.DrawImage(image, 30, 30);<br /> }