图片等比例缩放.doc

//按比例缩放图片
publicImageZoomPicture(ImageSourceImage,intTargetWidth,intTargetHeight)
{
intIntWidth;//新的图片宽
intIntHeight;//新的图片高
try
{
System.Drawing.Imaging.ImageFormatformat=SourceImage.RawFormat;
System.Drawing.BitmapSaveImage=newSystem.Drawing.Bitmap(TargetWidth,TargetHeight);
Graphicsg=Graphics.FromImage(SaveImage);
g.Clear(Color.White);

//计算缩放图片的大小

if(SourceImage.Width>TargetWidth&&SourceImage.Height<=TargetHeight)//宽度比目的图片宽度大，长度比目的图片长度小
{
IntWidth=TargetWidth;
IntHeight=(IntWidth*SourceImage.Height)/SourceImage.Width;
}
elseif(SourceImage.Width<=TargetWidth&&SourceImage.Height>TargetHeight)//宽度比目的图片宽度小，长度比目的图片长度大
{
IntHeight=TargetHeight;
IntWidth=(IntHeight*SourceImage.Width)/SourceImage.Height;
}
elseif(SourceImage.Width<=TargetWidth&&SourceImage.Height<=TargetHeight)//长宽比目的图片长宽都小
{
IntHeight（参考：http://www.linbayan8.com）=SourceImage.Width;
IntWidth=SourceImage.Height;
}
else//长宽比目的图片的长宽都大
{
IntWidth=TargetWidth;
IntHeight=(IntWidth*SourceImage.Height)/SourceImage.Width;
if(IntHeight>TargetHeight)//重新计算
{
IntHeight=TargetHeight;
IntWidth=(IntHeight*SourceImage.Width)/SourceImage.Height;
}
}

g.DrawImage(SourceImage,(TargetWidth-IntWidth)/2,(TargetHeight-IntHeight)/2,IntWidth,IntHeight);
SourceImage.Dispose();

returnSaveImage;
}
catch(Exceptionex)
{

}

returnnull;
}

其它：
c#在图像上动态加载文字
http://blog.163.com/chenjunfeng_2007/blog/static/11938508320101953010175/
C#图片裁剪与缩放
http://www.2cto.com/kf/201106/94121.html
C#图片剪裁类
http://www.oschina.net/code/snippet_250332_9189
C#图片处理高级应用(裁剪,缩放,清晰度,水印)
http://www.soaspx.com/dotnet/csharp/csharp_20110221_7226.html