改进版本v1.1。解决了生成较大缩略图时质量下降问题。现在的版本正确的叫法应改是缩放图了。哈哈
usingSystem;
usingSystem.Drawing;
usingSystem.Drawing.Imaging;
namespaceOnest.Cyclone.Business.util
{
///<summary>
///缩略图
///</summary>
publicclassMiniature
{
privateMiniature()
{
}
publicstaticvoidConvert(System.IO.Streamsrc,stringnewImagePath,intWidth,intHeight,stringCopyright)
{
System.Drawing.Imageoldimage=Image.FromStream(src,true,true);
intwidth;//缩略图的宽度
intheight;//缩略图的高度
if(oldimage.Width>oldimage.Height)//横向，颠倒一下尺寸设置
{
width=Height;//缩略图的宽度
height=Width;//缩略图的高度
}
else//纵向
{
//oldImagePath-原图地址newImagePath生成缩略图地址
width=Width;//缩略图的宽度
height=Height;//缩略图的高度
}
intlevel=100;//缩略图的质量1-100的范围
//System.Drawing.Imageoldimage=System.Drawing.Image.FromFile(oldImagePath);
//System.Drawing.ImagethumbnailImage=oldimage.GetThumbnailImage(width,height,newSystem.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback),IntPtr.Zero);
//Bitmapbm=newBitmap(thumbnailImage);
//newmethod
Bitmapbm=newBitmap(width,height);
Graphicsg=Graphics.FromImage(bm);
g.InterpolationMode=System.Drawing.Drawing2D.InterpolationMode.HighQualityBilinear;
g.DrawImage(oldimage,newRectangle(0,0,bm.Width,bm.Height),0,0,
oldimage.Width,oldimage.Height,GraphicsUnit.Pixel);
Graphics.FromImage(oldimage).DrawImage(bm,0,0,width,height);
//处理JPG质量的函数
ImageCodecInfo[]codecs=ImageCodecInfo.GetImageEncoders();
ImageCodecInfoici=null;
foreach(ImageCodecInfocodecincodecs)
{
if(codec.MimeType=="image/jpeg")
ici=codec;
}
EncoderParametersep=newEncoderParameters();
ep.Param[0]=newEncoderParameter(Encoder.Quality,(long)level);
#region制作水印
GraphicsgrPhoto=Graphics.FromImage(bm);
//用指定Sizes绘制图片时，测量用指定的字串宽度
//取可能的最大宽度
int[]sizes=newint[]{64,48,32,16,8,6,4};
FontcrFont=null;
SizeFcrSize=newSizeF();
for(inti=0;i<7;i++)
{
crFont=newFont("Verdana",sizes[i],
FontStyle.Bold);
crSize=grPhoto.MeasureString(Copyright,
crFont);
if((ushort)crSize.Width<(ushort)width)
break;
}
//指定做图点
intyPixlesFromBottom=(int)(height*.05);
floatyPosFromBottom=((height-
yPixlesFromBottom)-(crSize.Height/2));
floatxCenterOfImg=(width/2);
StringFormatStrFormat=newStringFormat();
StrFormat.Alignment=StringAlignment.Center;
//绘制copyright
SolidBrushsemiTransBrush2=newSolidBrush(Color.FromArgb(100,0,0,0));
grPhoto.DrawString(Copyright,crFont,semiTransBrush2,newPointF(xCenterOfImg+1,yPosFromBottom+1),StrFormat);
SolidBrushsemiTransBrush=newSolidBrush(Color.FromArgb(100,255,255,255));
grPhoto.DrawString(Copyright,crFont,semiTransBrush,newPointF(xCenterOfImg,yPosFromBottom),StrFormat);
#endregion
bm.Save(newImagePath,ici,ep);
try
{
//释放资源
ep.Dispose();
bm.Dispose();
oldimage.Dispose();
g.Dispose();
codecs=null;
StrFormat.Dispose();
semiTransBrush2.Dispose();
grPhoto.Dispose();
semiTransBrush.Dispose();
sizes=null;
}
catch{}
}
publicstaticvoidConvert(stringoldImagePath,stringnewImagePath,intWidth,intHeight,stringCopyright)
{
System.IO.StreamReadersr=newSystem.IO.StreamReader(oldImagePath);
Convert(sr.BaseStream,newImagePath,Width,Height,Copyright);
}
privatestaticboolThumbnailCallback(){returntrue;}
}
}
