ASP.NET中图片显示方法实例
本文实例讲述了ASP.NET中图片的显示方法。分享给大家供大家参考。具体如下：
genimage.ashx：
<%@WebHandlerLanguage="C#"Class="netpix.ImageGenerator"%>
genimage.ashx.cs：
//Copyright(C)2003byGregEnnis
//(mailto:greg@ennis.net)
//
//ThecontentsofthisfilearesubjecttotheArtisticLicense(the"License").
//YoumaynotusethisfileexceptincompliancewiththeLicense.
//YoumayobtainacopyoftheLicenseat:
//http://www.opensource.org/licenses/artistic-license.html
usingSystem;
usingSystem.Collections;
usingSystem.ComponentModel;
usingSystem.Data;
usingSystem.Data.SqlClient;
usingSystem.Drawing;
usingSystem.Web;
usingSystem.IO;
usingSystem.Configuration;
usingSystem.Web.SessionState;
usingSystem.Web.UI;
usingSystem.Web.UI.WebControls;
usingSystem.Web.UI.HtmlControls;
namespacenetpix
{
publicclassImageGenerator:IHttpHandler
{
publicboolIsReusable
{get{returntrue;}}
publicvoidProcessRequest(HttpContextContext)
{
//Gettheimagefilenameandalbumrootpathfromthedatabase
//图片浏览次数
intnumviews;
//图片数据库中的ID
intpicid=Convert.ToInt32(Context.Request["id"]);
//图片路径
stringimgpath=npdata.GetPathToPicture(picid,outnumviews);
//Writinganimagetooutputstream
Context.Response.ContentType="image/jpg";
//'thumbnail'meanswearerequestingathumbnail
//显示缩略图
if(Context.Request["thumbnail"]!=null)
{
//Needtoloadtheimage,resizeit,andstreamtotheclient.
//Calculatethescalesoasnottostretchordistorttheimage.
Bitmapbmp=newBitmap(imgpath);
floatscale=150.0f/System.Math.Max(bmp.Height,bmp.Width);
System.Drawing.Imagethumb=bmp.GetThumbnailImage((int)(bmp.Width*scale),(int)(bmp.Height*scale),null,System.IntPtr.Zero);
thumb.Save(Context.Response.OutputStream,System.Drawing.Imaging.ImageFormat.Jpeg);
bmp.Dispose();
thumb.Dispose();
}
else
{
//Streamdirectlyfromthefile
//Getthestreamandsenditouttheresponse
System.IO.FileStreamfs=File.Open(imgpath,FileMode.Open,FileAccess.Read,FileShare.Read);
constintbyteLength=8192;
byte[]bytes=newbyte[byteLength];
while(fs.Read(bytes,0,byteLength)!=0)
{
Context.Response.BinaryWrite(bytes);
}
fs.Close();
//更新数据库浏览次数
npdata.SetNumViews(picid,numviews+1);
}
}
}
}
使用方法：
imgCtrl.ImageUrl="genimage.ashx?id="+Request["id"];
希望本文所述对大家的ASP.NET程序设计有所帮助。