if(fileupload.postedfile!=null)
     {    
      //addto為要添加的屬性，aboutfile為文件說(shuō)明
      string nam = fileupload.postedfile.filename ;
      //取得文件名(抱括路徑)里最后一個(gè)"."的索引
      int i= nam.lastindexof(".");
      //取得文件擴(kuò)展名
      string newext =nam.substring(i);
      //這里我自動(dòng)根據(jù)日期和文件大小不同為文件命名,確保文件名不重復(fù)
      datetime now = datetime.now;
      string newname=now.dayofyear.tostring()+fileupload.postedfile.contentlength.tostring();
      //保存文件到你所要的目錄,這里是iis根目錄下的upload目錄.你可以改變.
      //注意: 我這里用server.mappath()取當(dāng)前文件的相對(duì)目錄.在asp.net里"/"必須用"http://"代替，把"upload//"改成"http://upload//"就成了取當(dāng)前文件的絕對(duì)目錄了
      fileupload.postedfile.saveas(server.mappath("upload//"+newname+newext));
      //得到這個(gè)文件的相關(guān)屬性:文件名,文件類型,文件大小
      //fname.text=myfile.postedfile.filename;
      //fenc.text=myfile.postedfile.contenttype ;
      //fsize.text=myfile.postedfile.contentlength.tostring();
      //下面是生成縮略圖
      system.drawing.image image,anewimage;
      int width,height,newwidth,newheight;      
      image=system.drawing.image.fromfile(server.mappath("upload/"+newname.tostring()+newext.tostring()));
      system.drawing.image.getthumbnailimageabort callb =new system.drawing.image.getthumbnailimageabort(thumbnailcallback);    
      width=image.width;
      height=image.height;
      if(firstpageshow.selectedvalue.tostring()=="1"&&fenlei.selectedvalue.tostring()=="5")
      {
       newwidth=203;newheight=86;       
       newheight=height*newwidth/width;
      }
      else if(isweekman.selectedvalue.tostring()=="1")
      {
       newwidth=171;newheight=111;
       newheight=height*newwidth/width;
      }
      else if(firstpageshow.selectedvalue.tostring()=="1"&&fenlei.selectedvalue.tostring()=="3")
      {
       newwidth=171;newheight=111;
       newheight=height*newwidth/width;
      }
      else
      {
       newwidth=62;newheight=80;
       newheight=height*newwidth/width;
      }
      anewimage=image.getthumbnailimage(newwidth,newheight,callb,new system.intptr());
      anewimage.save(server.mappath("upload//"+"small_"+newname+newext));
      image.dispose();
      //生成縮略圖 生成并保存完畢，保存名是在原圖名前加了一個(gè)small_。
      pic="upload/"+newname.tostring()+newext.tostring();
      smallpic="upload/small_"+newname.tostring()+newext.tostring();
     }