[C#] 生成略缩图

来源：互联网发布：淘宝联盟退税sina 编辑：程序博客网时间：2024/05/02 21:23

// 生成略缩图
   string strImage = null;
   string strRegex = @".*?)(""|')?(/s|>)";
   MatchCollection mc = Regex.Matches( FreeTextBox.Text
    , strRegex,RegexOptions.IgnoreCase | RegexOptions.Singleline
    );
   foreach(Match m in mc)
   {
                strImage = m.Groups["src"].ToString();
    string strSrcImgPath = Server.UrlDecode(Server.MapPath(strImage));

if( !File.Exists(strSrcImgPath) )
break;

    string strDestImgPath =
     Server.MapPath(GV.s_strSmallImgPath)
     + GV.GetFileChecksum(strSrcImgPath)
     + ".jpg";

System.Drawing.Image srcImg = System.Drawing.Image.FromFile(strSrcImgPath);

    // 计算略缩图大小
    float cx, cy;
    if( srcImg.Height > GV.s_fSmallImgHeight )
    {
     // 比例系数
     float k = (float)srcImg.Height / GV.s_fSmallImgHeight;
     cy = srcImg.Height / k;
     cx = srcImg.Width / k;
    }
    else
    {
     cx = srcImg.Width;
     cy = srcImg.Height;
    }

    // 创建略缩图
    System.Drawing.Image.GetThumbnailImageAbort callb =
     new System.Drawing.Image.GetThumbnailImageAbort(ThumbnailCallback);
    System.Drawing.Image destImg = srcImg.GetThumbnailImage( (int)cx
     , (int)cy
     , callb
     , new System.IntPtr() );

srcImg.Dispose();

destImg.Save( strDestImgPath, ImageFormat.Jpeg);
destImg.Dispose();

    int nIndex = strDestImgPath.LastIndexOf("//");
    rs.PutCollect( "SmallImg",
     strDestImgPath.Substring( nIndex + 1, strDestImgPath.Length - nIndex - 1) );

    break;
   }