Exemplo n.º 1
0
 /// <summary>
 /// 按比例缩放图片
 /// </summary>
 /// <param name="source"></param>
 /// <param name="target"></param>
 /// <param name="destHeight"></param>
 /// <param name="destWidth"></param>
 /// <returns></returns>
 public static bool GetThumbnail(string source, string target, int destWidth = 1024, int destHeight = 800)
 {
     try
     {
         if (!File.Exists(source))
         {
             return(false);
         }
         System.Drawing.Image imgSource = Image.FromFile(source);
         System.Drawing.Imaging.ImageFormat thisFormat = imgSource.RawFormat;
         int sW = 0, sH = 0;
         // 按比例缩放
         int sWidth      = imgSource.Width;
         int sHeight     = imgSource.Height;
         if (sHeight > destHeight || sWidth > destWidth)
         {
             if ((sWidth * destHeight) > (sHeight * destWidth))
             {
                 sW = destWidth;
                 sH = (destWidth * sHeight) / sWidth;
             }
             else
             {
                 sH = destHeight;
                 sW = (sWidth * destHeight) / sHeight;
             }
         }
         else
         {
             sW = sWidth;
             sH = sHeight;
         }
         Bitmap   outBmp = new Bitmap(destWidth, destHeight);
         Graphics g      = Graphics.FromImage(outBmp);
         g.Clear(Color.Transparent);
         // 设置画布的描绘质量
         g.CompositingQuality = CompositingQuality.HighQuality;
         g.SmoothingMode      = SmoothingMode.HighQuality;
         g.InterpolationMode  = InterpolationMode.HighQualityBicubic;
         g.DrawImage(imgSource, new Rectangle((destWidth - sW) / 2, (destHeight - sH) / 2, sW, sH), 0, 0, imgSource.Width, imgSource.Height, GraphicsUnit.Pixel);
         g.Dispose();
         // 以下代码为保存图片时,设置压缩质量
         ImageCodecInfo    myImageCodecInfo = GetEncoderInfo(FileContentType.GetMimeMapping(source));
         EncoderParameters encoderParams = new EncoderParameters();
         long[]            quality       = new long[1];
         quality[0] = 100;
         EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality);
         encoderParams.Param[0] = encoderParam;
         imgSource.Dispose();
         EncoderParameters myEncoderParameters = new EncoderParameters(1);
         myEncoderParameters.Param[0] = encoderParam;
         outBmp.Save(target, myImageCodecInfo, myEncoderParameters);
         return(true);
     }
     catch (Exception ex)
     {
         throw ex;
     }
 }
Exemplo n.º 2
0
        /// <summary>
        /// 压缩文件
        /// </summary>
        /// <param name="srcFile"></param>
        /// <param name="destFile"></param>
        /// <param name="level"></param>
        public static void Compress(string srcFile, string destFile, long level)
        {
            Bitmap srcBitMap = new Bitmap(srcFile);
            Stream s         = new FileStream(destFile, FileMode.Create);

            Compress(srcBitMap, s, level, FileContentType.GetMimeMapping(srcFile));
            s.Close();
        }
Exemplo n.º 3
0
        /// <summary>
        /// 图片压缩到字节数组
        /// </summary>
        /// <param name="srcFile"></param>
        /// <param name="level">0-100</param>
        /// <returns></returns>
        public static byte[] CompressToBytes(string srcFile, long level)
        {
            byte[] bs        = null;
            Bitmap srcBitMap = new Bitmap(srcFile);

            System.IO.MemoryStream ms = new MemoryStream();
            Compress(srcBitMap, ms, level, FileContentType.GetMimeMapping(srcFile));
            bs = ms.ToArray();
            ms.Close();
            return(bs);
        }