/// <summary> /// 壓縮圖片 /// </summary> /// <param name="fileStream">圖片流</param> /// <param name="quality">壓縮質量0-100之間 數值越大質量越高</param> /// <returns></returns> private byte[] CompressionImage(Stream fileStream, long quality) { using (System.Drawing.Image img = System.Drawing.Image.FromStream(fileStream)) { using (Bitmap bitmap = new Bitmap(img)) { ImageCodecInfo CodecInfo = GetEncoder(img.RawFormat); System.Drawing.Imaging.Encoder myEncoder = System.Drawing.Imaging.Encoder.Quality; EncoderParameters myEncoderParameters = new EncoderParameters(1); EncoderParameter myEncoderParameter = new EncoderParameter(myEncoder, quality); myEncoderParameters.Param[0] = myEncoderParameter; using (MemoryStream ms = new MemoryStream()) { bitmap.Save(ms, CodecInfo, myEncoderParameters); myEncoderParameters.Dispose(); myEncoderParameter.Dispose(); return ms.ToArray(); } } } } 調用:CompressionImage(stream,0L)//最低質量 1M jpg圖大概能壓成180k左右