按指定的压缩质量及格式保存图片

    #region 按指定的压缩质量及格式保存图片（微软的Image.Save方法保存到图片压缩质量为75)
    /// <summary>
    /// 按指定的压缩质量及格式保存图片（微软的Image.Save方法保存到图片压缩质量为75)
    /// </summary>
    /// <param name="sourceImage">要保存的图片的Image对象</param>
    /// <param name="savePath">图片要保存的绝对路径</param>
    /// <param name="imageQualityValue">图片要保存的压缩质量，该参数的值为1至100的整数，数值越大，保存质量越好</param>
    /// <returns>保存成功，返回true；反之，返回false</returns>
    public static bool SaveImageForSpecifiedQuality(System.Drawing.Image sourceImage, string savePath, int imageQualityValue)
    {
        //以下代码为保存图片时，设置压缩质量
        EncoderParameters encoderParameters = new EncoderParameters();
        EncoderParameter encoderParameter = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, imageQualityValue);
        encoderParameters.Param[0] = encoderParameter;
        try
        {
            ImageCodecInfo[] ImageCodecInfoArray = ImageCodecInfo.GetImageEncoders();
            ImageCodecInfo jpegImageCodecInfo = null;
            for (int i = 0; i < ImageCodecInfoArray.Length; i++)
            {
                if (ImageCodecInfoArray[i].FormatDescription.Equals("JPEG"))
                {
                    jpegImageCodecInfo = ImageCodecInfoArray[i];
                    break;
                }
            }
            sourceImage.Save(savePath, jpegImageCodecInfo, encoderParameters);
            return true;
        }
        catch
        {
            return false;
        }
    }
    #endregion