asp.net簡易圖片壓縮，縮圖實現

1.建立一個圖片壓縮類。

public Image ResourceImage;
        public string ErrorMessage;
        public ImageThumbnail(string ImageFileName)
        {
            ResourceImage = Image.FromFile(ImageFileName);
            ErrorMessage = string.Empty;
        }
        public bool ThumbnailCallback()
        {
            return false;
        }

       
        /// <summary>
        /// 方法一：可以自訂圖片的高度和寬度
        /// </summary>
        /// <param name="Width">圖片寬度</param>
        /// <param name="Height">圖片高度</param>
        /// <param name="targetFilePath">圖片路徑</param>
        /// <returns></returns>       
        public bool ReducedImage(int Width, int Height, string targetFilePath)
        {
            #region//處理縮圖的方法
            try
            {
                Image ReducedImage;
                Image.GetThumbnailImageAbort callb = new Image.GetThumbnailImageAbort(ThumbnailCallback);
                ReducedImage = ResourceImage.GetThumbnailImage(Width, Height, callb, IntPtr.Zero);
                ReducedImage.Save(@targetFilePath, ImageFormat.Jpeg);
                ReducedImage.Dispose();
                return true;
            }
            catch (Exception e)
            {
                ErrorMessage = e.Message;
                SystemErrorLogbll.inserErrorLog(e.Message + ":" + e.Source + ":" + e.TargetSite + ":ImageThumbnail.ReducedImage()處理縮圖的方法異常");
                return false;
            }
            #endregion
        }

        #region

        方法2，按百分比  縮小60% Percent為0.6 targetFilePath為目標路徑
        public bool ReducedImage(double Percent, string targetFilePath)
        {
            try
            {
                Image ReducedImage;
                Image.GetThumbnailImageAbort callb = new Image.GetThumbnailImageAbort(ThumbnailCallback);
                ImageWidth = Convert.ToInt32(ResourceImage.Width * Percent);
                ImageHeight = (ResourceImage.Height) * ImageWidth / ResourceImage.Width;//等比例縮放
               ReducedImage = ResourceImage.GetThumbnailImage(ImageWidth, ImageHeight, callb, IntPtr.Zero);
                ReducedImage.Save(@targetFilePath, ImageFormat.Jpeg);
                ReducedImage.Dispose();
                return true;
            }
            catch (Exception e)
            {
                ErrorMessage = e.Message;
                return false;
            }
       }

2.調用:ImageThumbnail imgy = new ImageThumbnail(圖片路徑);
            imgy.ReducedImage(103,68, 產生位置);

       通過測試，探索方法一產生的圖片在效果上要優於方法二，如果需要圖片達到更好的效果可以使用Graphics繪製縮圖做進一步的修改。