asp.net圖片縮減和加浮水印程式

代碼如下

複製代碼

///<summary> /// 擷取一個圖片按等比例縮小後的大小。 ///</summary> ///<param name="maxWidth">需要縮小到的寬度</param> ///<param name="maxHeight">需要縮小到的高度</param> ///<param name="imageOriginalWidth">圖片的原始寬度</param> ///<param name="imageOriginalHeight">圖片的原始高度</param> ///<returns>返回圖片按等比例縮小後的實際大小</returns> public static Size GetNewSize(int maxWidth, int maxHeight, int imageOriginalWidth, int imageOriginalHeight) {     double w = 0.0;     double h = 0.0;     double sw = Convert.ToDouble(imageOriginalWidth);     double sh = Convert.ToDouble(imageOriginalHeight);     double mw = Convert.ToDouble(maxWidth);     double mh = Convert.ToDouble(maxHeight);     if (sw < mw && sh < mh)     {         w = sw;         h = sh;     }     else if ((sw / sh) > (mw / mh))     {         w = maxWidth;         h = (w * sh) / sw;     }     else     {         h = maxHeight;         w = (h * sw) / sh;     }     return new Size(Convert.ToInt32(w), Convert.ToInt32(h)); } ///<summary> /// 對給定的一個圖片（Image對象）產生一個指定大小的縮圖。 ///</summary> ///<param name="originalImage">原始圖片</param> ///<param name="thumMaxWidth">縮圖的寬度</param> ///<param name="thumMaxHeight">縮圖的高度</param> ///<returns>返回縮圖的Image對象</returns> public static System.Drawing.Image GetThumbNailImage(System.Drawing.Image originalImage, int thumMaxWidth, int thumMaxHeight) {     Size thumRealSize = Size.Empty;     System.Drawing.Image newImage = originalImage;     Graphics graphics = null;     try     {         thumRealSize = GetNewSize(thumMaxWidth, thumMaxHeight, originalImage.Width, originalImage.Height);         newImage = new Bitmap(thumRealSize.Width, thumRealSize.Height);         graphics = Graphics.FromImage(newImage);         graphics.CompositingQuality = CompositingQuality.HighQuality;         graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;         graphics.SmoothingMode = SmoothingMode.HighQuality;         graphics.Clear(Color.Transparent);         graphics.DrawImage(originalImage, new Rectangle(0, 0, thumRealSize.Width, thumRealSize.Height), new Rectangle(0, 0, originalImage.Width, originalImage.Height), GraphicsUnit.Pixel);     }     catch { }     finally     {         if (graphics != null)         {             graphics.Dispose();             graphics = null;         }     }     return newImage; } ///<summary> /// 對給定的一個圖片檔案產生一個指定大小的縮圖。 ///</summary> ///<param name="originalImage">圖片的物理檔案地址</param> ///<param name="thumMaxWidth">縮圖的寬度</param> ///<param name="thumMaxHeight">縮圖的高度</param> ///<returns>返回縮圖的Image對象</returns> public static System.Drawing.Image GetThumbNailImage(string imageFile, int thumMaxWidth, int thumMaxHeight) {     System.Drawing.Image originalImage = null;     System.Drawing.Image newImage = null;     try     {         originalImage = System.Drawing.Image.FromFile(imageFile);         newImage = GetThumbNailImage(originalImage, thumMaxWidth, thumMaxHeight);     }     catch { }     finally     {         if (originalImage != null)         {             originalImage.Dispose();             originalImage = null;         }     }     return newImage; } ///<summary> /// 對給定的一個圖片檔案產生一個指定大小的縮圖，並將縮圖儲存到指定位置。 ///</summary> ///<param name="originalImageFile">圖片的物理檔案地址</param> ///<param name="thumbNailImageFile">縮圖的物理檔案地址</param> ///<param name="thumMaxWidth">縮圖的寬度</param> ///<param name="thumMaxHeight">縮圖的高度</param> public static void MakeThumbNail(string originalImageFile, string thumbNailImageFile, int thumMaxWidth, int thumMaxHeight) {     System.Drawing.Image newImage = GetThumbNailImage(originalImageFile, thumMaxWidth, thumMaxHeight);     try     {         newImage.Save(thumbNailImageFile, ImageFormat.Jpeg);     }     catch     { }     finally     {         newImage.Dispose();         newImage = null;     } } ///<summary> /// 將一個圖片的記憶體流調整為指定大小，並返回調整後的記憶體流。 ///</summary> ///<param name="originalImageStream">原始圖片的記憶體流</param> ///<param name="newWidth">新圖片的寬度</param> ///<param name="newHeight">新圖片的高度</param> ///<returns>返回調整後的圖片的記憶體流</returns> public static MemoryStream ResizeImage(Stream originalImageStream, int newWidth, int newHeight) {     MemoryStream newImageStream = null;     System.Drawing.Image newImage = GetThumbNailImage(System.Drawing.Image.FromStream(originalImageStream), newWidth, newHeight);     if (newImage != null)     {         newImageStream = new MemoryStream();         newImage.Save(newImageStream, ImageFormat.Jpeg);     }     return newImageStream; } ///<summary> /// 將一個記憶體流儲存為磁碟檔案。 ///</summary> ///<param name="stream">記憶體流</param> ///<param name="newFile">目標磁碟檔案地址</param> public static void SaveStreamToFile(Stream stream, string newFile) {     if (stream == null || stream.Length == 0 || string.IsNullOrEmpty(newFile))     {         return;     }     byte[] buffer = new byte[stream.Length];     stream.Position = 0;     stream.Read(buffer, 0, buffer.Length);     FileStream fileStream = new FileStream(newFile, FileMode.OpenOrCreate, FileAccess.Write);     fileStream.Write(buffer, 0, buffer.Length);     fileStream.Flush();     fileStream.Close();     fileStream.Dispose(); } ///<summary> /// 對一個指定的圖片加上圖片浮水印效果。 ///</summary> ///<param name="imageFile">圖片檔案地址</param> ///<param name="waterImage">浮水印圖片（Image對象）</param> public static void CreateImageWaterMark(string imageFile, System.Drawing.Image waterImage) {     if (string.IsNullOrEmpty(imageFile) || !File.Exists(imageFile) || waterImage == null)     {         return;     }     System.Drawing.Image originalImage = System.Drawing.Image.FromFile(imageFile);     if (originalImage.Width - 10 < waterImage.Width || originalImage.Height - 10 < waterImage.Height)     {         return;     }     Graphics graphics = Graphics.FromImage(originalImage);     int x = originalImage.Width - waterImage.Width - 10;     int y = originalImage.Height - waterImage.Height - 10;     int width = waterImage.Width;     int height = waterImage.Height;     graphics.DrawImage(waterImage, new Rectangle(x, y, width, height), 0, 0, width, height, GraphicsUnit.Pixel);     graphics.Dispose();     MemoryStream stream = new MemoryStream();     originalImage.Save(stream, ImageFormat.Jpeg);     originalImage.Dispose();     System.Drawing.Image imageWithWater = System.Drawing.Image.FromStream(stream);     imageWithWater.Save(imageFile);     imageWithWater.Dispose(); } ///<summary> /// 對一個指定的圖片加上文字浮水印效果。 ///</summary> ///<param name="imageFile">圖片檔案地址</param> ///<param name="waterText">浮水印文字內容</param> public static void CreateTextWaterMark(string imageFile, string waterText) {     if (string.IsNullOrEmpty(imageFile) || string.IsNullOrEmpty(waterText) || !File.Exists(imageFile))     {         return;     }     System.Drawing.Image originalImage = System.Drawing.Image.FromFile(imageFile);     Graphics graphics = Graphics.FromImage(originalImage);     graphics.SmoothingMode = SmoothingMode.HighQuality;     graphics.TextRenderingHint = TextRenderingHint.ClearTypeGridFit;     graphics.CompositingQuality = CompositingQuality.HighQuality;     graphics.InterpolationMode = InterpolationMode.HighQualityBicubic;     SolidBrush brush = new SolidBrush(Color.FromArgb(153, 255, 255, 255));     Font waterTextFont = new Font("Arial", 16, FontStyle.Regular);     SizeF waterTextSize = graphics.MeasureString(waterText, waterTextFont);     float x = (float)originalImage.Width - waterTextSize.Width - 10F;     float y = (float)originalImage.Height - waterTextSize.Height - 10F;     graphics.DrawString(waterText, waterTextFont, brush, x, y);     graphics.Dispose();     brush.Dispose();     MemoryStream stream = new MemoryStream();     originalImage.Save(stream, ImageFormat.Jpeg);     originalImage.Dispose();     System.Drawing.Image imageWithWater = System.Drawing.Image.FromStream(stream);     imageWithWater.Save(imageFile);     imageWithWater.Dispose(); }