/// <summary>/// 獲取一個圖片按等比例縮小后的大小。/// </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后的實際大小</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）生成一個指定大小的縮略圖。/// </summary>/// <param name="originalImage">原始圖片</param>/// <param name="thumMaxWidth">縮略圖的寬度</param>/// <param name="thumMaxHeight">縮略圖的高度</param>/// <returns>返回縮略圖的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>/// 對給定的一個圖片文件生成一個指定大小的縮略圖。/// </summary>/// <param name="originalImage">圖片的物理文件地址</param>/// <param name="thumMaxWidth">縮略圖的寬度</param>/// <param name="thumMaxHeight">縮略圖的高度</param>/// <returns>返回縮略圖的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>/// 對給定的一個圖片文件生成一個指定大小的縮略圖，并將縮略圖保存到指定位置。/// </summary>/// <param name="originalImageFile">圖片的物理文件地址</param>/// <param name="thumbNailImageFile">縮略圖的物理文件地址</param>/// <param name="thumMaxWidth">縮略圖的寬度</param>/// <param name="thumMaxHeight">縮略圖的高度</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>/// 將一個圖片的內存流調整為指定大小，并返回調整后的內存流。/// </summary>/// <param name="originalImageStream">原始圖片的內存流</param>/// <param name="newWidth">新圖片的寬度</param>/// <param name="newHeight">新圖片的高度</param>/// <returns>返回調整后的圖片的內存流</returns>public static MemoryStream ResizeImage(Stream originalImageStream, int newWidth, int newHeight){  MemoryStream newImageStream = null;  System.Drawing.Image newImage = Globals.GetThumbNailImage(System.Drawing.Image.FromStream(originalImageStream), newWidth, newHeight);  if (newImage != null)  {    newImageStream = new MemoryStream();    newImage.Save(newImageStream, ImageFormat.Jpeg);  }  return newImageStream;}/// <summary>/// 將一個內存流保存為磁盤文件。/// </summary>/// <param name="stream">內存流</param>/// <param name="newFile">目標磁盤文件地址</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水印效果。/// </summary>/// <param name="imageFile">圖片文件地址</param>/// <param name="waterImage">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水印效果。/// </summary>/// <param name="imageFile">圖片文件地址</param>/// <param name="waterText">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();}/// <summary>/// 判斷上傳組件是否包含內容。/// </summary>/// <param name="fileUpload">ASP.NET 2.0標準上傳組件</param>/// <returns>如果數據有效，則返回True，否則返回False</returns>public static bool IsAttachmentValid(FileUpload fileUpload){  if (fileUpload != null &&    fileUpload.PostedFile != null &&    !string.IsNullOrEmpty(fileUpload.PostedFile.FileName) &&    fileUpload.PostedFile.ContentLength > 0)  {    return true;  }  return false;}

public class ImageHelper{  #region " 水印存放的相對路徑 "  public static string GetLogoPath()  {    return "/images/logo.png";  ///水印圖路徑  }  #endregion  #region " 圖片水印 "  // <summary>  // 在圖片上生成圖片水印,此方法不支持Gif類型的圖片  // </summary>  // <param name="Path">原服務器圖片路徑</param>  // <param name="Path_syp">生成的帶圖片水印的圖片路徑</param>  // <param name="Path_sypf">水印圖片路徑</param>  public static void MarkImage(Stream InUploadImagePath, string inLogoImagePath, string InSavePath)  {    System.Drawing.Image Image = System.Drawing.Image.FromStream(InUploadImagePath);    System.Drawing.Image newimage = Image.FromFile(Current.Server.MapPath(inLogoImagePath));    Graphics g = Graphics.FromImage(Image);    g.DrawImage(newimage, new Rectangle(Image.Width - newimage.Width, Image.Height - newimage.Height, newimage.Width, newimage.Height), 0, 0, newimage.Width, newimage.Height, GraphicsUnit.Pixel);    try {      Image.Save(Current.Server.MapPath(InSavePath));    }    catch (Exception ex) {    }    finally {      g.Dispose();      Image.Dispose();      newimage.Dispose();    }  }  #endregion}