- /// <summary>
- /// 獲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="p_w_picpathOriginalWidth">圖片的原始寬度</param>
- /// <param name="p_w_picpathOriginalHeight">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 p_w_picpathOriginalWidth, int p_w_picpathOriginalHeight)
- {
- double w = 0.0;
- double h = 0.0;
- double sw = Convert.ToDouble(p_w_picpathOriginalWidth);
- double sh = Convert.ToDouble(p_w_picpathOriginalHeight);
- 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 p_w_picpathFile, int thumMaxWidth, int thumMaxHeight)
- {
- System.Drawing.Image originalImage = null;
- System.Drawing.Image newImage = null;
- try
- {
- originalImage = System.Drawing.Image.FromFile(p_w_picpathFile);
- 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,並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爲指定大小,並返回調整後的內存流。
- /// </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>返回調整後的圖片的內存流</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>
- /// 將一個內存流保存爲磁盤文件。
- /// </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="p_w_picpathFile">圖片文件地址</param>
- /// <param name="waterImage">水印圖片(Image對象)</param>
- public static void CreateImageWaterMark(string p_w_picpathFile, System.Drawing.Image waterImage)
- {
- if (string.IsNullOrEmpty(p_w_picpathFile) || !File.Exists(p_w_picpathFile) || waterImage == null)
- {
- return;
- }
- System.Drawing.Image originalImage = System.Drawing.Image.FromFile(p_w_picpathFile);
- 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 p_w_picpathWithWater = System.Drawing.Image.FromStream(stream);
- p_w_picpathWithWater.Save(p_w_picpathFile);
- p_w_picpathWithWater.Dispose();
- }
- /// <summary>
- /// 對一個指定的圖片加上文字水印效果。
- /// </summary>
- /// <param name="p_w_picpathFile">圖片文件地址</param>
- /// <param name="waterText">水印文字內容</param>
- public static void CreateTextWaterMark(string p_w_picpathFile, string waterText)
- {
- if (string.IsNullOrEmpty(p_w_picpathFile) || string.IsNullOrEmpty(waterText) || !File.Exists(p_w_picpathFile))
- {
- return;
- }
- System.Drawing.Image originalImage = System.Drawing.Image.FromFile(p_w_picpathFile);
- 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 p_w_picpathWithWater = System.Drawing.Image.FromStream(stream);
- p_w_picpathWithWater.Save(p_w_picpathFile);
- p_w_picpathWithWater.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;
- }