大家知道，开发项目除了数据访问层很重要外，就是Common了，这里就提供了强大且实用的工具。
【C#公共帮助类】 Convert帮助类
Image类：
using System; using System.Collections.Generic; using System.Text; using System.IO; using System.Drawing.Imaging; using System.Drawing; using System.Web; namespace Common {public static class Image{#region 图片格式转换/// <summary>/// 图片格式转换/// </summary>/// <param name="OriFilename">原始文件相对路径</param>/// <param name="DesiredFilename">生成目标文件相对路径</param>/// <returns></returns>/// JPG采用的是有损压缩所以JPG图像有可能会降低图像清晰度，而像素是不会降低的 /// GIF采用的是无损压缩所以GIF图像是不会降低原图图像清晰度和像素的，但是GIF格式只支持256色图像。public static bool ConvertImage(string OriFilename, string DesiredFilename){string extname = DesiredFilename.Substring(DesiredFilename.LastIndexOf('.')+1).ToLower();ImageFormat DesiredFormat;//根据扩张名，指定ImageFormatswitch (extname){case "bmp":DesiredFormat = ImageFormat.Bmp;break;case "gif":DesiredFormat = ImageFormat.Gif;break;case "jpeg":DesiredFormat = ImageFormat.Jpeg;break;case "ico":DesiredFormat = ImageFormat.Icon;break;case "png":DesiredFormat = ImageFormat.Png;break;default:DesiredFormat = ImageFormat.Jpeg;break;}try{System.Drawing.Image imgFile = System.Drawing.Image.FromFile(WebPathTran(OriFilename));imgFile.Save(WebPathTran(DesiredFilename), DesiredFormat);return true;}catch {return false;}}#endregion#region 图片缩放/// <summary>/// 图片固定大小缩放/// </summary>/// <param name="OriFileName">源文件相对地址</param>/// <param name="DesiredFilename">目标文件相对地址</param>/// <param name="IntWidth">目标文件宽</param>/// <param name="IntHeight">目标文件高</param>/// <param name="imageFormat">图片文件格式</param>public static bool ChangeImageSize(string OriFileName, string DesiredFilename, int IntWidth, int IntHeight, ImageFormat imageFormat){string SourceFileNameStr =WebPathTran(OriFileName); //来源图片名称路径string TransferFileNameStr = WebPathTran(DesiredFilename); //目的图片名称路径FileStream myOutput =null;try{System.Drawing.Image.GetThumbnailImageAbort myAbort = new System.Drawing.Image.GetThumbnailImageAbort(imageAbort);Image SourceImage = System.Drawing.Image.FromFile(OriFileName);//来源图片定义Image TargetImage = SourceImage.GetThumbnailImage(IntWidth, IntHeight, myAbort, IntPtr.Zero); //目的图片定义//将TargetFileNameStr的图片放宽为IntWidth，高为IntHeight myOutput = new FileStream(TransferFileNameStr, FileMode.Create, FileAccess.Write, FileShare.Write);TargetImage.Save(myOutput, imageFormat);myOutput.Close();return true;}catch {myOutput.Close();return false;}}private static bool imageAbort(){return false;}#endregion#region 文字水印/// <summary>/// 文字水印/// </summary>/// <param name="wtext">水印文字</param>/// <param name="source">原图片物理文件名</param>/// <param name="target">生成图片物理文件名</param>public static bool ImageWaterText(string wtext,string source, string target){bool resFlag = false;Image image = Image.FromFile(source);Graphics graphics = Graphics.FromImage(image);try{graphics.DrawImage(image, 0, 0, image.Width, image.Height);Font font = new System.Drawing.Font("Verdana", 60);Brush brush = new System.Drawing.SolidBrush(System.Drawing.Color.Green);graphics.DrawString(wtext, font, brush, 35, 35);image.Save(target);resFlag = true;}catch (Exception){throw;}finally {graphics.Dispose();image.Dispose();}return resFlag;}#endregion#region 图片水印/// <summary>/// 在图片上生成图片水印/// </summary>/// <param name="Path">原服务器图片路径</param>/// <param name="Path_syp">生成的带图片水印的图片路径</param>/// <param name="Path_sypf">水印图片路径</param>public static bool ImageWaterPic(string source, string target, string waterPicSource){bool resFlag = false;Image sourceimage = Image.FromFile(source);Graphics sourcegraphics = Graphics.FromImage(sourceimage);Image waterPicSourceImage = Image.FromFile(waterPicSource);try{sourcegraphics.DrawImage(waterPicSourceImage, new System.Drawing.Rectangle(sourceimage.Width - waterPicSourceImage.Width, sourceimage.Height - waterPicSourceImage.Height, waterPicSourceImage.Width, waterPicSourceImage.Height), 0, 0, waterPicSourceImage.Width, waterPicSourceImage.Height, GraphicsUnit.Pixel);sourceimage.Save(target);}catch (Exception){throw;}finally{sourcegraphics.Dispose();sourceimage.Dispose();waterPicSourceImage.Dispose();}return resFlag;}#endregion/// <summary>/// 路径转换（转换成绝对路径）/// </summary>/// <param name="path"></param>/// <returns></returns>private static string WebPathTran(string path){try{return HttpContext.Current.Server.MapPath(path);}catch{return path;}}} }
