【C#公共帮助类】 Image帮助类
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。
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ImageFormat switch (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; } } } }
