使用方法：

UploadImage ui = new UploadImage(); /***可选参数***/ ui.SetWordWater = "哈哈";//文字水印 // ui.SetPicWater = Server.MapPath("2.png");//图片水印(图片和文字都赋值图片有效) ui.SetPositionWater = 4;//水印图片的位置 0居中、1左上角、2右上角、3左下角、4右下角 ui.SetSmallImgHeight = "110,40,20";//设置缩略图可以多个 ui.SetSmallImgWidth = "100,40,20"; //保存图片生成缩略图 var reponseMessage = ui.FileSaveAs(Request.Files[0], Server.MapPath("~/file/temp")); //裁剪图片 var reponseMessage2 = ui.FileCutSaveAs(Request.Files[0], Server.MapPath("~/file/temp2"), 400, 300, UploadImage.CutMode.CutNo); /***返回信息***/ var isError = reponseMessage.IsError;//是否异常 var webPath = reponseMessage.WebPath;//web路径 var filePath = reponseMessage.filePath;//物理路径 var message = reponseMessage.Message;//错误信息 var directory = reponseMessage.Directory;//目录 var smallPath1 = reponseMessage.SmallPath(0);//缩略图路径1 var smallPath2 = reponseMessage.SmallPath(1);//缩略图路径2 var smallPath3 = reponseMessage.SmallPath(2);//缩略图路径3

效果：

源码：

using System; using System.Collections.Generic; using System.Text; using System.IO; using System.Web; using System.Drawing; using System.Drawing.Imaging; using System.Drawing.Drawing2D; using System.Collections; using System.Net; using System.Text.RegularExpressions; using System.Configuration; namespace SyntacticSugar { /// <summary> /// ** 描述：图片上传类、支持水印、缩略图 /// ** 创始时间：2015-5-28 /// ** 修改时间：- /// ** 修改人：sunkaixuan /// </summary> public class UploadImage { #region 属性 /// <summary> /// 允许图片格式 /// </summary> public string SetAllowFormat { get; set; } /// <summary> /// 允许上传图片大小 /// </summary> public double SetAllowSize { get; set; } /// <summary> /// 文字水印字符 /// </summary> public string SetWordWater { get; set; } /// <summary> /// 图片水印 /// </summary> public string SetPicWater { get; set; } /// <summary> /// 水印图片的位置 0居中、1左上角、2右上角、3左下角、4右下角 /// </summary> public int SetPositionWater { get; set; } /// <summary> /// 缩略图宽度多个逗号格开（例如:200,100） /// </summary> public string SetSmallImgWidth { get; set; } /// <summary> /// 缩略图高度多个逗号格开（例如:200,100） /// </summary> public string SetSmallImgHeight { get; set; } /// <summary> /// 是否限制最大宽度，默认为true /// </summary> public bool SetLimitWidth { get; set; } /// <summary> /// 最大宽度尺寸，默认为600 /// </summary> public int SetMaxWidth { get; set; } /// <summary> /// 是否剪裁图片，默认true /// </summary> public bool SetCutImage { get; set; } /// <summary> /// 限制图片最小宽度，0表示不限制 /// </summary> public int SetMinWidth { get; set; } #endregion public UploadImage() { SetAllowFormat = ".jpeg|.jpg|.bmp|.gif|.png"; //允许图片格式 SetAllowSize = 1; //允许上传图片大小,默认为1MB SetPositionWater = 4; SetCutImage = true; } #region main method /// <summary> /// 裁剪图片 /// </summary> /// <param name="PostedFile">HttpPostedFile控件</param> /// <param name="SavePath">保存路径【sys.config配置路径】</param> /// <param name="oImgWidth">图片宽度</param> /// <param name="oImgHeight">图片高度</param> /// <param name="cMode">剪切类型</param> /// <param name="ext">返回格式</param> /// <returns>返回上传信息</returns> public ResponseMessage FileCutSaveAs(System.Web.HttpPostedFile PostedFile, string SavePath, int oImgWidth, int oImgHeight, CutMode cMode) { ResponseMessage rm = new ResponseMessage(); try { //获取上传文件的扩展名 string sEx = System.IO.Path.GetExtension(PostedFile.FileName); if (!CheckValidExt(SetAllowFormat, sEx)) { TryError(rm, 2); return rm; } //获取上传文件的大小 double PostFileSize = PostedFile.ContentLength / 1024.0 / 1024.0; if (PostFileSize > SetAllowSize) { TryError(rm, 3); return rm; //超过文件上传大小 } if (!System.IO.Directory.Exists(SavePath)) { System.IO.Directory.CreateDirectory(SavePath); } //重命名名称 string NewfileName = DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString() + DateTime.Now.Day.ToString() + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + DateTime.Now.Millisecond.ToString("000"); string fName = "s" + NewfileName + sEx; string fullPath = Path.Combine(SavePath, fName); PostedFile.SaveAs(fullPath); //重命名名称 string sNewfileName = DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString() + DateTime.Now.Day.ToString() + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + DateTime.Now.Millisecond.ToString("000"); string sFName = sNewfileName + sEx; rm.IsError = false; rm.FileName = sFName; string sFullPath = Path.Combine(SavePath, sFName); rm.filePath = sFullPath; rm.WebPath = "/"+sFullPath.Replace(HttpContext.Current.Server.MapPath("~/"), "").Replace("", "/"); CreateSmallPhoto(fullPath, oImgWidth, oImgHeight, sFullPath, SetPicWater, SetWordWater, cMode); if (File.Exists(fullPath)) { File.Delete(fullPath); } //压缩 if (PostFileSize > 100) { CompressPhoto(sFullPath, 100); } } catch (Exception ex) { TryError(rm, ex.Message); } return rm; } /// <summary> /// 通用图片上传类 /// </summary> /// <param name="PostedFile">HttpPostedFile控件</param> /// <param name="SavePath">保存路径【sys.config配置路径】</param> /// <param name="finame">返回文件名</param> /// <param name="fisize">返回文件大小</param> /// <returns>返回上传信息</returns> public ResponseMessage FileSaveAs(System.Web.HttpPostedFile PostedFile, string SavePath) { ResponseMessage rm = new ResponseMessage(); try { if (string.IsNullOrEmpty(PostedFile.FileName)) { TryError(rm, 4); return rm; } Random rd = new Random(); int rdInt = rd.Next(1000, 9999); //重命名名称 string NewfileName = DateTime.Now.Year.ToString() + DateTime.Now.Month.ToString() + DateTime.Now.Day.ToString() + DateTime.Now.Hour.ToString() + DateTime.Now.Minute.ToString() + DateTime.Now.Second.ToString() + DateTime.Now.Millisecond.ToString() + rdInt; //获取上传文件的扩展名 string sEx = System.IO.Path.GetExtension(PostedFile.FileName); if (!CheckValidExt(SetAllowFormat, sEx)) { TryError(rm, 2); return rm; } //获取上传文件的大小 double PostFileSize = PostedFile.ContentLength / 1024.0 / 1024.0; if (PostFileSize > SetAllowSize) { TryError(rm, 3); return rm; } if (!System.IO.Directory.Exists(SavePath)) { System.IO.Directory.CreateDirectory(SavePath); } rm.FileName = NewfileName + sEx; string fullPath = SavePath.Trim('') + "" + rm.FileName; rm.WebPath = "/"+fullPath.Replace(HttpContext.Current.Server.MapPath("~/"), "").Replace("", "/"); rm.filePath = fullPath; rm.Size = PostFileSize; PostedFile.SaveAs(fullPath); System.Drawing.Bitmap bmp = new Bitmap(fullPath); int realWidth = bmp.Width; int realHeight = bmp.Height; bmp.Dispose(); #region 检测图片宽度限制 if (SetMinWidth > 0) { if (realWidth < SetMinWidth) { TryError(rm, 7); return rm; } } #endregion #region 监测图片宽度是否超过600，超过的话，自动压缩到600 if (SetLimitWidth && realWidth > SetMaxWidth) { int mWidth = SetMaxWidth; int mHeight = mWidth * realHeight / realWidth; string tempFile = SavePath + Guid.NewGuid().ToString() + sEx; File.Move(fullPath, tempFile); CreateSmallPhoto(tempFile, mWidth, mHeight, fullPath, "", ""); File.Delete(tempFile); } #endregion #region 压缩图片存储尺寸 if (sEx.ToLower() != ".gif") { CompressPhoto(fullPath, 100); } #endregion //生成缩略图片高宽 if (string.IsNullOrEmpty(SetSmallImgWidth)) { rm.Message = "上传成功,无缩略图"; return rm; } string[] oWidthArray = SetSmallImgWidth.Split(','); string[] oHeightArray = SetSmallImgHeight.Split(','); if (oWidthArray.Length != oHeightArray.Length) { TryError(rm, 6); return rm; } for (int i = 0; i < oWidthArray.Length; i++) { if (Convert.ToInt32(oWidthArray[i]) <= 0 || Convert.ToInt32(oHeightArray[i]) <= 0) continue; string sImg = SavePath.TrimEnd('') + '' + NewfileName + "_" + i.ToString() + sEx; //判断图片高宽是否大于生成高宽。否则用原图 if (realWidth > Convert.ToInt32(oWidthArray[i])) { if (SetCutImage) CreateSmallPhoto(fullPath, Convert.ToInt32(oWidthArray[i]), Convert.ToInt32(oHeightArray[i]), sImg, "", ""); else CreateSmallPhoto(fullPath, Convert.ToInt32(oWidthArray[i]), Convert.ToInt32(oHeightArray[i]), sImg, "", "", CutMode.CutNo); } else { if (SetCutImage) CreateSmallPhoto(fullPath, realWidth, realHeight, sImg, "", ""); else CreateSmallPhoto(fullPath, realWidth, realHeight, sImg, "", "", CutMode.CutNo); } } #region 给大图添加水印 if (!string.IsNullOrEmpty(SetPicWater)) AttachPng(SetPicWater, fullPath); else if (!string.IsNullOrEmpty(SetWordWater)) AttachText(SetWordWater, fullPath); #endregion } catch (Exception ex) { TryError(rm, ex.Message); } return rm; } #region 验证格式 /// <summary> /// 验证格式 /// </summary> /// <param name="allType">所有格式</param> /// <param name="chkType">被检查的格式</param> /// <returns>bool</returns> public bool CheckValidExt(string allType, string chkType) { bool flag = false; string[] sArray = allType.Split('|'); foreach (string temp in sArray) { if (temp.ToLower() == chkType.ToLower()) { flag = true; break; } } return flag; } #endregion #region 根据需要的图片尺寸，按比例剪裁原始图片 /// <summary> /// 根据需要的图片尺寸，按比例剪裁原始图片 /// </summary> /// <param name="nWidth">缩略图宽度</param> /// <param name="nHeight">缩略图高度</param> /// <param name="img">原始图片</param> /// <returns>剪裁区域尺寸</returns> public Size CutRegion(int nWidth, int nHeight, Image img) { double width = 0.0; double height = 0.0; double nw = (double)nWidth; double nh = (double)nHeight; double pw = (double)img.Width; double ph = (double)img.Height; if (nw / nh > pw / ph) { width = pw; height = pw * nh / nw; } else if (nw / nh < pw / ph) { width = ph * nw / nh; height = ph; } else { width = pw; height = ph; } return new Size(Convert.ToInt32(width), Convert.ToInt32(height)); } #endregion #region 等比例缩小图片 public Size NewSize(int nWidth, int nHeight, Image img) { double w = 0.0; double h = 0.0; double sw = Convert.ToDouble(img.Width); double sh = Convert.ToDouble(img.Height); double mw = Convert.ToDouble(nWidth); double mh = Convert.ToDouble(nHeight); if (sw < mw && sh < mh) { w = sw; h = sh; } else if ((sw / sh) > (mw / mh)) { w = nWidth; h = (w * sh) / sw; } else { h = nHeight; w = (h * sw) / sh; } return new Size(Convert.ToInt32(w), Convert.ToInt32(h)); } #endregion #region 生成缩略图 #region 生成缩略图，不加水印 /// <summary> /// 生成缩略图，不加水印 /// </summary> /// <param name="filename">源文件</param> /// <param name="nWidth">缩略图宽度</param> /// <param name="nHeight">缩略图高度</param> /// <param name="destfile">缩略图保存位置</param> public void CreateSmallPhoto(string filename, int nWidth, int nHeight, string destfile) { Image img = Image.FromFile(filename); ImageFormat thisFormat = img.RawFormat; Size CutSize = CutRegion(nWidth, nHeight, img); Bitmap outBmp = new Bitmap(nWidth, nHeight); Graphics g = Graphics.FromImage(outBmp); // 设置画布的描绘质量 g.CompositingQuality = CompositingQuality.HighQuality; g.SmoothingMode = SmoothingMode.HighQuality; g.InterpolationMode = InterpolationMode.HighQualityBicubic; int nStartX = (img.Width - CutSize.Width) / 2; int nStartY = (img.Height - CutSize.Height) / 2; g.DrawImage(img, new Rectangle(0, 0, nWidth, nHeight), nStartX, nStartY, CutSize.Width, CutSize.Height, GraphicsUnit.Pixel); g.Dispose(); //if (thisFormat.Equals(ImageFormat.Gif)) //{ // Response.ContentType = "image/gif"; //} //else //{ // Response.ContentType = "image/jpeg"; //} // 以下代码为保存图片时，设置压缩质量 EncoderParameters encoderParams = new EncoderParameters(); long[] quality = new long[1]; quality[0] = 100; EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality); encoderParams.Param[0] = encoderParam; //获得包含有关内置图像编码解码器的信息的ImageCodecInfo 对象。 ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders(); ImageCodecInfo jpegICI = null; for (int x = 0; x < arrayICI.Length; x++) { if (arrayICI[x].FormatDescription.Equals("JPEG")) { jpegICI = arrayICI[x];//设置JPEG编码 break; } } if (jpegICI != null) { //outBmp.Save(Response.OutputStream, jpegICI, encoderParams); outBmp.Save(destfile, jpegICI, encoderParams); } else { //outBmp.Save(Response.OutputStream, thisFormat); outBmp.Save(destfile, thisFormat); } img.Dispose(); outBmp.Dispose(); } #endregion #region 生成缩略图，加水印 public void CreateSmallPhoto(string filename, int nWidth, int nHeight, string destfile, string sy, int nType) { if (nType == 0) CreateSmallPhoto(filename, nWidth, nHeight, destfile, sy, ""); else CreateSmallPhoto(filename, nWidth, nHeight, destfile, "", sy); } #endregion #region 生成缩略图 /// <summary> /// 生成缩略图 /// </summary> /// <param name="filename">源文件</param> /// <param name="nWidth">缩略图宽度</param> /// <param name="nHeight">缩略图高度</param> /// <param name="destfile">缩略图保存位置</param> /// <param name="png">图片水印</param> /// <param name="text">文本水印</param> public void CreateSmallPhoto(string filename, int nWidth, int nHeight, string destfile, string png, string text) { Image img = Image.FromFile(filename); ImageFormat thisFormat = img.RawFormat; Size CutSize = CutRegion(nWidth, nHeight, img); Bitmap outBmp = new Bitmap(nWidth, nHeight); Graphics g = Graphics.FromImage(outBmp); g.Clear(Color.White); // 设置画布的描绘质量 g.CompositingQuality = CompositingQuality.HighQuality; g.SmoothingMode = SmoothingMode.HighQuality; g.InterpolationMode = InterpolationMode.HighQualityBicubic; int nStartX = (img.Width - CutSize.Width) / 2; int nStartY = (img.Height - CutSize.Height) / 2; g.DrawImage(img, new Rectangle(0, 0, nWidth, nHeight), nStartX, nStartY, CutSize.Width, CutSize.Height, GraphicsUnit.Pixel); g.Dispose(); // 以下代码为保存图片时，设置压缩质量 EncoderParameters encoderParams = new EncoderParameters(); long[] quality = new long[1]; quality[0] = 100; EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality); encoderParams.Param[0] = encoderParam; //获得包含有关内置图像编码解码器的信息的ImageCodecInfo 对象。 ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders(); ImageCodecInfo jpegICI = null; for (int x = 0; x < arrayICI.Length; x++) { if (arrayICI[x].FormatDescription.Equals("JPEG")) { jpegICI = arrayICI[x];//设置JPEG编码 break; } } if (jpegICI != null) { outBmp.Save(destfile, jpegICI, encoderParams); } else { outBmp.Save(destfile, thisFormat); } img.Dispose(); outBmp.Dispose(); if (!string.IsNullOrEmpty(png)) AttachPng(png, destfile); if (!string.IsNullOrEmpty(text)) AttachText(text, destfile); } public void CreateSmallPhoto(string filename, int nWidth, int nHeight, string destfile, string png, string text, CutMode cMode) { Image img = Image.FromFile(filename); if (nWidth <= 0) nWidth = img.Width; if (nHeight <= 0) nHeight = img.Height; int towidth = nWidth; int toheight = nHeight; switch (cMode) { case CutMode.CutWH://指定高宽缩放（可能变形） break; case CutMode.CutW://指定宽，高按比例 toheight = img.Height * nWidth / img.Width; break; case CutMode.CutH://指定高，宽按比例 towidth = img.Width * nHeight / img.Height; break; case CutMode.CutNo: //缩放不剪裁 int maxSize = (nWidth >= nHeight ? nWidth : nHeight); if (img.Width >= img.Height) { towidth = maxSize; toheight = img.Height * maxSize / img.Width; } else { toheight = maxSize; towidth = img.Width * maxSize / img.Height; } break; default: break; } nWidth = towidth; nHeight = toheight; ImageFormat thisFormat = img.RawFormat; Size CutSize = new Size(nWidth, nHeight); if (cMode != CutMode.CutNo) CutSize = CutRegion(nWidth, nHeight, img); Bitmap outBmp = new Bitmap(CutSize.Width, CutSize.Height); Graphics g = Graphics.FromImage(outBmp); g.Clear(Color.White); // 设置画布的描绘质量 g.CompositingQuality = CompositingQuality.HighQuality; g.SmoothingMode = SmoothingMode.HighQuality; g.InterpolationMode = InterpolationMode.HighQualityBicubic; int nStartX = (img.Width - CutSize.Width) / 2; int nStartY = (img.Height - CutSize.Height) / 2; //int x1 = (outBmp.Width - nWidth) / 2; //int y1 = (outBmp.Height - nHeight) / 2; if (cMode != CutMode.CutNo) g.DrawImage(img, new Rectangle(0, 0, nWidth, nHeight), nStartX, nStartY, CutSize.Width, CutSize.Height, GraphicsUnit.Pixel); else g.DrawImage(img, new Rectangle(0, 0, nWidth, nHeight), 0, 0, img.Width, img.Height, GraphicsUnit.Pixel); g.Dispose(); // 以下代码为保存图片时，设置压缩质量 EncoderParameters encoderParams = new EncoderParameters(); long[] quality = new long[1]; quality[0] = 100; EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality); encoderParams.Param[0] = encoderParam; //获得包含有关内置图像编码解码器的信息的ImageCodecInfo 对象。 ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders(); ImageCodecInfo jpegICI = null; for (int x = 0; x < arrayICI.Length; x++) { if (arrayICI[x].FormatDescription.Equals("JPEG")) { jpegICI = arrayICI[x];//设置JPEG编码 break; } } if (jpegICI != null) { outBmp.Save(destfile, jpegICI, encoderParams); } else { outBmp.Save(destfile, thisFormat); } img.Dispose(); outBmp.Dispose(); if (!string.IsNullOrEmpty(png)) AttachPng(png, destfile); if (!string.IsNullOrEmpty(text)) AttachText(text, destfile); } #endregion #endregion #region 添加文字水印 public void AttachText(string text, string file) { if (string.IsNullOrEmpty(text)) return; if (!System.IO.File.Exists(file)) return; System.IO.FileInfo oFile = new System.IO.FileInfo(file); string strTempFile = System.IO.Path.Combine(oFile.DirectoryName, Guid.NewGuid().ToString() + oFile.Extension); oFile.CopyTo(strTempFile); Image img = Image.FromFile(strTempFile); ImageFormat thisFormat = img.RawFormat; int nHeight = img.Height; int nWidth = img.Width; Bitmap outBmp = new Bitmap(nWidth, nHeight); Graphics g = Graphics.FromImage(outBmp); g.Clear(Color.White); // 设置画布的描绘质量 g.CompositingQuality = CompositingQuality.HighQuality; g.SmoothingMode = SmoothingMode.HighQuality; g.InterpolationMode = InterpolationMode.HighQualityBicubic; g.DrawImage(img, new Rectangle(0, 0, nWidth, nHeight), 0, 0, nWidth, nHeight, GraphicsUnit.Pixel); int[] sizes = new int[] { 16, 14, 12, 10, 8, 6, 4 }; Font crFont = null; SizeF crSize = new SizeF(); //通过循环这个数组，来选用不同的字体大小 //如果它的大小小于图像的宽度，就选用这个大小的字体 for (int i = 0; i < 7; i++) { //设置字体，这里是用arial，黑体 crFont = new Font("arial", sizes[i], FontStyle.Bold); //Measure the Copyright string in this Font crSize = g.MeasureString(text, crFont); if ((ushort)crSize.Width < (ushort)nWidth) break; } //因为图片的高度可能不尽相同, 所以定义了 //从图片底部算起预留了5%的空间 int yPixlesFromBottom = (int)(nHeight * .08); //现在使用版权信息字符串的高度来确定要绘制的图像的字符串的y坐标 float yPosFromBottom = ((nHeight - yPixlesFromBottom) - (crSize.Height / 2)); //计算x坐标 float xCenterOfImg = (nWidth / 2); //把文本布局设置为居中 StringFormat StrFormat = new StringFormat(); StrFormat.Alignment = StringAlignment.Center; //通过Brush来设置黑色半透明 SolidBrush semiTransBrush2 = new SolidBrush(Color.FromArgb(153, 0, 0, 0)); //绘制版权字符串 g.DrawString(text, //版权字符串文本 crFont, //字体 semiTransBrush2, //Brush new PointF(xCenterOfImg + 1, yPosFromBottom + 1), //位置 StrFormat); //设置成白色半透明 SolidBrush semiTransBrush = new SolidBrush(Color.FromArgb(153, 255, 255, 255)); //第二次绘制版权字符串来创建阴影效果 //记住移动文本的位置1像素 g.DrawString(text, //版权文本 crFont, //字体 semiTransBrush, //Brush new PointF(xCenterOfImg, yPosFromBottom), //位置 StrFormat); g.Dispose(); // 以下代码为保存图片时，设置压缩质量 EncoderParameters encoderParams = new EncoderParameters(); long[] quality = new long[1]; quality[0] = 100; EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality); encoderParams.Param[0] = encoderParam; //获得包含有关内置图像编码解码器的信息的ImageCodecInfo 对象。 ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders(); ImageCodecInfo jpegICI = null; for (int x = 0; x < arrayICI.Length; x++) { if (arrayICI[x].FormatDescription.Equals("JPEG")) { jpegICI = arrayICI[x];//设置JPEG编码 break; } } if (jpegICI != null) { outBmp.Save(file, jpegICI, encoderParams); } else { outBmp.Save(file, thisFormat); } img.Dispose(); outBmp.Dispose(); System.IO.File.Delete(strTempFile); } #endregion #region 添加图片水印 ///<summary> /// 添加图片水印 /// </summary> /// <param name="png">水印图片</param> /// <param name="file">原文件</param> /// <param name="position">水印图片的位置 0居中、1左上角、2右上角、3左下角、4右下角</param> public void AttachPng(string png, string file) { if (string.IsNullOrEmpty(png)) return; if (!System.IO.File.Exists(png)) return; if (!System.IO.File.Exists(file)) return; System.IO.FileInfo oFile = new System.IO.FileInfo(file); string strTempFile = System.IO.Path.Combine(oFile.DirectoryName, Guid.NewGuid().ToString() + oFile.Extension); oFile.CopyTo(strTempFile); Image img = Image.FromFile(strTempFile); ImageFormat thisFormat = img.RawFormat; int nHeight = img.Height; int nWidth = img.Width; Bitmap outBmp = new Bitmap(nWidth, nHeight); Graphics g = Graphics.FromImage(outBmp); // 设置画布的描绘质量 g.CompositingQuality = CompositingQuality.HighQuality; g.SmoothingMode = SmoothingMode.HighQuality; g.InterpolationMode = InterpolationMode.HighQualityBicubic; g.DrawImage(img, new Rectangle(0, 0, nWidth, nHeight), 0, 0, nWidth, nHeight, GraphicsUnit.Pixel); img.Dispose(); img = Image.FromFile(png); //Bitmap bmpPng = new Bitmap(img); //ImageAttributes imageAttr = new ImageAttributes(); //Color bg = Color.Green; //imageAttr.SetColorKey(bg, bg); Size pngSize = NewSize(nWidth, nHeight, img); int nx = 0; int ny = 0; int padding = 10; if (SetPositionWater == 0) { nx = (nWidth - pngSize.Width) / 2; ny = (nHeight - pngSize.Height) / 2; } else if (SetPositionWater == 1) { nx = padding; ny = padding; } else if (SetPositionWater == 2) { nx = (nWidth - pngSize.Width) - padding; ny = padding; } else if (SetPositionWater == 3) { nx = padding; ny = (nHeight - pngSize.Height) - padding; } else { nx = (nWidth - pngSize.Width) - padding; ny = (nHeight - pngSize.Height) - padding; } g.DrawImage(img, new Rectangle(nx, ny, pngSize.Width, pngSize.Height), 0, 0, img.Width, img.Height, GraphicsUnit.Pixel); g.Dispose(); // 以下代码为保存图片时，设置压缩质量 EncoderParameters encoderParams = new EncoderParameters(); long[] quality = new long[1]; quality[0] = 100; EncoderParameter encoderParam = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, quality); encoderParams.Param[0] = encoderParam; //获得包含有关内置图像编码解码器的信息的ImageCodecInfo 对象。 ImageCodecInfo[] arrayICI = ImageCodecInfo.GetImageEncoders(); ImageCodecInfo jpegICI = null; for (int x = 0; x < arrayICI.Length; x++) { if (arrayICI[x].FormatDescription.Equals("JPEG")) { jpegICI = arrayICI[x];//设置JPEG编码 break; } } if (jpegICI != null) { outBmp.Save(file, jpegICI, encoderParams); } else { outBmp.Save(file, thisFormat); } img.Dispose(); outBmp.Dispose(); System.IO.File.Delete(strTempFile); } #endregion #region 得到指定mimeType的ImageCodecInfo /// <summary> /// 保存JPG时用 /// </summary> /// <param name="mimeType"> </param> /// <returns>得到指定mimeType的ImageCodecInfo </returns> private ImageCodecInfo GetCodecInfo(string mimeType) { ImageCodecInfo[] CodecInfo = ImageCodecInfo.GetImageEncoders(); foreach (ImageCodecInfo ici in CodecInfo) { if (ici.MimeType == mimeType) return ici; } return null; } #endregion #region 保存为JPEG格式，支持压缩质量选项 /// <summary> /// 保存为JPEG格式，支持压缩质量选项 /// </summary> /// <param name="SourceFile"></param> /// <param name="FileName"></param> /// <param name="Qty"></param> /// <returns></returns> public bool KiSaveAsJPEG(string SourceFile, string FileName, int Qty) { Bitmap bmp = new Bitmap(SourceFile); try { EncoderParameter p; EncoderParameters ps; ps = new EncoderParameters(1); p = new EncoderParameter(System.Drawing.Imaging.Encoder.Quality, Qty); ps.Param[0] = p; bmp.Save(FileName, GetCodecInfo("image/jpeg"), ps); bmp.Dispose(); return true; } catch { bmp.Dispose(); return false; } } #endregion #region 将图片压缩到指定大小 /// <summary> /// 将图片压缩到指定大小 /// </summary> /// <param name="FileName">待压缩图片</param> /// <param name="size">期望压缩后的尺寸</param> public void CompressPhoto(string FileName, int size) { if (!System.IO.File.Exists(FileName)) return; int nCount = 0; System.IO.FileInfo oFile = new System.IO.FileInfo(FileName); long nLen = oFile.Length; while (nLen > size * 1024 && nCount < 10) { string dir = oFile.Directory.FullName; string TempFile = System.IO.Path.Combine(dir, Guid.NewGuid().ToString() + "." + oFile.Extension); oFile.CopyTo(TempFile, true); KiSaveAsJPEG(TempFile, FileName, 70); try { System.IO.File.Delete(TempFile); } catch { } nCount++; oFile = new System.IO.FileInfo(FileName); nLen = oFile.Length; } } #endregion #endregion #region common method /// <summary> /// 图片上传错误编码 /// </summary> /// <param name="code"></param> /// <returns></returns> private string GetCodeMessage(int code) { var dic = new Dictionary<int, string>(){ {0,"系统配置错误"}, {1,"上传图片成功"}, {2,string.Format( "对不起，上传格式错误！请上传{0}格式图片",SetAllowFormat)}, {3,string.Format("超过文件上传大小,不得超过{0}M",SetAllowSize)}, {4,"未上传文件"}, {5,""}, {6,"缩略图长度和宽度配置错误"}, {7,"检测图片宽度限制"} }; return dic[code]; } private void TryError(ResponseMessage rm, int code) { rm.IsError = true; rm.Message = GetCodeMessage(code); } private void TryError(ResponseMessage rm, string message) { rm.IsError = true; rm.Message = message; } #endregion #region models public enum CutMode { /// <summary> /// 根据高宽剪切 /// </summary> CutWH = 1, /// <summary> /// 根据宽剪切 /// </summary> CutW = 2, /// <summary> /// 根据高剪切 /// </summary> CutH = 3, /// <summary> /// 缩放不剪裁 /// </summary> CutNo = 4 } public class ResponseMessage { /// <summary> /// 是否遇到错误 /// </summary> public bool IsError { get; set; } /// <summary> /// web路径 /// </summary> public string WebPath { get; set; } /// <summary> /// 文件物理路径 /// </summary> public string filePath { get; set; } /// <summary> /// 反回消息 /// </summary> public string Message { get; set; } /// <summary> /// 文件大小 /// </summary> public double Size { get; set; } /// <summary> /// 图片名 /// </summary> public string FileName { get; set; } /// <summary> /// 图片目录 /// </summary> public string Directory { get { if (WebPath == null) return null; return WebPath.Replace(FileName, ""); } } /// <summary> /// 缩略图路径 /// </summary> public string SmallPath(int index) { return string.Format("{0}{1}_{2}{3}", Directory, Path.GetFileNameWithoutExtension(FileName), index, Path.GetExtension(FileName)); } } #endregion } }