方法一: 002 /// asp.net上传图片并生成缩略图 003 /// </summary> 004 /// <param name="upImage">HtmlInputFile控件</param> 005 /// <param name="sSavePath">保存的路径,些为相对服务器路径的下的文件夹</param> 006 /// <param name="sThumbExtension">缩略图的thumb</param> 007 /// <param name="intThumbWidth">生成缩略图的宽度</param> 008 /// <param name="intThumbHeight">生成缩略图的高度</param> 009 /// <returns>缩略图名称</returns> 服务器端控件:fileupload public string UpLoadImage(FileUpload fileupload,string sSavePath,string sThumbExtension,int intThumbWidth,int intThumbHeight) public string UpLoadImage(HtmlInputFile upImage,string sSavePath,string sThumbExtension,int intThumbWidth,int intThumbHeight) { string sThumbFile =""; string sFilename =""; if(upImage.PostedFile !=null) { HttpPostedFile myFile = upImage.PostedFile; int nFileLen = myFile.ContentLength; if(nFileLen == 0) return"没有选择上传图片"; //获取upImage选择文件的扩展名 string extendName = System.IO.Path.GetExtension(myFile.FileName).ToLower(); //判断是否为图片格式 if(extendName !=".jpg"&& extendName !=".jpge"&& extendName !=".gif"&& extendName !=".bmp"&& extendName !=".png") return"图片格式不正确"; byte[] myData =new Byte[nFileLen]; myFile.InputStream.Read(myData,0 , nFileLen); sFilename = System.IO.Path.GetFileName(myFile.FileName); int file_append = 0; //检查当前文件夹下是否有同名图片,有则在文件名+ while(System.IO.File.Exists(System.Web.HttpContext.Current.Server.MapPath(sSavePath + sFilename))) { file_append++; sFilename = System.IO.Path.GetFileNameWithoutExtension(myFile.FileName) + file_append.ToString() + extendName; } System.IO.FileStream newFile =new System.IO.FileStream(System.Web.HttpContext.Current.Server.MapPath(sSavePath + sFilename), System.IO.FileMode.Create, System.IO.FileAccess.Write); newFile.Write(myData,0 , myData.Length); newFile.Close(); //以上为上传原图 try { //原图加载 using(System.Drawing.Image sourceImage = System.Drawing.Image.FromFile(System.Web.HttpContext.Current.Server.MapPath(sSavePath + sFilename))) { //原图宽度和高度 int width = sourceImage.Width; int height = sourceImage.Height; int smallWidth; int smallHeight; //获取第一张绘制图的大小,(比较 原图的宽/缩略图的宽 和 原图的高/缩略图的高) if(((decimal)width) / height <= ((decimal)intThumbWidth) / intThumbHeight) { smallWidth = intThumbWidth; smallHeight = intThumbWidth * height / width; } else { smallWidth = intThumbHeight * width / height; smallHeight = intThumbHeight; } //判断缩略图在当前文件夹下是否同名称文件存在 file_append =0 ; sThumbFile = sThumbExtension + System.IO.Path.GetFileNameWithoutExtension(myFile.FileName) + extendName; while(System.IO.File.Exists(System.Web.HttpContext.Current.Server.MapPath(sSavePath + sThumbFile))) { file_append++; sThumbFile = sThumbExtension + System.IO.Path.GetFileNameWithoutExtension(myFile.FileName) + file_append.ToString() + extendName; } //缩略图保存的绝对路径 string smallImagePath = System.Web.HttpContext.Current.Server.MapPath(sSavePath) + sThumbFile; //新建一个图板,以最小等比例压缩大小绘制原图 using(System.Drawing.Image bitmap =new System.Drawing.Bitmap(smallWidth, smallHeight)) { //绘制中间图 using(System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap)) { //高清,平滑 g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High; g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality; g.Clear(Color.Black); g.DrawImage( sourceImage, new System.Drawing.Rectangle(0, 0, smallWidth, smallHeight), new System.Drawing.Rectangle(0,0 , width, height), System.Drawing.GraphicsUnit.Pixel ); } //新建一个图板,以缩略图大小绘制中间图 using(System.Drawing.Image bitmap1 =new System.Drawing.Bitmap(intThumbWidth, intThumbHeight)) { //绘制缩略图 using(System.Drawing.Graphics g = System.Drawing.Graphics.FromImage(bitmap1)) { //高清,平滑 g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.High; g.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality; g.Clear(Color.Black); int lwidth = (smallWidth - intThumbWidth) /2 ; int bheight = (smallHeight - intThumbHeight) /2 ; g.DrawImage(bitmap,new Rectangle(0,0 , intThumbWidth, intThumbHeight), lwidth, bheight, intThumbWidth, intThumbHeight, GraphicsUnit.Pixel); g.Dispose(); bitmap.Save(smallImagePath, System.Drawing.Imaging.ImageFormat.Jpeg); } } } } } catch { //出错则删除 System.IO.File.Delete(System.Web.HttpContext.Current.Server.MapPath(sSavePath + sFilename)); return"图片格式不正确"; } //返回缩略图名称 return sThumbFile; } return"没有选择图片"; } 方法二: /// <summary> /// 图片上传,带缩略图自定义处理 /// </summary> /// <param name="fileupload">上传控件</param> /// <param name="pictureDirectoryAbsolutePath">站点下绝对目录路径 eg: "/pics/a/"</param> /// <param name="newPictureName">新命名图片(不带格式部分,格式维持原来的)</param> /// <param name="supportPictureType">eg: "|gif|jpg|png",如果为空,默认支持以上三种</param> /// <param name="message">返回消息</param> /// <param name="isCreateDefaultThumb">是否立即生成缩略图</param> public static bool PictrueUpload(FileUpload fileupload, string pictureDirectoryAbsolutePath, string newPictureName, string supportPictureType, out string pictureAbsolutePath, out string message, bool isCreateDefaultThumb, string thumbPhysicalFullPath, int thumbWidth, int thumbHeight, out string thumbAbsolutePath) { message = "图片上传成功"; pictureAbsolutePath = ""; thumbAbsolutePath = ""; #region 参数验证 string picturePhysicalFullPath = ""; if (string.IsNullOrEmpty(fileupload.FileName)) { message = "请选择待上传图片"; return false; ; } if (String.IsNullOrEmpty(pictureDirectoryAbsolutePath)) { message = "pictureDirectoryAbsolutePath参数不能为空"; return false; } if (String.IsNullOrEmpty(newPictureName)) { message = "newPictureName参数不能为空"; return false; } #endregion //存储目录创建 string pictureDirectoryPhysicalPath = HttpContext.Current.Server.MapPath(pictureDirectoryAbsolutePath); if (!Directory.Exists(pictureDirectoryPhysicalPath)) { Directory.CreateDirectory(pictureDirectoryPhysicalPath); } string fileName = fileupload.FileName.Trim(); string typeName = fileName.Substring(fileName.LastIndexOf('.') + 1).ToLower(); //上传图片格式验证 if (!PictureSupportFormatToValidate(typeName, supportPictureType, out message)) { return false; } //原始图片上传后的物理地址 picturePhysicalFullPath = pictureDirectoryPhysicalPath + newPictureName + "." + typeName; //原始图片上传 fileupload.SaveAs(picturePhysicalFullPath); //返回的图片绝对地址 pictureAbsolutePath = pictureDirectoryAbsolutePath + newPictureName + "." + typeName; #region 缩略图处理 //缩略图生成处理 if (isCreateDefaultThumb) { if (String.IsNullOrEmpty(thumbPhysicalFullPath)) { string thumbDirectoryPhysicalPath = String.Format("{0}thumb/", pictureDirectoryPhysicalPath); //缩略图目录创建 if (!Directory.Exists(thumbDirectoryPhysicalPath)) { Directory.CreateDirectory(thumbDirectoryPhysicalPath); } //缩略图存储地址 thumbPhysicalFullPath = String.Format("{0}{1}.jpg", thumbDirectoryPhysicalPath, newPictureName); } using (StreamReader sr = new StreamReader(picturePhysicalFullPath)) { CustomPictureManager.ThumbAsJPG(sr.BaseStream, thumbPhysicalFullPath, thumbWidth, thumbHeight); thumbAbsolutePath = pictureDirectoryAbsolutePath + "thumb/" + newPictureName + "." + typeName; } } #endregion 缩略图处理 return true; } |