Asp.Net的FileUpload类实现上传文件实例

namespace CSFramework.BLL
{
   /// <summary>
   /// 支持上传的文件类型
   /// </summary>
   public enum UploadFileType
   {
      ArticleAttachment = 1,
      Image = 2,
      Video = 3,
      All = 4
   }
  
   /// <summary>
   /// 上传文件管理类
   /// </summary>
   public class CFileUpload
   {
      private FileUpload _fileUpload;
      private string _savePath;
      private string _LastUploadedFile = string.Empty;
      private bool _AutoGenFileName = false;
      private bool _AutoGenWatermark = false;
      public string LastUploadedFile { get { return _LastUploadedFile; } }
      private string _Error = "";
     
      private string PICTURE_FILE = "[.gif.png.jpeg.jpg]";
      private string ZIP_FILE = "[.zip.rar]";
      private string MUILT_MEDIA_FILE = "[.mpeg.mpg.fla.wma]";
     
      private int IMG_MAX_WIDTH = 700;//指定宽度
      private int IMG_MAX_HEIGHT = 0;//未指定高度
      private int MAX_SIZE_UPLOAD = 1024;//最大支持上传小于1MB的文件。
     
      /// <summary>
      /// 构造器
      /// </summary>
      /// <param name="fileUpload">Asp.net FileUpload对象</param>
      /// <param name="savePath">保存目录，不包含文件名</param>
      /// <param name="autoGenFileName">自动生成文件名</param>
      public CFileUpload(FileUpload fileUpload, string savePath, bool autoGenFileName, bool autoGenWatermark)
      {
         _savePath = savePath;
         _fileUpload = fileUpload;
         _AutoGenFileName = autoGenFileName;
         _AutoGenWatermark = autoGenWatermark;
      }
     
      /// <summary>
      /// 构造器
      /// </summary>
      /// <param name="fileUpload">Asp.net FileUpload对象</param>
      /// <param name="savePath">保存目录，不包含文件名</param>
      public CFileUpload(FileUpload fileUpload, string savePath)
      {
         _savePath = savePath;
         _fileUpload = fileUpload;
      }
     
      /// <summary>
      /// 上传RAR文件
      /// </summary>
      public bool UploadRARFile()
      {
         return DoUpload(ZIP_FILE);
      }
     
      /// <summary>
      /// 上传视频文件
      /// </summary>
      public bool UploadVideo()
      {
         return DoUpload(MUILT_MEDIA_FILE);
      }
     
      /// <summary>
      /// 上传图片文件
      /// </summary>
      public bool UploadImage()
      {
         return DoUpload(PICTURE_FILE);
      }
     
      public bool UploadImage(int maxWidth, int maxHeight)
      {
         this.IMG_MAX_WIDTH = maxWidth;
         this.IMG_MAX_HEIGHT = maxHeight;
         return DoUpload(PICTURE_FILE);
      }
     
      /// <summary>
      /// 上传任何支持的文件
      /// </summary>
      public bool UploadAnySupported()
      {
         return DoUpload(PICTURE_FILE ZIP_FILE MUILT_MEDIA_FILE);
      }
     
      /// <summary>
      /// 生成新的文件名
      /// </summary>
      private string GetNewFileName(string folder, string fileName)
      {
         if (_AutoGenFileName) //自动生成32位GUID文件名
         {
            string ext = System.IO.Path.GetExtension(fileName);
            string newfile = Guid.NewGuid().ToString().Replace("-", "") ext;
            return folder newfile;
         }
         else
         {
            if (System.IO.File.Exists(folder fileName))
            {
               string ext = System.IO.Path.GetExtension(fileName);
               string filebody = fileName.Replace(ext, "");
              
               int x = 1;
               while (true) //如果文件存在，生成尾部带(x)的文件
               {
                  string newfile = folder filebody "(" x.ToString() ")" ext;
                  if (!System.IO.File.Exists(newfile))
                  return folder filebody "(" x.ToString() ")" ext;
                  else
                  x ;
               }
            }
            else
            return folder fileName;
         }
      }
     
      /// <summary>
      /// 最大支持小于1MB的文件。
      /// </summary>
      private bool AllowMaxSize(int fileLength)
      {
         double kb = fileLength / 1024;
         return (int)kb < MAX_SIZE_UPLOAD;
      }
     
      private bool DoUpload(string allowedExtensions)
      {
         try
         {
            bool fileOK = false;
           
            if (!_fileUpload.HasFile) throw new Exception("没有文件！"); //上传控件中如果不包含文件，退出
           
            // 得到文件的后缀
            string fileExtension = System.IO.Path.GetExtension(_fileUpload.FileName).ToLower();
           
            // 看包含的文件是否是被允许的文件后缀
            fileOK = allowedExtensions.IndexOf(fileExtension) > 0;
            if (!fileOK) throw new Exception("不支持的文件格式！");
           
            //检查上传文件大小
            fileOK = AllowMaxSize(_fileUpload.FileBytes.Length);
            if (!fileOK) throw new Exception("图片文件不能大于" MAX_SIZE_UPLOAD.ToString() "KB！");
           
            try
            {
               // 文件另存在服务器指定目录下
               string savefile = GetNewFileName(_savePath, _fileUpload.FileName);
              
               if (IsUploadImage(fileExtension))//保存图片
               {
                  System.Drawing.Image output = CImageLibrary.FromBytes(_fileUpload.FileBytes);
                 
                  // 检查图片宽度/高度/大小
                  if (this.IMG_MAX_WIDTH != 0 && output.Width > this.IMG_MAX_WIDTH)
                  {
                     output = CImageLibrary.GetOutputSizeImage(output, this.IMG_MAX_WIDTH);
                  }
                 
                  Bitmap bmp = new Bitmap(output);
                 
                  this.CreateDir(Path.GetDirectoryName(savefile));
                 
                  bmp.Save(savefile, output.RawFormat);
                  bmp.Dispose();
                  output.Dispose();
                 
                  if (_AutoGenWatermark)
                  {
                     WatermarkImage genWatermark = new WatermarkImage();
                     genWatermark.DrawWords(savefile, AppConfig.Current.WatermarkMain,
                     AppConfig.Current.WatermarkDesc, float.Parse("0.2"));
                  }
               }
               else//其它任何文件
               {
                  this.CreateDir(Path.GetDirectoryName(savefile));
                 
                  _fileUpload.PostedFile.SaveAs(savefile);
               }
              
               _LastUploadedFile = savefile;
              
               return true;
            }
            catch (Exception ex)
            {
               throw new Exception("上传文件时发生未知错误！" ex.Message);
            }
         }
         catch (Exception ex)
         {
            _Error = ex.Message;
            return false;
         }
      }
     
      private void CreateDir(string dir)
      {
         if (Directory.Exists(dir) == false)
         Directory.CreateDirectory(dir);
      }
     
      private bool IsUploadImage(string fileExtension)
      {
         bool isImage = PICTURE_FILE.IndexOf(fileExtension) > 0;
         return isImage;
      }
   }
}