文件处理

（一）删除文件

using System.IO;

filepath = Server.MapPath("\\")+name;                    
File.Delete(filepath);

（二）上传文件

  public UploadFileInfo UploadFile( HtmlInputFile source, string saveParentUrl,string strFileName)
      {
         UploadFileInfo uploadFileInfo = new UploadFileInfo();
            //获得资源保存的总目录 
           string strAbsoluteDirectory = System.Configuration.ConfigurationSettings.AppSettings["UploadFileUrl"];              uploadFileInfo.AbsolutePath = System.Web.HttpContext.Current.Server.MapPath( strAbsoluteDirectory );
            //资源保存的最终目录         
         uploadFileInfo.AbsolutePath += saveParentUrl; //实际用
          uploadFileInfo.RelativePath = strAbsoluteDirectory + saveParentUrl;
         string extension = CommonUrl.GetFileExtension( source.PostedFile.FileName );
         
         uploadFileInfo.Extension = extension;
         uploadFileInfo.FileName =  strFileName + extension.ToUpper(); 
         uploadFileInfo.Size = source.PostedFile.ContentLength;
         if( !System.IO.Directory.Exists( uploadFileInfo.AbsolutePath ) )
         {
            System.IO.Directory.CreateDirectory( uploadFileInfo.AbsolutePath );
         } 
         if( System.IO.File.Exists( uploadFileInfo.AbsolutePath + uploadFileInfo.FileName ) )
         {
            System.IO.File.Delete( uploadFileInfo.AbsolutePath + uploadFileInfo.FileName );
         }
         source.PostedFile.SaveAs( uploadFileInfo.AbsolutePath + uploadFileInfo.FileName );          
         return uploadFileInfo;
      }