关于文件的上传及管理（asp.net）

 #region 上传文件按钮事件
    protected void btn_Upload_Click(object sender, EventArgs e)
    {
        //判断用户是否选择了文件
        if (FileUpload.HasFile)
        {
            //调用自定义方法判断文件类型否符合
            if (IsAllowableFileType())
            {
                //判断文件大小是否符合
                if (IsAllowableFileSize())
                {
                    //从web.config中读取上传路径
                    string strFileUploadPath = ConfigurationManager.AppSettings["FileUplodePath"].ToString();
                    //从UploadFile控件中读取文件名
                    string strFileName = FileUpload.FileName;
                    //组合成物理路径
                    string strFilePhysicalPath = Server.MapPath(strFileUploadPath + "/") + strFileName;
                    //判断文件是否存在
                    if(!File.Exists(strFilePhysicalPath))
                    {
                        //保存文件
                        FileUpload.SaveAs(strFilePhysicalPath);
                        //更新列表框
                        lb_FileList.Items.Add(strFileName);
                        //更新文件夹信息
                        InitFolderInfo();
                        ShowMessageBox("上传成功!");
                    }
                    else
                    {
                        ShowMessageBox("文件已经存在!");
                    }
                }
                else
                {
                    ShowMessageBox("文件大小不符合要求!");
                }
            }
            else
            {
                ShowMessageBox("类型不匹配");
            }
        }
    }