文件的上传、下载及删除方法

#region 文件的上传、下载及删除     //文件的上传方法     if (fdAppImages.HasFile)            {    /***重命名文件，防止重复***/                string fn = Guid.NewGuid().ToString() + fdAppImages.FileName.Substring(fdAppImages.FileName.LastIndexOf("."));               // string fn = System.IO.Path.GetFileName(fdAppImages.PostedFile.FileName);                int index = fn.LastIndexOf(".");                string lastName = fn.Substring(index, fn.Length - index);                if (lastName != ".jpg" && lastName != ".gif" && lastName != ".png")                {                    Alert("只能上传jpg|gif|png的图片文件！");                    return;                } /***获取文件存放的虚拟路径***/                string imageUploadUrl = ConfigurationManager.AppSettings["PreviewImages"].ToString(); /***获取文件存放的物理路径***/                string imageUploadPath = Server.MapPath(imageUploadUrl);                string imageUrl = imageUploadUrl + "/" + fn;                 /***判断文件是否已存在***/                if (!File.Exists(imageUploadPath))                {                    Directory.CreateDirectory(imageUploadPath);                }                imageUploadPath = Server.MapPath(imageUploadUrl) + "\\" + fn;                 /***将上载的文件内容保存到web服务器指定的路径***/                this.fdAppImages.SaveAs(imageUploadPath);            }//删除文件方法（存放文件对应的物理路径）string path = string.Empty;                FileInfo fi = null;                string[] arr = strStr.ToString().Split(',');                foreach (string item in arr)                {                    path = Page.Server.MapPath(item);                    fi = new FileInfo(path);                   /***判断文件是否已存在***/                    if (fi.Exists)                    {                        fi.Delete();                    }                }//文件的下载方法 protected void dataRepeater_ItemDataBound(object sender, RepeaterItemEventArgs e)     {   HyperLink hlDownLoad = e.Item.FindControl("hlDownLoad") as HyperLink;           if (string.IsNullOrEmpty((e.Item.DataItem as DataRowView)["ApkUrl"].ToString()))            {                hlDownLoad.Visible = false;            }            else            {                hlDownLoad.NavigateUrl = GetWebSourcePath((e.Item.DataItem as DataRowView)["ApkUrl"].ToString());            }     } /// <summary>    /// 获取资源相对路径对应的网络绝对地址    /// </summary>    /// <param name="url">资源的相对路径</param>    /// <returns>网络绝对地址</returns>    protected string GetWebSourcePath(string url)    {        return GetSiteRootURL() + url.Replace("~", "");    }    /// <summary>    /// 取得网站的根目录的URL,包括虚拟目录    /// </summary>    /// <returns>如：https：//www.189.cn/web </returns>    protected string GetSiteRootURL()    {        string siteRootUrl = string.Empty;        HttpContext httpCurrent = HttpContext.Current;        HttpRequest httpRe;        if (httpCurrent != null)        {            httpRe = httpCurrent.Request;            string urlAuthority = httpRe.Url.GetLeftPart(UriPartial.Authority);            if (httpRe.ApplicationPath == null || httpRe.ApplicationPath == "/")//如果是在web站点            {                siteRootUrl = urlAuthority;            }            else//如果是在web站点的虚拟子目录下            {                siteRootUrl = urlAuthority + httpRe.ApplicationPath;            }        }        return siteRootUrl;    }#endregion