上传下载(上传图片 上传文件 下载文件)

1.上传图片 上传文件

private void UpImg()    {        if (this.FileUpload1.HasFile)//上传控件命是否有文件        {            string path = Server.MapPath("~/Images/");//你要保存的目录            if (!Directory.Exists(path))    //判断目录是否存在不存在创建目录                Directory.CreateDirectory(path);            string name = FileUpload1.FileName;  //获取上传的文件名称            String ext = Path.GetExtension(FileUpload1.FileName).ToLower();  //获取上传文件的后缀名            String[] allowedExtensions = {".txt", ".gif", ".png", ".bmp", ".jpg" }; //允许的扩展名            bool fileOK = false;            for (int i = 0; i < allowedExtensions.Length; i++)//判断是否是图片            {                if (ext == allowedExtensions[i])                {                    fileOK = true;                    break;                }            }            if (fileOK)//是图片上传            {                string newName = Guid.NewGuid() + ext; //重命名，防止重名文件                FileUpload1.SaveAs(path + newName);   //保存到服务器上了。              }        }    }

上传方法2

private void FileUpload()    {        try        {            if (FileUpload1.PostedFile.FileName.Length == 0)            {                Response.Write("<script>alert(\"上传路径不能为空！\");</script>");                return;            }            string filename = this.FileUpload1.PostedFile.FileName.Substring(this.FileUpload1.PostedFile.FileName.LastIndexOf("\\") + 1);            string houzhui = FileUpload1.PostedFile.FileName.Substring(this.FileUpload1.PostedFile.FileName.LastIndexOf(".") + 1);            if (houzhui == "gif" || houzhui == "jpg" || houzhui == "bmp")            {                FileUpload1.PostedFile.SaveAs(Server.MapPath("image/" + filename));                Response.Write("<script>alert(\"上传文件成功！\");</script>");            }            else            {                Response.Write("<script>alert(\"上传文件必须是gif,jpg,bmp格式！\");</script>");                return;            }        }        catch (Exception ex)        {            Response.Write("<script>alert(\"" + ex.Message + "\");</script>");        }    }

多个文件上传

string f_name, f_size, f_type;        HttpFileCollection hfc = Request.Files;//获取客户端文件集合        for (int i = 0; i < hfc.Count; i++)        {            HttpPostedFile hpf = hfc[i];            f_name = hpf.FileName;//名称            f_size = hpf.ContentLength.ToString();//大小字节            f_type = hpf.ContentType;//mime类型            string filename = System.IO.Path.GetFileName(f_name);            string path = @"F:/ZMProject/Demo/Demo/WebDemo/Images/" + filename;            hpf.SaveAs(path);            Response.Write("<br>" + f_name + "<br>" + f_size + "<br>" + f_type);        }

2.下载文件

/// <summary>     /// 下载指定的文件     /// </summary>     /// <param name="FileName">文件在服务器上的路径</param>     public static void FileDownload(string FileName)    {        String FullFileName = System.Web.HttpContext.Current.Server.MapPath(FileName);        FileInfo DownloadFile = new FileInfo(FullFileName);        System.Web.HttpContext.Current.Response.Clear();        System.Web.HttpContext.Current.Response.ClearHeaders();        System.Web.HttpContext.Current.Response.Buffer = false;        System.Web.HttpContext.Current.Response.ContentType = "application/octet-stream";        System.Web.HttpContext.Current.Response.AppendHeader("Content-Disposition", "attachment;filename=" + System.Web.HttpUtility.UrlEncode(DownloadFile.FullName, System.Text.Encoding.UTF8));        System.Web.HttpContext.Current.Response.AppendHeader("Content-Length", DownloadFile.Length.ToString());        System.Web.HttpContext.Current.Response.WriteFile(DownloadFile.FullName);        System.Web.HttpContext.Current.Response.Flush();        System.Web.HttpContext.Current.Response.End();    }