<div>

            <input id="fileUpload" type="file" runat="server" />

            <input id="btnFile" type="button" value="上传" runat="server" />

            <asp:Button ID="Button1" runat="server" Text="点击下载" OnClick="Button1_Click1" />

            <br />

            <br />

            <img alt="" src="<%=url%>" width="100" height="100" id="imgShow" />

        </div>

protected void Page_Load(object sender, EventArgs e)

        {

            btnFile.ServerClick += GetFile;

        }

        public string url = "";

        public void GetFile(object sender, EventArgs e)

        {

            String[] Extensions = { ".gif", ".png", ".jpeg", ".jpg", ".bmp" };

            if (!Directory.Exists(Server.MapPath(@"/word/")))

            {

                Directory.CreateDirectory(Server.MapPath(@"/word/"));

            }

            fileUpload.PostedFile.SaveAs(Server.MapPath(@"/word/") + fileUpload.Value);

            if (Extensions.Contains("." + fileUpload.Value.Split('.')[]))

            {

                url = @"/word/" + fileUpload.Value;

            }

        }

        protected void Button1_Click1(object sender, EventArgs e)

        {

            string strFileName = "典型病例.rtf";

            Response.ContentType = "application/x-zip-compressed";

            //Response.ContentEncoding = System.Text.Encoding.GetEncoding("gb2312");

            string filename = @"E:\个人练习\MvcDemo\WebTest\word20160620140544\" + strFileName;

            //为路径

            Response.AddHeader("Content-Disposition", "attachment;filename=" + Server.UrlPathEncode(strFileName));

            //Server.UrlPathEncode(); 解决文件名的乱码问题.

            Response.TransmitFile(filename);

        }