ASP.NET 文件操作：上传与下载指南

1.上传文件，存入数据库。并利用打开新页面的形式下载。

 <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" Width="371px"  _disibledevent="GridView1_RowCommand">
                <Columns>
                    <asp:BoundField  DataField="id" HeaderText="编号" />
                    <asp:BoundField DataField="type" HeaderText="文件类型" />
                    <asp:TemplateField HeaderText="下载">
                        <ItemTemplate>
                            <asp:LinkButton ID="LinkButton1" runat="server" CommandName="dnl" CommandArgument="id"><%# DataBinder.Eval(Container.DataItem,"id") %></asp:LinkButton>
                       <a href="DownLoad.aspx?id=<%# DataBinder.Eval(Container.DataItem,"id") %>" target="_blank">DownLoad</a>
                        </ItemTemplate>
                    </asp:TemplateField>
                </Columns>
            </asp:GridView>

protected void btnload_Click(object sender, EventArgs e)
    {//上传文件，并保存到数据库
        Stream filedatastream = this.FileUpload.PostedFile.InputStream;

        HttpPostedFile file = FileUpload.PostedFile;
        int filelenth = FileUpload.PostedFile.ContentLength;

        byte[] filedata = new byte[filelenth];
        filedatastream.Read(filedata, 0, filelenth);

        string filetype = Path.GetExtension(FileUpload.PostedFile.FileName);

        SqlConnection conn = new SqlConnection(DB.connstrings);
        conn.Open();
        SqlCommand cmd = new SqlCommand("insert into myfile(files,type) values(@files,@type)", conn);