Can not download file from project directory (asp.net)

Question

There is my problem. I'm trying to download file from asp.net project directory. File is in "Date" directory. I have done WebForm1.aspx page with GridView that display files in Date directory. All files is displaying like a link.
There is my code bottom.

protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
{
    if(e.CommandName == "Download")
    {
        Response.Clear();
        Response.ContentType = "text/plain";
        Response.AppendHeader("content-disposition", "filename" + e.CommandArgument);
        Response.TransmitFile(Server.MapPath("~/Data/") + e.CommandArgument);            
        Response.End();
    }
}

I go through the link with file. After that my browser offer to download not my file but the file of all page (WebForm1.aspx) Help me solve this problem. What have I done incorrect?

image with problem

Answer 1

您的处理标头很奇怪（没有attachment ，缺少= ），更改为：

Response.AppendHeader("content-disposition", "attachment; filename=" + e.CommandArgument);