Asp.net DataGrid file structure and binding

I am using DataGrid:

<asp:DataGrid runat="server" ID="articleList" UseAccessibleHeader="true" AutoGenerateColumns="false" AlternatingItemStyle-BackColor="#EEEEEE" HeaderText="File Name">
    <Columns>
        <asp:HyperLinkColumn DataNavigateUrlField="DirectoryName" DataTextField="Name" HeaderText="File Name" />
        <asp:BoundColumn DataField="LastWriteTime" HeaderText="Modified" ItemStyle-HorizontalAlign="Center" DataFormatString="{0:f}" />
        <asp:BoundColumn DataField="Length" HeaderText="Size" ItemStyle-HorizontalAlign="Right" DataFormatString="{0:#,### bytes}" />
        <asp:BoundColumn DataField="Extension" HeaderText="Type" ItemStyle-HorizontalAlign="Left" />
    </Columns>
</asp:DataGrid>

Here is my code page:

protected void Page_Load(object sender, EventArgs e)
{
    DirectoryInfo dirInfo = new DirectoryInfo(Server.MapPath("examfilemanager"));

    articleList.DataSource = dirInfo.GetFiles();
    articleList.DataBind();
}

Files inside this directory:

01.jpg
02.jpg
MyDoc.doc

I am trying to provide a direct link for a click to click and load it. It seems that the only links I can get is the name "01.jpg", which is inside the document manager.

The Name property of the file information properties returns only the name. (01.jpg)

Link href to link 01.jpg, I need it to be examfilemanager/01.jpg, how can I make it possible?