Can't Find Hyperlink of Cell during Gridview RowDatabound

Question

I have a gridview that lists rows of information from SQL. If the late column is set to 1 it should display the text of the row in red. This works, however the hyperlink text will not be displayed in red. So I'm trying to a) change the forecolor of the hyperlink element or b) apply a class to the element. When I try to retrieve the hyperlink it does not get it. When I retrieve a label it seems to work fine.

ASP

<asp:TemplateField HeaderText="Project">
      <ItemTemplate>
           <a id="hlProject" href="VpnDetails.aspx?Project=<%# Eval("id") %>"><%# Eval("project") %></a>
       </ItemTemplate>
 </asp:TemplateField>
<asp:TemplateField HeaderText="Last Update">
       <ItemTemplate>
           <asp:Label ID="lblLastUpdate" runat="server" Text='<%#Eval("diff") %>'></asp:Label>
       </ItemTemplate>
  </asp:TemplateField>

C#

protected void gvLastIp_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        if (e.Row.RowType == DataControlRowType.DataRow)
        {
            //Adds the tooltip to the last update label
            Label lblLastUpdate = e.Row.FindControl("lblLastUpdate") as Label;
            DateTime activeSince = Convert.ToDateTime(DataBinder.Eval(e.Row.DataItem, "begindate"));
            DateTime lastupdate = Convert.ToDateTime(DataBinder.Eval(e.Row.DataItem, "lastupdate"));
            lblLastUpdate.ToolTip = "Active Since " + activeSince.ToString("MMMM d yyyy HH:mm") + " - Last Update " + lastupdate.ToString("MMMM d yyyy HH:mm");

            if (Convert.ToString(DataBinder.Eval(e.Row.DataItem, "late")) == "1")
            {//if the row is late it should be red
                e.Row.Font.Bold = true;
                e.Row.ForeColor = System.Drawing.Color.Red;

                HyperLink hlProject = new HyperLink();
                try
                {
                    hlProject = (HyperLink)e.Row.FindControl("hlProject");
                    hlProject.Attributes.Add("class", "late");
                    hlProject.ForeColor = System.Drawing.Color.Red;
                }
                catch (Exception e1)
                {
                    lblError.Text = e1.Message;
                }
            }
        }

So I need to know why it works for the label and not for the hyperlink. I also need a solution for the hyperlink.

You are missing `runat="server"` on the hyperlink. It needs to be a server side control to be able to use it on the server. — j.f., Sep 25 '14 at 14:55
If you include a runat="server" it states that "The server tag is not well formed.", it does that when you do the <# Eval()%>... I'll see if I can do a work around for the href then. — Charles Rutherford, Sep 25 '14 at 15:01
@CharlesRutherford, like Rex stated, it may be easier to use an ASP.NET hyperlink. `` — j.f., Sep 25 '14 at 15:14
@Rex you are correct for the ASP.NET hyperlink. The control couldnt find what I was using even if the runat=server was there but it is able to find the ASP.NET hyperlink. — Charles Rutherford, Sep 25 '14 at 15:23

score 2 · Accepted Answer · answered Sep 25 '14 at 15:42

You can't find your hyperlink on the server because it is not a server side control. You need to add runat="server" to do just that. Note the change to the href to make it valid.

<a id="hlProject" runat="server" href='<%# Eval("id", "VpnDetails.aspx?Project={0}") %>'><%# Eval("project") %></a>

You would then be able to grab it server side by finding it within your row.

using System.Web.UI.HtmlControls;

protected void gvLastIp_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        HtmlAnchor hlProject = (HtmlAnchor)e.Row.FindControl("hlProject");
    }
}

Alternatively, you could create and use an ASP.NET Hyperlink control. This is a little more flexible/useful on the server side.

<asp:HyperLink ID="hlProject" runat="server"
  NavigateUrl='<%# Eval("id", "VpnDetails.aspx?Project={0}") %>'
  Text='<%# Eval("project") %>'>
</asp:HyperLink>

protected void gvLastIp_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if (e.Row.RowType == DataControlRowType.DataRow)
    {
        HyperLink hlProject = (HyperLink)e.Row.FindControl("hlProject");
    }
}

You are right about not putting the runat server. The second mistake was using hyperlink and not htmlanchor. Thanks — Charles Rutherford, Sep 25 '14 at 15:45

score -1 · Answer 2 · answered Sep 25 '14 at 15:00

-1

protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
{
    if(e.Row.RowType == DataControlRowType.DataRow)
    {
        HyperLink myHyperLink = e.Row.FindControl("myHyperLinkID") as HyperLink;
    }
}

This should work.

answered Sep 25 '14 at 15:00

mrsrizan

301
1
8

This is essentially what OP is doing now. How does this help? – j.f. Sep 25 '14 at 15:17
@j.f is right. I already had that in my code. Maybe not 100% the same way but the same functionality was there. – Charles Rutherford Sep 25 '14 at 15:46

Can't Find Hyperlink of Cell during Gridview RowDatabound

2 Answers2