GridView - Show headers on empty data source

Question

In C# how do I still show the headers of a gridview, even with the data source is empty.

I am not auto generating the columns as they are all predefined.

Currently what I am doing is the following.

Get a DataTable back from a stored procedure, then set the DataSource of the gridview, and then call DataBind().

This works fine when I have data, but when no rows are returned then I just get a blank spot where the grid should be.

Edit: Thanks all for the .NET 4+ property. I asked this back in the .NET 3.5 days. This is much easier now. :)

Answer 1

ASP.Net 4.0 added the boolean ShowHeaderWhenEmpty property.

http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.gridview.showheaderwhenempty.aspx

---

<asp:GridView runat="server" ID="GridView1" ShowHeaderWhenEmpty="true" AutoGenerateColumns="false">
    <Columns>
        <asp:BoundField HeaderText="First Name" DataField="FirstName" />
        <asp:BoundField HeaderText="Last Name" DataField="LastName" />
    </Columns>
</asp:GridView>

Note: the headers will not appear unless DataBind() is called with something other than null.

GridView1.DataSource = New List(Of String)
GridView1.DataBind()

Answer 2

After posting this I did come up with a way that works. However, I don't feel it is the best way to handle this. Any suggestions on a better one?

//Check to see if we get rows back, if we do just bind.

if (dtFunding.Rows.Count != 0)
{
    grdFunding.DataSource = dtFunding;
    grdFunding.DataBind();
}
else
{
  //Other wise add a emtpy "New Row" to the datatable and then hide it after binding.

     dtFunding.Rows.Add(dtFunding.NewRow());
     grdFunding.DataSource = dtFunding;
     grdFunding.DataBind();
     grdFunding.Rows[0].Visible = false;
}

Answer 3

I was just working through this problem, and none of these solutions would work for me. I couldn't use the EmptyDataTemplate property because I was creating my GridView dynamically with custom fields which provide filters in the headers. I couldn't use the example almny posted because I'm using ObjectDataSources instead of DataSet or DataTable. However, I found this answer posted on another StackOverflow question, which links to this elegant solution that I was able to make work for my particular situation. It involves overriding the CreateChildControls method of the GridView to create the same header row that would have been created had there been real data. I thought it worth posting here, where it's likely to be found by other people in a similar fix.