Question

I have a GridView containing records from a table which can be deleted or updated. If you want to edit a row, it should display the update and cancel buttons so that you can keep or cancel the current edit (I hide update and cancel as default). I am using the following asp for the button column of the GridView:

<asp:TemplateField visible ="true" >
<HeaderTemplate>
    <div id = "header">Maintain</div>
</HeaderTemplate>
<ItemTemplate>
        <asp:Button ID="btnDelete"  Text="Delete"   Runat="Server" CommandName="Delete" Visible="true"  CommandArgument='<%#Eval("UNIQUEID")%>'/>
        <asp:Button ID="btnEdit"    Text="Edit"     Runat="Server" CommandName="Edit"   Visible="true"  CommandArgument='<%#Eval("UNIQUEID")%>'/>
        <asp:Button ID="btnCancel"  Text="Cancel"   Runat="Server" CommandName="Cancel" Visible="false" CommandArgument='<%#Eval("UNIQUEID")%>'/>
        <asp:Button ID="btnUpdate"  Text="Update"   Runat="Server" CommandName="Update" Visible="false" CommandArgument='<%#Eval("UNIQUEID")%>'/>
</ItemTemplate>
</asp:TemplateField>

I use the following code to handle the command that has been pressed:

protected void grdResults_RowCommand(object sender, GridViewCommandEventArgs e)
{
    int pk;
    if (e.CommandName == "Edit")
    {
        int index = 0;
        foreach (result r in allSearchResults)  //get the row index with the grid
        {
            if (r.UniqueID == Convert.ToInt32(e.CommandArgument))
                break;
            index++;
        }
        ((Button)(grdResults.Rows[index].FindControl("btnUpdate"))).Visible = true;
        ((Button)(grdResults.Rows[index].FindControl("btnCancel"))).Visible = true;
    }
    if (e.CommandName == "Delete")
    {
        _presenter.modifySearchResults(Convert.ToInt32(e.CommandArgument));  //delete the item from the search results
    }
    if (e.CommandName == "Update")
    {
        //TODO update the search results with the edited text
    }
    if (e.CommandName == "Cancel")
    {
        //TODO cancel the current edit
    }
}

For some reason however, when I click edit, it does not show the update button. When I step through the code it does find the btnUpdate control and changes its visibility correctly but does not show on the screen.

Answer 1

Probably it is in the wrong place in ASP.NET lifecycle. Try moving showing/hiding buttons to PreRender