Based on my discussion with the developer, the FreezePane must be enabled or disabled in client side event handler. I am still in the process of simulating the scenario in my environment. I will inform you of any discovery I made.

So how would that work in my example?

Add a dynamic script somehow in PreRender to do that on the client side?

After further testing using the sample code in this thread. You could disable the ColumnFreeezing during page load event. Here is the snippet, only disable the ColumnFreezing if the SelectedValue is C:

protected void Page_Load(object sender, EventArgs e)
{
    if(!Page.IsPostBack)
    {
        ddlChoiceA.Items.Add(new System.Web.UI.WebControls.ListItem("A: all columns", "A"));
		ddlChoiceA.Items.Add(new System.Web.UI.WebControls.ListItem("B: some hidden columns (16-19, 21-22)", "B"));
        ddlChoiceA.Items.Add(new System.Web.UI.WebControls.ListItem("C: no data", "C"));
	}

    if (ddlChoiceA.SelectedValue == "C")
        grdResult.LayoutSettings.AllowColumnFreezing = ColumnFreezing.No;
}

Hi Glenn,

Thanks for your idea. I didn't try it, because I think it cannot work by design - tell me if I'm wrong. What you are doing here is to enable/disable freezing in Page_Load, depending on whether the filter is set to a value that doesn't return data.

We don't know if there is data available or not, just by looking at the filter selection. In this hardcoded sample it might work, but what you are doing here would mean to query the database in Page_Load to see if there is data available or not. Is it that what you intended here?

For me that would mean we have two database requests: one in Page_Load, the other one in grid_InitializeDataSource. One must be enough. Did you want to move this all to the Page_Load event? If yes, then that part is missing. Or did I misunderstand anything?

Any other ideas?

Regards,

Eric

Hii Glenn,

Thanks for clarification. Here some comments from my side:

Two database calls is not an option for two reasons:

• It would be slow. If you make two different calls, the first one only calling a COUNT, there would probably be no big difference, except the call overhead and the actual database counting.
• Bad design, risking a crash. If the data changes between the two calls, the result would be undefined or completely wrong.

Yes, calling the db in OnLoad and caching it somehow, like in a member variable, would be an option. I will consider this. Or remove the freezeing altogether.

But why is PreRender too late? I think this is a design flaw in WebGrid. Before the PreRender event, no data should get rendered to the client. And enabling/disabling column freezing, which can also be done on the client-side, is clearly a rendering issue. Don't you agree with this?