Deselect the last selected row won't fire "SelectedIndexChanged" event.

[LamKhoa]

Hi,

When there is MultipleRowSelection = true & EnablePostBackOnRowClick = true, the event "SelectedIndexChanged" is fired everytime I check/uncheck row. That's great.  However, When I tried to uncheck the last selected row (so that now the grid has no row selected), the event "SelectedIndexChange" didn't fire.

I found a similiar post in here:
http://www.telerik.com/community/forums/aspnet-ajax/grid/radgrid-deselect-not-always-firing-selectedindexchanged.aspx

in which they suggested work-around using Javascript:

 

//JavaScript
function RowClick(sender, eventArgs) {

    sender.get_masterTableView().fireCommand("Select", eventArgs.get_itemIndexHierarchical());

}

//Code-Behind

PatientList_Grid.ClientSettings.ClientEvents.OnRowClick = "RowClick";

 

PatientList_Grid.ClientSettings.ClientEvents.OnRowDeselecting = "RowClick";

 

 

 

private void Grid_PatientList_SelectedIndexChanged(object sender, EventArgs e)
{
       RadGrid grd = sender as RadGrid;
       int SelectedCount = grd.SelectedItem.Count;
       lbl_DIsplay.Text = "Number of Item Selected: " + SelectedCount;
}

I did it as above and now the event "SelectedIndexChanged" does fire on deselecting last row. But, in the "SelectedIndexChanged" event, the grid show that it still have one item selected:

 

It still show up as 1, even though, you see, since the last selected has been deselected, it should be 0.

I'm using the latest version of Telerik AJAX control.

Thanks

Lamk.

[Wired_Nerve]

Any luck on this?

[Viktor Tachev]

Hello,

What you describe is expected behavior for the RadGrid. When an item is selected or deselected from the client the SelectedItems collection is updated. This collection is checked on the server prior firing the OnSelectedIndexChanged event. If SelectedItems collection has no elements the event is not fired. Thus the text of the label is not changed and you are seeing the last value.

Since you have set the EnablePostBackOnRowClick property to true, postback is performed after every click on a row. In this case you could use the PreRender method to check the number of elements in the SelectedItems collection. When the number reaches zero you could execute the logic you would like to implement.

Similar approach could be used if you select rows from the Grid with buttons. In this case your logic would be placed in a Button event.

Another approach would be to use server-side selection. This way the OnSelectedIndexChanged event will be fired also when deselecting the last selected row.

I hope this information is useful to you.

Regards,
Viktor Tachev
Telerik

[Wired_Nerve]

I have finally figured it out, thanks for the advice.