Prevent selected-index-changed-event for a custom-cell to fire until after all data has loaded.

[Oliver]

 

Hello,

I've created a custom cell in a radgridview so that I can in one column either display a RadDropDownListElement or a RadTextBoxControlElement depending on if the tag of the row has a datatable or not. If it has a datatable it will show the dropdown, otherwise it shows the textbox.

This I've done pretty much according to this tutorial.

https://docs.telerik.com/devtools/winforms/controls/gridview/cells/creating-custom-cells#custom-group-cell-example

 

However, my problem is that the selected index changed event on the dropdown is triggered too early, i.e. before all data has been loaded. Is there a way to get around this? I would like that the selected index changed event only kicked in if all the data of the form has been loaded. This I usually achieve by checking if a flag, e.g. 'IsInitiated', is true in the  beginning of the Sub. But cannot seem to reach such a flag from the custom cell class.

 

[Nadya | Tech Support Engineer]

Hello, Oliver,

Thank you for writing.

RadDropDownListElement offers ListElement property which has DataBindingComplete event. This event fires when the binding operation has finished. I can suggest using the DataBindingComplete event by raising a flag, e.g "IsInitiated" and later check the flag in the SelectedIndexChanged event. Please refer to the following example:

this.combo = new RadDropDownListElement();
this.combo.SelectedIndexChanged += Combo_SelectedIndexChanged;
this.combo.ListElement.DataBindingComplete += ListElement_DataBindingComplete;
//...

bool IsInitiated = false;
private void ListElement_DataBindingComplete(object sender, ListBindingCompleteEventArgs e)
{
   IsInitiated = true;
}

private void Combo_SelectedIndexChanged(object sender, Telerik.WinControls.UI.Data.PositionChangedEventArgs e)
{
    if (IsInitiated)
    {
        IsInitiated = false;
        return;
    }
    // TO DO
}

I hope this helps. If you have other questions, please let me know. 

Regards,
Nadya | Tech Support Engineer
Progress Telerik