LoadOnDemand ComboBox in ToolTip error

[Steve White]

I have a TreeView with each node set as the Target for a ToolTipManager. In the ToolTip I dynamically inject a UserControl. The UserControl contains a ComboBox wired up to ItemsRequested.

When I try to open the ComboBox to run the ItemsRequested code I get an alert:

"The target 'controlid' for the callback could not be found or did not implement ICallBackEventHandler"

Could you please post a small demo project that illustrates a dynamic UserControl with a LoadOnDemand ComboBox inside a ToolTip generated from a TreeView node mouseover.

thanks,

Steve

[Steve White]

I'm loading a usercontrol into the tooltip with a ComboBox in it. I want ItemsRequested to fire when I try to select anything in the ComboBox, but I can't get any server events to work.

Can you give me some guidance on how to do this please?

thanks,

Steve

[Simon]

Hello Steve White,

This happens because the ComboBox does not exist in the Page's Control Tree when the client-side object initiates the Items request.

So, in order to fix this the server-side ComboBox object must be added on the page during such requests on the same place in the Control Tree. Additionally, the z-index of the ComboBox's drop down must be increased, so that it appears above the Tooltip.

Please see the attached files as a reference to the needed modifications to the Page's code.

All the best,
Simon
the Telerik team

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