Hi Lim,
You can use the UpdateUI event of the barItem to validate the barItem before triggering the click event of the barItem.Note that this event will be triggered only when the UpdateUIMFCStyle property of the mainFrameBarManager is set to true.Please refer the sample attached.
Forum_47914.zip
Please let me know if you have any questions.Thanks for using Syncfusion products.
Regards,
K.Saradha Devi.