Try to handle the ItemInplaceEditEnding event and check the NewText property of the event argument. If you compare the value of this property with the current value of the HeaderText property of the in-place edited item (you can obtain a reference to the in-place edited item from the event arguments as well), you can determine whether the item text has changed during the in-place editing. The following code shows a sample handler of the ItemInplaceEditEnding event:

private void calendar_ItemInplaceEditEnding(
    object sender, ItemEditConfirmEventArgs e)
{
    if (e.Item.HeaderText != e.NewText)
    {
	  // The item text has been changed during in-place editing
    }
} 

Meppy