I have question. When I already set tooltip on TextBox it is showing when the mouse over at it. But when I click on a textbox to write, the Tooltip disappear.
Basically I want to show ToolTip when I click the TextBox - and disappear when I click another TextBox.
I think you can try the following workaround to achieve your goals.
I really don't know if there's an easier (or better) way to do what you want, but since it's so specific (you just want to close the previous tooltip when you click on the next textbox), I think you have to do something like this.