How to show tooltip on the view

How to show tooltip on the view.

For objects that inherit from GoNode, you can just set GoNode.ToolTipText.
For other objects, or if you want the tooltip to be generated dynamically, you can override GoObject.GetToolTip.

Oh, Sorry for my question.
I want to show tooltip when user move mouse over on view, not on the objects.
I know the manner which shows tooltip for nodes. But the GoView class hasn’t the GetToolTip method to override.

That’s a good idea for a new feature.
For now, you’ll need to override GoView.DoToolTipObject to call the base method and then check to see if the value of this.ToolTip.GetToolTip(this) is an empty string. If so, and if the current value is different from what you want, call ToolTip.SetToolTip.
We’ll add a GoView.ToolTipText string property so you can easily specify the default value for that GetToolTipText method.

Thanks, I added code as below, It showed tooltip. public override void DoToolTipObject(GoObject obj) {
if(obj==null)// for only view {
if(this.ToolTip.GetToolTip(this)!="test") {
this.ToolTip.SetToolTip(this, "test");
} else