How can i enlarge or narrow node

i just wan’t to enlagre or narrow view.

Are you referring to the width of an individual Node, or the width of some GraphObject within a Node? Set the GraphObject.width property to be a real, non-negative number, on the GraphObject whose width you want to control.

It would help if you had a screenshot of your node plus an outline of the structure of the node, i.e. its visual tree.

Thanks.Now i can use mouse wheel enlarge or narrow view. but i want to trigger event with buttons. can you give me some advices?

You can have your buttons call:

myDiagram.commandHandler.increaseZoom();

myDiagram.commandHandler.decreaseZoom();

myDiagram.commandHandler.resetZoom();

See also: http://gojs.net/latest/intro/commands.html

Nice.A good solution. Thank you.