How do I add an action to the Toolbar?

You must declare your action in your layer.xml file. Like this:

<folder name="Toolbars">
   <folder name="Build">
         <file name="org-mymodule-MyAction.instance"/>
</folder></folder>

See also:

• How do I add an action to a file of a given mime-type?
• How do I add an action to a folder?
• How do I add an action to the text-editor popup menu?
• How do I add an action to the NetBeans menu bar?
• How do I add an action to my custom node?