问题
In the continuous search for a solution to my question: Append a control above/upper to the Shell App bar without altering it
As it seems the hamburger button is part of the Toolbar, I was investigating this latter, but I cannot find where/how shellcontent_toolbar and main_toolbar resources are defined?
回答1:
You could look at ShellToolbarTracker,in this source codes,you could see the hamburger button (DrawerArrowDrawable icon ) is set in the toolbar.
来源：https://stackoverflow.com/questions/64505934/where-how-shellcontent-toolbar-and-main-toolbar-resources-are-defined-in-the-sou