Android Studio 1.4-解释activity_main.xml和content_main.xml

Question

I just updated my Android Studio to 1.4, and I'm a bit confused about activity_main.xml and the other xml file content_main.xml.

I have this app that programatically generates xml. Everything is fine, except I don't have the action bar.

My onCreate is like this:

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    getSupportActionBar().setDisplayHomeAsUpEnabled(true);

    ...
   // set layout programatically


  setContentView(myCustomXML);

How do I get the action bar? There must be some very simple solution to this.

Answer 1

Many design components that were introduced with Android Lollipop version. The main problem you are probably not awared right now is the Toolbar Widget .

As you can see in your AndroidManifest.xml , for MainActivity there is "...NoActionBar" theme used. Therefor there is no default actionbar placed on top od activity_main layout. Instead of that there is android.support.v7.widget.Toolbar component used and it is part of content XML.

Notice, that Toolbar is part of activity_main.xml and probably not part of your MyCustomXML .

If this is not your problem, then you probably just need to setSupportActionBar(android.support.v7.widget.Toolbar) or setActionBar(android.widget.Toolbar) .

After you have set action bar from your layout.xml you can get it via getSupportActionBar() / getActionBar() methods.

Hopefuly, this is what you are looking for, because your question is not 100% clear

Edit: Do not use setContentView() twice and do not expect anything to work if you work with views before setContentView() method is called (Toolbar is also view)