[android] How to get Activity's content view?

What method should I call to know if an Activity has its contentView (once the method setContentView() has been called)?

The best option I found and the less intrusive, is to set a tag param in your xml, like

PHONE XML LAYOUT

<android.support.v4.view.ViewPager xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:tag="phone"/>

TABLET XML LAYOUT

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/pager"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:tag="tablet">

    ...

</RelativeLayout>

and then call this in your activity class:

View viewPager = findViewById(R.id.pager);
Log.d(getClass().getSimpleName(), String.valueOf(viewPager.getTag()));

Hope it works for u.

If you are using Kotlin

    this.findViewById<View>(android.R.id.content)
                         .rootView
                         .setBackgroundColor(ContextCompat.getColor(this, R.color.black))

You may want to try View.getRootView().

You can also override onContentChanged() which is among others fired when setContentView() has been called.

You can get the view Back if you put an ID to your Layout.

<RelativeLayout
    android:id="@+id/my_relative_layout_id"

And call it from findViewById ...

How about

View view = Activity.getCurrentFocus();

There is no "isContentViewSet" method. You may put some dummy requestWindowFeature call into try/catch block before setContentView like this:

try {
  requestWindowFeature(Window.FEATURE_CONTEXT_MENU);
  setContentView(...)
} catch (AndroidRuntimeException e) {
  // do smth or nothing
}

If content view was already set, requestWindowFeature will throw an exception.