Android工具栏，如何隐藏和显示片段

Question

I have a ToolBar (android.support.v7.widget.Toolbar) which has 2 clickble icons which are meant to display their own views.

I thought that, the main activity which hosted the ToolBar, and held the onCreateOptionsMenu(), onOptionItemSelected() etc methods, should then have 2 fragments, corresponding to the icons. So when I click on one icon, and then to another, the relevant fragments should be hidden/shown. Is this the correct way to go forward? Or am I meant to use intents?

I also thought of using a FragmentStatePager adapter with a ViewPager but I am unsure if that is a possibility, since this is a ToolBar and not a seperate sliding mechanism to travel from Fragment A -> Fragment B and vice versa.

Answer 1

Add a FrameLayout in your activity:

<FrameLayout
    android:id="@+id/content_frame"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

and then swap out the Fragments when a Toolbar button is clicked, like this:

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    int id = item.getItemId();

    if(id == R.id.menu_item_1) {
        getSupportFragmentManager()
            .beginTransaction()
            .replace(R.id.content_frame, fragment1)
            .commit();
    } else if(id == R.id.menu_item_2) {
        getSupportFragmentManager()
            .beginTransaction()
            .replace(R.id.content_frame, fragment2)
            .commit();
    }

    return super.onOptionsItemSelected(item);
}

Obviously you will have to init your fragments beforehand and probably add a check to see if a certain fragment is already displayed before you do a transaction.