How to add a spinner next to a menu in the toolbar

问题

I want my spinner to be next to my menu in the toolbar (to the left of the menu), but currently the spinner appear below the menu. Do i have to add it somehow inside the onCreateOptionsMenu(Menu menu)

My Activity:

  protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_list);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        getSupportActionBar().setDisplayShowTitleEnabled(false);

 Spinner spinner = (Spinner) findViewById(R.id.travelType_spinner);
        // Create an ArrayAdapter using the string array and a default spinner layout
        ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
                R.array.travelType_array, R.layout.spinner_item);
        // Specify the layout to use when the list of choices appears
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
        // Apply the adapter to the spinner
        if (spinner != null) {
            spinner.setAdapter(adapter);
        }

Layout:

<android.support.design.widget.AppBarLayout
        android:id="@+id/appBarLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay">

        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="?attr/colorPrimary"
            app:popupTheme="@style/AppTheme.PopupOverlay" />

        <Spinner
            android:id="@+id/travelType_spinner"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            />
    </android.support.design.widget.AppBarLayout>

Spinner_item.xml

<TextView
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textColor="@color/whiteText"
    android:textStyle="bold"
    android:padding="15dp"/>

回答1:

Add menu Item

<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <item
        android:id="@+id/spinner"
        android:title="ActionBar Spinner"
        app:actionViewClass="android.widget.Spinner"
        android:background="#ff00"
        app:showAsAction="always" />
</menu>

Java

@Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.android_action_bar_spinner_menu, menu);

        MenuItem item = menu.findItem(R.id.spinner);
        Spinner spinner = (Spinner) item.getActionView();

        ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
                R.array.spinner_list_item_array, android.R.layout.simple_spinner_item);
        adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

        spinner.setAdapter(adapter);
        return true;
    }

or

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="?attr/colorPrimaryDark"
    android:minHeight="?attr/actionBarSize"
    app:popupTheme="@style/ThemeOverlay.AppCompat.Light"
     >

    <Spinner
        android:id="@+id/spinner_nav"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</android.support.v7.widget.Toolbar>

回答2:

Adding to the above answer, your activity needs to implement onItemSelectedListener, and in the onItemSelected method you do your work.

You will also need to tell the spinner who is listening, in onCreateOptionsMenu, add this line:

spinner.setOnItemSelectedListener(this);

which will cause your spinner to call the onItemSelected method of the activity.

来源：https://stackoverflow.com/questions/37250397/how-to-add-a-spinner-next-to-a-menu-in-the-toolbar