ToolBar 添加menu，设置返回按钮，设置item的监听事件

链接参考：

Add an up action
添加Action按钮
更丰富在向上操作

效果图：

AndroidManifest.xml

 <application
 		...
        android:theme="@style/AppTheme.NoActionBar">
        
        <activity android:name=".MainActivity">
		...
        </activity>
        
        <activity
            android:name=".MyChildActivity"
            android:label="title_activity_my_child"
            android:theme="@style/AppTheme.NoActionBar"
            android:parentActivityName=".MainActivity"
            >
        </activity>
    </application>

MainActivity.java

public class MainActivity extends AppCompatActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void startAAty(View view) {
        startActivity(new Intent(this,MyChildActivity.class));
    }
}

MyChildActivity.java （实现绑定menu，和响应menu 操作）

public class MyChildActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.content_my_child);
        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        // Get a support ActionBar corresponding to this toolbar
        ActionBar ab = getSupportActionBar();

        // Enable the Up button
        ab.setDisplayHomeAsUpEnabled(true);

    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // 为ActionBar扩展菜单项
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.appbar_item, menu);
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()){
            case R.id.action_favorite:
                Toast.makeText(this, "最爱", Toast.LENGTH_SHORT).show();
                return true;
            case R.id.action_settings:
                Toast.makeText(this, "设置", Toast.LENGTH_SHORT).show();
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }
}

activity_main.xml （启动子活动布局）

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:onClick="startAAty"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="启动另一个Aty"
        />

</LinearLayout>

content_my_child.xml （子活动布局）

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:context=".MyChildActivity"
    >

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        android:elevation="4dp"
        android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
        app:popupTheme="@style/ThemeOverlay.AppCompat.Light"

        />
    
</LinearLayout>

appbar_item.xml （menu 资源文件）

<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <!-- "Mark Favorite", should appear as action button if possible -->
    <item
        android:id="@+id/action_favorite"
        android:icon="@mipmap/ic_launcher_round"
        android:title="最爱"
        app:showAsAction="ifRoom"/>

    <!-- Settings, should always be in the overflow -->
    <item android:id="@+id/action_settings"
        android:title="设置"
        app:showAsAction="never"/>
</menu>