MapsActivity标题栏中的Android-Back按钮

Question

<application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/Theme.AppCompat.Light.NoActionBar" >
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <meta-data
            android:name="com.google.android.geo.API_KEY"
            android:value="@string/google_maps_key"
            />

        <activity
            android:name=".MapsActivity"
            android:label="@string/title_activity_maps"
            android:parentActivityName=".MainActivity" >
            <!-- Parent activity meta-data to support 4.0 and lower -->
            <meta-data
                android:name="android.support.PARENT_ACTIVITY"
                android:value="com.shmj.monmemorableplaces.MainActivity" />
        </activity>
    </application>

public class MapsActivity extends AppCompatActivity implements OnMapReadyCallback {

    private GoogleMap mMap;

    SupportMapFragment mapFragment;
    Intent mainIntent;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);
        mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);

        mainIntent = new Intent(getApplicationContext(), MainActivity.class);

        ActionBar actionBar = getActionBar();
        getActionBar().setHomeButtonEnabled(true);
        getActionBar().setDisplayHomeAsUpEnabled(true);   

    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case android.R.id.home:
                mainIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
                startActivity(mainIntent);
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }
}

Answer 1

public class MapsActivity extends AppCompatActivity

如果您正在使用最新的appcompact库，请使用AppCompactity。

也会改变

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_maps);

    ActionBar actionBar = getSupportActionBar();
    assert actionBar != null;
    actionBar.setDisplayHomeAsUpEnabled(true);
    actionBar.setHomeButtonEnabled(true);

    mapFragment = (SupportMapFragment) getSupportFragmentManager()
            .findFragmentById(R.id.map);
    mapFragment.getMapAsync(this);

    mainIntent = new Intent(getApplicationContext(), MainActivity.class);

}

请查看此了解更多详细信息。