android - 单击箭头图标时如何在抽屉导航的 Android 中使用 onBackPressed？

Question

我正在使用抽屉导航，当我点击工具栏的箭头时，onBackPressed 方法不会运行，但是当我点击底部面板的背面时，movil 正在运行。我不明白如何使用箭头按钮来做同样的事情。

公共(public)类 MainActivity 扩展 AppCompatActivity 实现 NavigationView.OnNavigationItemSelectedListener， BlankFragment.OnFragmentInteractionListener {

ActionBarDrawerToggle toggle;
DrawerLayout drawer;

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

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    drawer.setFocusableInTouchMode(true);

    toggle = new ActionBarDrawerToggle(
            this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);

    drawer.setDrawerListener(toggle);

    toggle.syncState();

    NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
    navigationView.setNavigationItemSelectedListener(this);

    getSupportFragmentManager().beginTransaction()
            .replace(R.id.vista, new BlankFragment())
            .addToBackStack(null)
            .commit();

}


@Override
public void onBackPressed() {
    super.onBackPressed();
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.

    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }
    if (id == android.R.id.home) {
        onBackPressed();
    }
    return super.onOptionsItemSelected(item);
}

@SuppressWarnings("StatementWithEmptyBody")
@Override
public boolean onNavigationItemSelected(MenuItem item) {
    // Handle navigation view item clicks here.
    int id = item.getItemId();

    if (id == R.id.nav_camera) {

    } else if (id == R.id.nav_gallery) {

    } else if (id == R.id.nav_slideshow) {

    } else if (id == R.id.nav_manage) {

    } else if (id == R.id.nav_share) {

    } else if (id == R.id.nav_send) {

    }

    drawer.closeDrawer(GravityCompat.START);
    return true;
}

@Override
public void onFragmentInteraction() {

    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    getSupportFragmentManager().beginTransaction()
            .replace(R.id.vista, new BlankFragment2())
            .addToBackStack(null)
            .commit();

}

Answer 1

首先启用操作栏的后退箭头..

ActionBar actionBar = getSupportActionBar();
if(actionBar!=null){
    actionBar.setDisplayHomeAsUpEnabled(true);
}

第二次使用 android.R.id.home 访问 onOptionsItemSelected() 上的按钮

@Override
public boolean onOptionsItemSelected(MenuItem item) {
   switch (item.getItemId()){           
       case android.R.id.home:
           onBackPressed();
         break;
    }
    return super.onOptionsItemSelected(item);
}