使用ToolBar和AppCompatActivity实现后退导航

Question

我在尝试更改导航抽屉图标后退箭头并将其用作后退按钮。但是当我getSupportActionBar().setDisplayHomeAsUpEnabled(true);什么都没有发生。

MainActivity.java

public class MainActivity extends AppCompatActivity 
implements NavigationView.OnNavigationItemSelectedListener { 
    ActionBarDrawerToggle toggle; 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); 
     setSupportActionBar(toolbar); 

     FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab); 
     fab.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View view) { 
       Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG) 
       .setAction("Action", null).show(); 
      } 
     }); 

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

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

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

     getSupportActionBar().setDisplayHomeAsUpEnabled(true); 
     getSupportActionBar().setHomeButtonEnabled(true); 
     getSupportActionBar().setDisplayShowHomeEnabled(true); 
    } 

    @Override 
    public void onPostCreate(Bundle savedInstanceState) { 
     super.onPostCreate(savedInstanceState); 
     getSupportActionBar().setDisplayHomeAsUpEnabled(true); 
//getSupportActionBar().setDisplayShowHomeEnabled(true); 
     toggle.syncState(); 
    } 

    @Override 
    public void onBackPressed() { 
     DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); 
     if (drawer.isDrawerOpen(GravityCompat.START)) { 
      drawer.closeDrawer(GravityCompat.START); 
     } else { 
      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) { 
     if(toggle.onOptionsItemSelected(item)) { 
      return true; 
     } 

// 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; 
     } 

     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) { 
// Handle the camera action 
     } 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) { 

     } 

     DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout); 
     drawer.closeDrawer(GravityCompat.START); 
     return true; 
    } 
} 

当我改变ActionBarDrawerToggle的构造函数

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

，图标也变为后退箭头，但它的功能就像一个抽屉切换，而不是像后退按钮（因为onOptionsItemSelected未被调用）。

使其工作的正确方法是什么？

Answer 1

试试这个，

toggle.setDrawerIndicatorEnabled(false); 

编码快乐..