DrawerToggle可能不会显示，因为NavigationIcon不可见。您可能需要调用actionbar.setDisplayHomeAsUpEnabled（true）;

Question

即使我已经调用setDisplayHomeAsUpEnabled（true），插入符号图标也不显示

 private ViewPager mViewPager;

private DrawerLayout mDrawerLayout;
private ActionBarDrawerToggle mToggle;

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

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    // Create the adapter that will return a fragment for each of the three
    // primary sections of the activity.
    mSectionsPagerAdapter = new SectionsPagerAdapter(getSupportFragmentManager());


    // Set up the ViewPager with the sections adapter.
    mViewPager = (ViewPager) findViewById(R.id.container);
    mViewPager.setAdapter(mSectionsPagerAdapter);

    mDrawerLayout = (DrawerLayout) findViewById(R.id.drawerLayout);
    mToggle = new ActionBarDrawerToggle(this, mDrawerLayout, R.string.open, R.string.close);

    mDrawerLayout.addDrawerListener(mToggle);
    mToggle.syncState();

    getSupportActionBar().setDefaultDisplayHomeAsUpEnabled(true);

    TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
    tabLayout.setupWithViewPager(mViewPager);

}

我正在创建一个包含选项卡式和导航活动的页面

这是我的XML文件

<?xml version="1.0" encoding="utf-8"?>

<android.support.v4.widget.DrawerLayout
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/drawerLayout">

    <!--navigation bar-->

    <android.support.design.widget.NavigationView xmlns:android="http://schemas.android.com/apk/res/android"
    tools:context="naufal.com.tugasakhir.HomePageTab"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    android:background="@drawable/nav_back"
    android:focusableInTouchMode="false"></android.support.design.widget.NavigationView>

    <!--tool & tab bar-->

    <android.support.design.widget.AppBarLayout
    android:id="@+id/appbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:paddingTop="@dimen/appbar_padding_top"
    >

    <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"
    app:layout_scrollFlags="scroll|enterAlways">

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

    <android.support.design.widget.TabLayout
    android:id="@+id/tabs"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
        android:background="#2A363B"
        app:tabSelectedTextColor="@color/primary"
        app:tabIndicatorColor="@color/primary"
        />

        <android.support.v4.view.ViewPager
            android:id="@+id/container"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@color/accent"
            app:layout_behavior="@string/appbar_scrolling_view_behavior"
            />

    </android.support.design.widget.AppBarLayout>

</android.support.v4.widget.DrawerLayout>

感谢您的帮助。