Android工具栏图标缺失,但仍可选择

由于某种原因,我不明白为什么我的汉堡包图标看不到,但仍然可以被选中,并且所有的东西都被隔开,好像它仍然在那里。这也发生在3个水平点图标的另一侧,我已经设置到注销部分。

主要活动。Java语言

public class MainActivity extends AppCompatActivity implements 
NavigationView.OnNavigationItemSelectedListener {

private Toolbar mToolbar;
private DrawerLayout mDrawerLayout;




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

    // Find our drawer view
    mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);

    setupToolbarMenu();
    setupNavigationDrawerMenu();

}
private void setupToolbarMenu() {

    mToolbar = (Toolbar) findViewById(R.id.toolbar);
    mToolbar.setTitle("Recovery Toolkit");
}
private void setupNavigationDrawerMenu() {

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

    ActionBarDrawerToggle drawerToggle = new 
    ActionBarDrawerToggle(this,
            mDrawerLayout,
            mToolbar,
            R.string.drawer_open,
            R.string.drawer_close);

    mDrawerLayout.addDrawerListener(drawerToggle);
    drawerToggle.syncState();
}

活动_main。xml

<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context=".activity.SplashActivity"
tools:openDrawer="start">

<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content">

<android.support.design.widget.CoordinatorLayout
    android:id="@+id/main_content"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

<android.support.design.widget.AppBarLayout
    android:id="@+id/appbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/MyMaterialTheme">

<include layout="@layout/toolbar" />

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

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

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

</LinearLayout>


<!-- Navigation View -->
<android.support.design.widget.NavigationView
    android:id="@+id/nav_view"
    android:layout_width="@dimen/nav_drawer_width"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    app:headerLayout="@layout/nav_header_main"
    android:fitsSystemWindows="true"
    app:menu="@menu/activity_main_drawer"
    android:theme="@style/MyMaterialTheme"/>

工具栏。xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout 
xmlns:android="http://schemas.android.com/apk/res/android"
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"
android:fitsSystemWindows="true"tools:context="com.granitemountainbhc.recoverytoolkit.activity.MainActivity">

<android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:theme="@style/MyMaterialTheme">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="?attr/colorPrimary"
        app:popupTheme="@style/MyMaterialTheme"
        app:layout_scrollFlags="scroll|enterAlways" />



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

<FrameLayout
    android:id="@+id/frame"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    app:layout_behavior="@string/appbar_scrolling_view_behavior">
</FrameLayout>

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

nav\u header\u main。xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="@dimen/nav_drawer_width"
android:layout_height="190dp"
android:elevation="16dp"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:background="@drawable/background_header">



<LinearLayout
    android:layout_width="@dimen/nav_drawer_width"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:paddingBottom="15dp"
    android:paddingStart="15dp"
    android:paddingEnd="15dp"
    android:layout_alignParentTop="true"
    android:layout_alignParentStart="true"
    android:layout_marginTop="56dp">


    <ImageView
        android:id="@+id/user_profile"
        android:layout_width="@dimen/nav_drawer_profile_image_size"
        android:layout_height="50dp"
        android:gravity="bottom"
        app:srcCompat="@drawable/ic_account_circle_white_64dp"
        tools:ignore="ContentDescription" />

    <ImageView
        android:layout_width="@dimen/nav_drawer_width"
        android:layout_height="wrap_content"
        android:contentDescription="@string/item_desc" />


    <TextView
        android:id="@+id/txvName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_weight="3"
        android:fontFamily="roboto-bold"
        android:gravity="bottom"
        android:text="@string/user_name"
        android:textColor="@color/colorPrimaryText"
        android:textSize="14sp" />

    <TextView
        android:id="@+id/txvEmail"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_weight="1"
        android:fontFamily="roboto"
        android:gravity="bottom"
        android:text="@string/email"
        android:textColor="@color/colorPrimaryText"
        android:textSize="14sp" />

</LinearLayout>