工具栏选项菜单上的图像未显示

Question

工具栏

<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent">

<android.support.design.widget.AppBarLayout

    android:id="@+id/app_bar_layout"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <android.support.design.widget.CollapsingToolbarLayout
        android:padding="1dp"
        android:background="@color/white"
        android:id="@+id/collapsing_toolbar"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:contentScrim="?attr/colorPrimary"
        app:layout_scrollFlags="scroll|exitUntilCollapsed">

        <ImageView

            android:background="@color/white"
            android:src="@drawable/hackerpic"
            android:id="@+id/hackerpic"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:scaleType="centerCrop"
            app:layout_collapseMode="parallax"
            app:layout_collapseParallaxMultiplier="0.7" />

        <android.support.v7.widget.Toolbar
            app:titleTextColor="@color/white"
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            app:layout_collapseMode="pin">

            <RelativeLayout
                android:padding="2dp"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content">
                <TextView
                    android:text="Name"
                    android:layout_centerVertical="true"
                    android:layout_marginLeft="5dp"
                    android:id="@+id/name"
                    android:textColor="@color/white"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"
                    android:textSize="20dp"/>


            </RelativeLayout>


        </android.support.v7.widget.Toolbar>
    </android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>

代码

Toolbar toolbar = findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);

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



    return super.onOptionsItemSelected(item);
}


public boolean onNavigationItemSelected(MenuItem item) {
    int id = item.getItemId();
    Fragment fragment = null;
    if (id == R.id.share) {

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

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

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

    }
    return true;


}

我使用了折叠式工具栏布局，但以前从未使用过，所以我不确定哪里出了问题。单击工具栏右上角的我可以访问菜单，但是看不到菜单图像。