<android.support.v7.widget.Toolbar xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fitsSystemWindows="true"
android:minHeight="?attr/actionBarSize">

    <ImageView
       android:id="@+id/backButton"
       android:background="@drawable/back_icon"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content" />

    <ImageView
       android:id="@+id/homeButton" 
       android:background="@drawable/menu_icon"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content" />
</android.support.v7.widget.Toolbar>

然后设置侦听器以执行诸如openDrawer之类的任务并转到上一屏幕.

Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
ImageView homeButton = (ImageView) toolbar.findViewById(R.id.homeButton);

homeButton.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
       drawerLayout.openDrawer(GravityCompat.START);
    }
});