FloatingActionButton不会使用hide()方法隐藏

我试图隐藏 FloatingActionButton 当用户单击 fab 按钮固定在带有 hide() 方法,但晶圆厂不会隐藏。

当前使用支持库版本26.1.0

活动

public class A_TestActivity extends AppCompatActivity {

    FloatingActionButton fab;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.a_test_activity);
        fab = findViewById(R.id.fab);

        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                fab.hide();  // not working
                Toast.makeText(A_TestActivity.this, "hide()", Toast.LENGTH_SHORT).show();
            }
        });
    }
}

XML布局

<?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:id="@+id/coordinatorLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#AAAAAA">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical"/>

    <!-- Bottom Sheet -->
    <android.support.v4.widget.NestedScrollView
        android:id="@+id/vBottomSheetRoot"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@android:color/white"
        app:layout_behavior="android.support.design.widget.BottomSheetBehavior">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <TextView
                android:id="@+id/tv"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:text="Sample text" />
        </LinearLayout>

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

    <!-- Floating action button -->
    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:elevation="4dp"
        app:layout_anchor="@id/vBottomSheetRoot"
        app:layout_anchorGravity="top|right|end" />

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