将小吃栏移动到底部栏上方

我在新的底栏上遇到了一些问题。
我无法强制将小吃栏移动到底部栏上方（这就是设计指南告诉我应该的方式https://www.google.com/design/spec/components/bottom-navigation.html#bottom-navigation-specs https://www.google.com/design/spec/components/bottom-navigation.html#bottom-navigation-specs).

这是我的activity_main.xml

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

<include
    layout="@layout/app_bar_main_activity"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

<android.support.design.widget.NavigationView
    android:id="@+id/nav_view"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:layout_gravity="start"
    android:fitsSystemWindows="true"
    app:headerLayout="@layout/nav_header_main_activity"
    app:menu="@menu/activity_main_drawer" />

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

这是我的 app_bar_main_activity.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:id="@+id/main_content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="test.tab_activity">

<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:theme="@style/MyAppTheme.NoActionBar.AppBarOverlay">

    <android.support.v7.widget.Toolbar
        android:id="@+id/main_activity_toolbar"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:background="?attr/colorPrimary"
        app:layout_scrollFlags="scroll|enterAlways"
        app:popupTheme="@style/MyAppTheme.NoActionBar.PopupOverlay">

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

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



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

<LinearLayout 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:orientation="vertical">

    <android.support.v4.view.ViewPager
        android:id="@+id/view_pager"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1" />

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="end|bottom"
        android:layout_margin="@dimen/fab_margin"
        android:src="@drawable/ic_add_white_24dp" />

    <android.support.design.widget.TabLayout
        android:id="@+id/tab_layout"
        style="@style/AppTabLayout"
        android:layout_width="match_parent"
        android:layout_height="56dp"
        android:background="?attr/colorPrimary"
        />

</LinearLayout>

main_activity.java 中的小吃栏看起来像这样

FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Snackbar.make(findViewById(R.id.main_content), "Replace with your own action", Snackbar.LENGTH_LONG)
                    .setAction("Action", null).show();
        }
    });

通过材料组件库，您可以使用setAnchorView https://github.com/material-components/material-components-android/blob/master/docs/components/Snackbar.md#anchoring-a-snackbar方法来制作一个Snackbar显示在特定视图上方。

在你的情况下，如果你使用的是BottomAppBar和一个晶圆厂，你应该定义fab in the setAanchorView。 就像是：

FloatingActionButton fab = findViewById(R.id.fab);
Snackbar snackbar = Snackbar.make(view, "Snackbar over BottomAppBar", Snackbar.LENGTH_LONG);
snackbar.setAnchorView(fab);

结果：

With a BottomNavigationView您可以将其定义为anchorView：

    Snackbar snackbar = Snackbar.make(view,"Snackbar over BottomNav",Snackbar.LENGTH_INDEFINITE);
    snackbar.setAnchorView(bottomNavigationView);
    snackbar.show();

Result: