使用BottomNavigationView的FloatingActionButton

Question

我无法定位我的FAB.它应该在右下角,但在BottonNavigationView之上.

1)我可以在coordinateLayout内部没有RelativeLayout的情况下实现这一点吗？

2)告诉我如何

3)我应该使用FrameLayout作为片段的容器吗？

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

<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/AppTheme.AppBarOverlay">

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

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

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

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

</FrameLayout>

<android.support.design.widget.FloatingActionButton
    android:id="@+id/fab_electricity"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="end|bottom"
    android:layout_margin="@dimen/fab_margin"
    app:layout_anchorGravity="bottom|right|end"
    app:srcCompat="@drawable/ic_add_electro" />

<android.support.design.widget.BottomNavigationView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_gravity="bottom">

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

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

Answer 1

快速搜索FloatingActionButton.Behavior告诉我们以下内容.

@Override
public void onAttachedToLayoutParams(@NonNull CoordinatorLayout.LayoutParams lp) {
    if (lp.dodgeInsetEdges == Gravity.NO_GRAVITY) {
        // If the developer hasn't set dodgeInsetEdges, lets set it to BOTTOM so that
        // we dodge any Snackbars
        lp.dodgeInsetEdges = Gravity.BOTTOM;
    }
}

由于BottomNavigationView也位于布局的底部.添加以下元素,BottomNavigationView并CoordinatorLayout自动处理插入和躲避.

app:layout_insetEdge="bottom"