浮动操作按钮（FAB）位于xml片段中的ListView上方？

Question

I used code from here . In my case it looks like

<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".fragments.FragmentList"
    android:orientation="vertical"
    android:id="@+id/linear">

    <ListView
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:fab="http://schemas.android.com/apk/res-auto"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/listView" />

</LinearLayout>

<android.support.design.widget.CoordinatorLayout

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

<android.support.design.widget.FloatingActionButton
    android:id="@+id/fab"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/ic_add_white_24dp"
    android:layout_gravity="bottom|end"
    fab:elevation="6dp"
    fab:pressedTranslationZ="12dp"
    fab:backgroundTint="@color/accent"
    app:layout_anchor="@id/listView"/>
</android.support.design.widget.CoordinatorLayout>

But i have "multiple root tags" in Android Studio. What i did wrong? Please help me, i cant understand ((

Answer 1

Use this layout instead:

<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".fragments.FragmentList"
android:orientation="vertical"
android:id="@+id/linear">

<ListView
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:fab="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:id="@+id/listView" />


<android.support.design.widget.FloatingActionButton
    android:id="@+id/fab"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@drawable/ic_add_white_24dp"
    android:layout_gravity="bottom|end"
    fab:elevation="6dp"
    fab:pressedTranslationZ="12dp"
    fab:backgroundTint="@color/accent"
    app:layout_anchor="@id/listView"/>

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

Answer 2

改变这行代码android：layout_gravity =“bottom | end”到android：layout_gravity =“top”

Answer 3

android:layout_alignParentBottom="true"
android:layout_alignParentRight="true"
android:layout_alignParentEnd="true"

This will set the FAB to bottom right.