如何在滚动视图顶部添加浮动动作按钮

Question

我有一个浮动操作按钮，我想在滚动视图的顶部添加该按钮，即使您滚动该按钮也可以保留。我希望它在滚动视图的顶部和屏幕的右下角。我需要使用哪种视图组合来完成此任务？

这是xml文件：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:fab="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.nhscoding.safe2tell.STORIES"
    android:background="@color/stor_back">
    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="bottom"
        >

        <com.getbase.floatingactionbutton.FloatingActionButton
            android:id="@+id/pink_icon"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            fab:fab_icon="@drawable/ic_add"
            fab:fab_colorNormal="@color/fab_back"
            fab:fab_colorPressed="@color/fab_pressed_back"
            android:layout_gravity="end"
            android:layout_marginBottom="16dp"
            android:layout_marginRight="16dp"/>
        </LinearLayout>


    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent">

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



            <android.support.v7.widget.CardView
                xmlns:card_view="http://schemas.android.com/apk/res-auto"
                android:id="@+id/card_view1"
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:layout_marginTop="@dimen/card_margin_top"
                android:layout_marginBottom="@dimen/card_margin_bottom"
                android:layout_marginLeft="@dimen/card_margin_left"
                android:layout_marginRight="@dimen/card_margin_right"
                card_view:cardCornerRadius="@dimen/card_radius"
                >

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="@dimen/card_title_top"
                    android:layout_marginBottom="@dimen/card_title_bottom"
                    android:layout_marginLeft="@dimen/card_title_left"
                    android:layout_marginRight="@dimen/card_title_right"
                    android:text="@string/card1_title"
                    android:textSize="@dimen/card_title_size"
                    android:gravity="top"
                    android:id="@+id/title1"
                    />


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

            <android.support.v7.widget.CardView
                xmlns:card_view="http://schemas.android.com/apk/res-auto"
                android:id="@+id/card_view2"
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:layout_marginTop="@dimen/card_margin_top"
                android:layout_marginBottom="@dimen/card_margin_bottom"
                android:layout_marginLeft="@dimen/card_margin_left"
                android:layout_marginRight="@dimen/card_margin_right"
                card_view:cardCornerRadius="@dimen/card_radius"
                android:layout_below="@id/card_view1">

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="@dimen/card_title_top"
                    android:layout_marginBottom="@dimen/card_title_bottom"
                    android:layout_marginLeft="@dimen/card_title_left"
                    android:layout_marginRight="@dimen/card_title_right"
                    android:text="@string/card2_title"
                    android:textSize="@dimen/card_title_size"
                    android:gravity="top"
                    />

                <TextView
                    android:id="@+id/info_text2"
                    android:layout_marginTop="16dp"
                    android:layout_marginBottom="0dp"
                    android:layout_marginLeft="16dp"
                    android:layout_marginRight="16dp"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent"/>
            </android.support.v7.widget.CardView>

            <android.support.v7.widget.CardView
                xmlns:card_view="http://schemas.android.com/apk/res-auto"
                android:id="@+id/card_view3"
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:layout_marginTop="@dimen/card_margin_top"
                android:layout_marginBottom="@dimen/card_margin_bottom"
                android:layout_marginLeft="@dimen/card_margin_left"
                android:layout_marginRight="@dimen/card_margin_right"
                card_view:cardCornerRadius="@dimen/card_radius"
                android:layout_below="@id/card_view2">

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="@dimen/card_title_top"
                    android:layout_marginBottom="@dimen/card_title_bottom"
                    android:layout_marginLeft="@dimen/card_title_left"
                    android:layout_marginRight="@dimen/card_title_right"
                    android:text="@string/card3_title"
                    android:textSize="@dimen/card_title_size"
                    android:gravity="top"
                    />

                <TextView
                    android:id="@+id/info_text3"
                    android:layout_marginTop="16dp"
                    android:layout_marginBottom="0dp"
                    android:layout_marginLeft="16dp"
                    android:layout_marginRight="16dp"
                    android:layout_width="wrap_content"
                    android:layout_height="match_parent"/>
            </android.support.v7.widget.CardView>

            <android.support.v7.widget.CardView
                xmlns:card_view="http://schemas.android.com/apk/res-auto"
                android:id="@+id/card_view1"
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:layout_marginTop="@dimen/card_margin_top"
                android:layout_marginBottom="@dimen/card_margin_bottom"
                android:layout_marginLeft="@dimen/card_margin_left"
                android:layout_marginRight="@dimen/card_margin_right"
                card_view:cardCornerRadius="@dimen/card_radius">

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="@dimen/card_title_top"
                    android:layout_marginBottom="@dimen/card_title_bottom"
                    android:layout_marginLeft="@dimen/card_title_left"
                    android:layout_marginRight="@dimen/card_title_right"
                    android:text="@string/card4_title"
                    android:textSize="@dimen/card_title_size"
                    android:gravity="top"
                    android:id="@+id/title4"
                    />


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

            <android.support.v7.widget.CardView
                xmlns:card_view="http://schemas.android.com/apk/res-auto"
                android:id="@+id/card_view1"
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:layout_marginTop="@dimen/card_margin_top"
                android:layout_marginBottom="16dp"
                android:layout_marginLeft="@dimen/card_margin_left"
                android:layout_marginRight="@dimen/card_margin_right"
                card_view:cardCornerRadius="@dimen/card_radius">

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="@dimen/card_title_top"
                    android:layout_marginBottom="@dimen/card_title_bottom"
                    android:layout_marginLeft="@dimen/card_title_left"
                    android:layout_marginRight="@dimen/card_title_right"
                    android:text="@string/card5_title"
                    android:textSize="@dimen/card_title_size"
                    android:gravity="top"
                    android:id="@+id/title5"
                    />


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


            </LinearLayout>
        </ScrollView>




</RelativeLayout>

Answer 1

RelativeLayout中的较早的孩子倾向于漂浮在RelativeLayout中的较早的孩子之上。

（（我说“倾向于”是因为Android 5.0的elevation东西也起了作用，并且它们之间的关系是不确定的）

因此，要使浮动操作按钮（FAB）悬浮在ScrollView中的RelativeLayout上，请确保ScrollView首先在XML中定义，然后在FAB之后定义。这不会影响X / Y规则，但是应该使FAB出现在Z轴的ScrollView上。

[如果您仅支持Android 5.0+，另一种可能性是使用android:elevation本身来提高FAB。

Answer 2

尝试一下：

android：layout_alignParentRight =“ true”

android：layout_alignParentBottom =“ true”

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:fab="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.nhscoding.safe2tell.STORIES"
    android:background="@color/stor_back">


    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent">

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


            <android.support.v7.widget.CardView xmlns:card_view="http://schemas.android.com/apk/res-auto"
                android:id="@+id/card_view1"
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:layout_marginTop="@dimen/card_margin_top"
                android:layout_marginBottom="@dimen/card_margin_bottom"
                android:layout_marginLeft="@dimen/card_margin_left"
                android:layout_marginRight="@dimen/card_margin_right"
                card_view:cardCornerRadius="@dimen/card_radius">

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="@dimen/card_title_top"
                    android:layout_marginBottom="@dimen/card_title_bottom"
                    android:layout_marginLeft="@dimen/card_title_left"
                    android:layout_marginRight="@dimen/card_title_right"
                    android:text="@string/card1_title"
                    android:textSize="@dimen/card_title_size"
                    android:gravity="top"
                    android:id="@+id/title1" />


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

            <android.support.v7.widget.CardView xmlns:card_view="http://schemas.android.com/apk/res-auto"
                android:id="@+id/card_view2"
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:layout_marginTop="@dimen/card_margin_top"
                android:layout_marginBottom="@dimen/card_margin_bottom"
                android:layout_marginLeft="@dimen/card_margin_left"
                android:layout_marginRight="@dimen/card_margin_right"
                card_view:cardCornerRadius="@dimen/card_radius"
                android:layout_below="@id/card_view1">

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="@dimen/card_title_top"
                    android:layout_marginBottom="@dimen/card_title_bottom"
                    android:layout_marginLeft="@dimen/card_title_left"
                    android:layout_marginRight="@dimen/card_title_right"
                    android:text="@string/card2_title"
                    android:textSize="@dimen/card_title_size"
                    android:gravity="top" />

                <TextView
                    android:id="@+id/info_text2"
                    android:layout_marginTop="16dp"
                    android:layout_marginBottom="0dp"
                    android:layout_marginLeft="16dp"
                    android:layout_marginRight="16dp"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent" />
            </android.support.v7.widget.CardView>

            <android.support.v7.widget.CardView xmlns:card_view="http://schemas.android.com/apk/res-auto"
                android:id="@+id/card_view3"
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:layout_marginTop="@dimen/card_margin_top"
                android:layout_marginBottom="@dimen/card_margin_bottom"
                android:layout_marginLeft="@dimen/card_margin_left"
                android:layout_marginRight="@dimen/card_margin_right"
                card_view:cardCornerRadius="@dimen/card_radius"
                android:layout_below="@id/card_view2">

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="@dimen/card_title_top"
                    android:layout_marginBottom="@dimen/card_title_bottom"
                    android:layout_marginLeft="@dimen/card_title_left"
                    android:layout_marginRight="@dimen/card_title_right"
                    android:text="@string/card3_title"
                    android:textSize="@dimen/card_title_size"
                    android:gravity="top" />

                <TextView
                    android:id="@+id/info_text3"
                    android:layout_marginTop="16dp"
                    android:layout_marginBottom="0dp"
                    android:layout_marginLeft="16dp"
                    android:layout_marginRight="16dp"
                    android:layout_width="wrap_content"
                    android:layout_height="match_parent" />
            </android.support.v7.widget.CardView>

            <android.support.v7.widget.CardView xmlns:card_view="http://schemas.android.com/apk/res-auto"
                android:id="@+id/card_view1"
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:layout_marginTop="@dimen/card_margin_top"
                android:layout_marginBottom="@dimen/card_margin_bottom"
                android:layout_marginLeft="@dimen/card_margin_left"
                android:layout_marginRight="@dimen/card_margin_right"
                card_view:cardCornerRadius="@dimen/card_radius">

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="@dimen/card_title_top"
                    android:layout_marginBottom="@dimen/card_title_bottom"
                    android:layout_marginLeft="@dimen/card_title_left"
                    android:layout_marginRight="@dimen/card_title_right"
                    android:text="@string/card4_title"
                    android:textSize="@dimen/card_title_size"
                    android:gravity="top"
                    android:id="@+id/title4" />


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

            <android.support.v7.widget.CardView xmlns:card_view="http://schemas.android.com/apk/res-auto"
                android:id="@+id/card_view1"
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:layout_marginTop="@dimen/card_margin_top"
                android:layout_marginBottom="16dp"
                android:layout_marginLeft="@dimen/card_margin_left"
                android:layout_marginRight="@dimen/card_margin_right"
                card_view:cardCornerRadius="@dimen/card_radius">

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="@dimen/card_title_top"
                    android:layout_marginBottom="@dimen/card_title_bottom"
                    android:layout_marginLeft="@dimen/card_title_left"
                    android:layout_marginRight="@dimen/card_title_right"
                    android:text="@string/card5_title"
                    android:textSize="@dimen/card_title_size"
                    android:gravity="top"
                    android:id="@+id/title5" />


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


        </LinearLayout>
    </ScrollView>

        <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="bottom"
        android:layout_alignParentRight="true"
        android:layout_alignParentBottom="true"
        android:layout_margin="10dp">

        <com.getbase.floatingactionbutton.FloatingActionButton
            android:id="@+id/pink_icon"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            fab:fab_icon="@drawable/ic_add"
            fab:fab_colorNormal="@color/fab_back"
            fab:fab_colorPressed="@color/fab_pressed_back"
            android:layout_gravity="end"
            android:layout_marginBottom="16dp"
            android:layout_marginRight="16dp" />
    </LinearLayout>

</RelativeLayout>

Answer 3

相对布局为基础。在该滚动视图中，then浮动操作按钮（将alignParent Right和Bottom设置为true）。

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
                android:layout_width="match_parent"
                android:layout_height="match_parent">

    <ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
                xmlns:tools="http://schemas.android.com/tools"
                android:layout_height="match_parent"
                android:layout_width="match_parent">

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

            <TextView
                    android:text="Your content"
                    android:layout_width="wrap_content"
                    android:layout_height="wrap_content"/>

        </LinearLayout>

    </ScrollView>

    <android.support.design.widget.FloatingActionButton
            android:id="@+id/fab1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"

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

            android:src="@drawable/ic_add"
            android:layout_margin="16dp"/>

</RelativeLayout>

BR马赛厄斯

Answer 4

您可以使用android.support.design.widget.CoordinatorLayout作为父布局。使两个xml之一，您可以在其中设置滚动条或列表。另一个是父容器，其中包含您的FloatingActionButton的全部信息。

activity_main.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:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:context=".MainActivity">

    <android.support.design.widget.AppBarLayout
        android:layout_height="wrap_content"
        android:layout_width="match_parent"
        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:popupTheme="@style/AppTheme.PopupOverlay" />

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

    <include layout="@layout/content_main" />

    <android.support.design.widget.FloatingActionButton
        android:id="@+id/fab"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom|end"
        app:elevation="6dp"
        app:backgroundTint="@color/colorAccent"
        app:pressedTranslationZ="12dp"
        android:layout_margin="@dimen/fab_margin"
        android:src="@drawable/ic_add" />

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

content_main.xml

您可以在此处放置ScrollBar。非常简单。

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:gravity="center"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:showIn="@layout/activity_main"
    tools:context=".MainActivity">

    <ScrollView
        android:layout_width="match_parent"
        android:layout_height="match_parent">

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


            <android.support.v7.widget.CardView xmlns:card_view="http://schemas.android.com/apk/res-auto"
                android:id="@+id/card_view1"
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:layout_marginTop="@dimen/card_margin_top"
                android:layout_marginBottom="@dimen/card_margin_bottom"
                android:layout_marginLeft="@dimen/card_margin_left"
                android:layout_marginRight="@dimen/card_margin_right"
                card_view:cardCornerRadius="@dimen/card_radius">

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="@dimen/card_title_top"
                    android:layout_marginBottom="@dimen/card_title_bottom"
                    android:layout_marginLeft="@dimen/card_title_left"
                    android:layout_marginRight="@dimen/card_title_right"
                    android:text="@string/card1_title"
                    android:textSize="@dimen/card_title_size"
                    android:gravity="top"
                    android:id="@+id/title1" />


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

            <android.support.v7.widget.CardView xmlns:card_view="http://schemas.android.com/apk/res-auto"
                android:id="@+id/card_view2"
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:layout_marginTop="@dimen/card_margin_top"
                android:layout_marginBottom="@dimen/card_margin_bottom"
                android:layout_marginLeft="@dimen/card_margin_left"
                android:layout_marginRight="@dimen/card_margin_right"
                card_view:cardCornerRadius="@dimen/card_radius"
                android:layout_below="@id/card_view1">

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="@dimen/card_title_top"
                    android:layout_marginBottom="@dimen/card_title_bottom"
                    android:layout_marginLeft="@dimen/card_title_left"
                    android:layout_marginRight="@dimen/card_title_right"
                    android:text="@string/card2_title"
                    android:textSize="@dimen/card_title_size"
                    android:gravity="top" />

                <TextView
                    android:id="@+id/info_text2"
                    android:layout_marginTop="16dp"
                    android:layout_marginBottom="0dp"
                    android:layout_marginLeft="16dp"
                    android:layout_marginRight="16dp"
                    android:layout_width="match_parent"
                    android:layout_height="match_parent" />
            </android.support.v7.widget.CardView>

            <android.support.v7.widget.CardView xmlns:card_view="http://schemas.android.com/apk/res-auto"
                android:id="@+id/card_view3"
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:layout_marginTop="@dimen/card_margin_top"
                android:layout_marginBottom="@dimen/card_margin_bottom"
                android:layout_marginLeft="@dimen/card_margin_left"
                android:layout_marginRight="@dimen/card_margin_right"
                card_view:cardCornerRadius="@dimen/card_radius"
                android:layout_below="@id/card_view2">

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="@dimen/card_title_top"
                    android:layout_marginBottom="@dimen/card_title_bottom"
                    android:layout_marginLeft="@dimen/card_title_left"
                    android:layout_marginRight="@dimen/card_title_right"
                    android:text="@string/card3_title"
                    android:textSize="@dimen/card_title_size"
                    android:gravity="top" />

                <TextView
                    android:id="@+id/info_text3"
                    android:layout_marginTop="16dp"
                    android:layout_marginBottom="0dp"
                    android:layout_marginLeft="16dp"
                    android:layout_marginRight="16dp"
                    android:layout_width="wrap_content"
                    android:layout_height="match_parent" />
            </android.support.v7.widget.CardView>

            <android.support.v7.widget.CardView xmlns:card_view="http://schemas.android.com/apk/res-auto"
                android:id="@+id/card_view1"
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:layout_marginTop="@dimen/card_margin_top"
                android:layout_marginBottom="@dimen/card_margin_bottom"
                android:layout_marginLeft="@dimen/card_margin_left"
                android:layout_marginRight="@dimen/card_margin_right"
                card_view:cardCornerRadius="@dimen/card_radius">

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="@dimen/card_title_top"
                    android:layout_marginBottom="@dimen/card_title_bottom"
                    android:layout_marginLeft="@dimen/card_title_left"
                    android:layout_marginRight="@dimen/card_title_right"
                    android:text="@string/card4_title"
                    android:textSize="@dimen/card_title_size"
                    android:gravity="top"
                    android:id="@+id/title4" />


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

            <android.support.v7.widget.CardView xmlns:card_view="http://schemas.android.com/apk/res-auto"
                android:id="@+id/card_view1"
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:layout_marginTop="@dimen/card_margin_top"
                android:layout_marginBottom="16dp"
                android:layout_marginLeft="@dimen/card_margin_left"
                android:layout_marginRight="@dimen/card_margin_right"
                card_view:cardCornerRadius="@dimen/card_radius">

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:layout_marginTop="@dimen/card_title_top"
                    android:layout_marginBottom="@dimen/card_title_bottom"
                    android:layout_marginLeft="@dimen/card_title_left"
                    android:layout_marginRight="@dimen/card_title_right"
                    android:text="@string/card5_title"
                    android:textSize="@dimen/card_title_size"
                    android:gravity="top"
                    android:id="@+id/title5" />


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


        </LinearLayout>
    </ScrollView>
</RelativeLayout>