在卡片视图上锚定一个浮动按钮

Question

我尝试在卡片视图上锚定一个浮动按钮，但没有成功。

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


    <android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:card_view="http://schemas.android.com/apk/res-auto"
        android:id="@+id/card_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="4dp"
        android:layout_marginLeft="4dp"
        android:layout_marginRight="4dp"
        android:layout_marginTop="8dp"
        android:background="@android:color/white"
        card_view:cardCornerRadius="2dp"
        card_view:cardElevation="2dp">


            ..... my view ...


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

    <android.support.design.widget.FloatingActionButton
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_height="wrap_content"
        android:layout_width="wrap_content"
        app:layout_anchor="@id/card_view"
        app:layout_anchorGravity="bottom|end|right"
        android:layout_margin="16dp"
        android:clickable="true"/>

</LinearLayout>

结果是这样的：

我希望浮动按钮看起来像绿色圆圈。 RecyclerView中使用了这个布局

这是实现这一目标的方法吗？

Answer 1

你能在下面的代码中添加你的浮动按钮

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"

>

<RelativeLayout
    android:layout_width="match_parent"
    android:layout_height="200dp"
    android:orientation="vertical"
    android:layout_alignParentBottom="true"
    android:layout_alignParentLeft="true"
    android:layout_alignParentStart="true"
    android:layout_marginBottom="297dp"
    android:id="@+id/relativeLayout">


    <android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:card_view="http://schemas.android.com/apk/res-auto"
        android:id="@+id/card_view"
        android:layout_width="match_parent"
        android:layout_height="fill_parent"
        android:layout_marginBottom="4dp"
        android:layout_marginLeft="4dp"
        android:layout_marginRight="4dp"
        android:layout_marginTop="8dp"

        android:background="@android:color/white"
        card_view:cardCornerRadius="2dp"
        card_view:cardElevation="2dp">


        ..... my view ...


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

</RelativeLayout>

<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:srcCompat="@android:drawable/ic_dialog_email"
    android:layout_marginRight="12dp"
    android:layout_marginEnd="12dp"
    android:layout_marginTop="165dp"
    android:layout_alignTop="@+id/relativeLayout"
    android:layout_alignParentRight="true"
    android:layout_alignParentEnd="true" />

Answer 2

在发布一个问题之前，先用谷歌搜索一下，第二个结果是answer

编辑

我在一个单独的项目中实现了它，它工作正常......

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

<android.support.v4.widget.NestedScrollView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    >

    <android.support.v7.widget.CardView
        android:id="@+id/cv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="16dp">

        <TextView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="The Android Support Library package is a set of code libraries that provide backward-compatible versions of Android framework APIs as well as features that are only available through the library APIs. Each Support Library is backward-compatible to a specific Android API level. This design means that your applications can use the libraries' features and still be compatible with devices running Android 1.6 (API level 4) and up." />

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

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

<android.support.design.widget.FloatingActionButton
    android:layout_height="wrap_content"
    android:layout_width="wrap_content"
    app:layout_anchor="@id/cv"
    app:layout_anchorGravity="right|end|bottom"
    android:layout_marginRight="32dp"
    android:clickable="true"/>

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

Answer 3

将整个布局包装在 CoordinatorLayout 中，并将您的锚点定义到卡片视图。

app:layout_anchor="@id/card_view"
app:layout_anchorGravity="bottom|end|right"

那么它应该可以工作了。