如何使用约束布局创建浮动操作按钮菜单？

Question

我如何制作浮动按钮菜单，两个按钮作为孩子，一个作为主要。目前，我只能制作一个浮动按钮。

基本上我将CoordinatorLayout结合起来以获取AppBarLayout和ConstraintLayout作为内容。

名为activity_incoming_lokal.xml的CoordinatorLayout如下所示：

<?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"
tools:context=".IncomingLokalActivity">

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

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

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

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

而对于内容看起来像这样

<?xml version="1.0" encoding="utf-8"?>    <android.support.constraint.ConstraintLayout 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"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context=".IncomingLokalActivity"
tools:showIn="@layout/activity_incoming_lokal"
>

<EditText
    android:id="@+id/incomingLokalNomorKendaraan"
    android:layout_width="0dp"
    android:layout_height="wrap_content"
    android:layout_marginStart="8dp"
    android:layout_marginLeft="8dp"
    android:layout_marginTop="8dp"
    android:layout_marginEnd="8dp"
    android:layout_marginRight="8dp"
    android:layout_marginBottom="8dp"
    android:ems="10"
    android:hint="@string/nomor_plat_kendaraan"
    android:inputType="textPersonName"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toTopOf="parent"
    app:layout_constraintVertical_bias="0.0"
    android:autofillHints="@string/nomor_plat_kendaraan" />
</android.support.constraint.ConstraintLayout>

Answer 1

试试这个吧

    <android.support.design.widget.FloatingActionButton
    android:id="@+id/fab"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_margin="@dimen/fab_margin"
    app:srcCompat="@android:drawable/ic_input_add"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintBottom_toBottomOf="parent"
    />

Answer 2

app:layout_constraintRight_toLeftOf="parent"
   app:layout_constraintBottom_toTopOf="parent"

这将在功能上将FAB的右下角定位在屏幕的左上角。换句话说，您已将FAB限制在屏幕外。

很有可能你意味着你希望FAB的右边位于屏幕的右边，而FAB的底部位于屏幕的底部。所以请改用它们：

app:layout_constraintRight_toRightOf="parent"
app:layout_constraintBottom_toBottomOf="parent"

Answer 3

我决定将FAB移到内容中。所以。我的代码看起来像这样

<?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"
tools:context=".IncomingLokalActivity">

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

<include layout="@layout/content_incoming_lokal" />
</android.support.design.widget.CoordinatorLayout>

内容看起来像这样，

<?xml version="1.0" encoding="utf-8"?>    <android.support.constraint.ConstraintLayout 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"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
tools:context=".IncomingLokalActivity"
tools:showIn="@layout/activity_incoming_lokal"
>

<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginBottom="8dp"
    android:layout_marginRight="8dp"
    android:layout_marginEnd="8dp"
    android:orientation="vertical"
    app:layout_constraintRight_toRightOf="parent"
    app:layout_constraintBottom_toBottomOf="parent"
    android:gravity="center_horizontal"
>

    <android.support.design.widget.FloatingActionButton
        app:backgroundTint="@android:color/holo_blue_dark"
        android:id="@+id/fabUpload"
        android:layout_width="411dp"
        android:layout_height="wrap_content"
        android:layout_margin="4dp"
        app:srcCompat="@android:drawable/ic_menu_upload"
        android:tint="@android:color/white"
        app:fabSize="normal" />

    <android.support.design.widget.FloatingActionButton
        app:backgroundTint="@android:color/black"
        android:id="@+id/fabGallery"
        android:layout_width="411dp"
        android:layout_height="wrap_content"
        android:layout_margin="4dp"
        app:srcCompat="@android:drawable/ic_menu_gallery"
        android:tint="@android:color/white"
        app:fabSize="normal" />

    <android.support.design.widget.FloatingActionButton
        app:backgroundTint="@android:color/holo_red_light"
        android:id="@+id/fabCamera"
        android:layout_width="411dp"
        android:layout_margin="4dp"
        android:layout_height="wrap_content"
        app:srcCompat="@android:drawable/ic_menu_camera"
        android:tint="@android:color/white"
        app:fabSize="normal" />

    <android.support.design.widget.FloatingActionButton
        android:background="@color/tealGreen"
        app:backgroundTint="@color/tealGreen"
        android:id="@+id/fabMain"
        android:layout_width="411dp"
        android:layout_height="wrap_content"
        app:fabSize="normal"
        app:srcCompat="@android:drawable/ic_input_add"
        android:tint="@color/white"
        android:layout_margin="4dp"
    />
</LinearLayout>
</android.support.constraint.ConstraintLayout>