按钮不显示在Android Studio中的RecycleView下方

Question

设计布局RecycleView用于显示图像.下面添加了一个按钮RecycleView以保存列表中的所选项目.在设计视图中和运行应用程序时,按钮不可见.无法追踪问题所在.代码是:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
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:orientation="vertical"
android:fitsSystemWindows="true"
tools:context="com.example.user.recycleview.imagesview">

<android.support.design.widget.AppBarLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginBottom="4dp"
    android:theme="@style/AppTheme.AppBarLayout">

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

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

<view
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    class="android.support.v7.widget.RecyclerView"
    android:id="@+id/recycler_view" />

<Button
    android:id="@+id/button7"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_gravity="center_horizontal"
    android:background="@drawable/savebutton"
    android:text="@string/save"
    android:textColor="@color/white"
    android:textSize="12pt" />


<!--
Deleted fab element
-->

</LinearLayout>

Answer 1

1.添加RelativeLayout下面AppBarLayout,把Button和RecyclerView里面RelativeLayout.

2.添加属性android:layout_alignParentBottom="true"以Button在bottom屏幕上对齐它.

3.添加属性android:layout_above="@id/button7"以RecyclerView显示上面的内容Button.

更新您的布局如下:

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

    <android.support.design.widget.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="4dp"
        android:theme="@style/AppTheme.AppBarLayout">

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

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

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

        <Button
            android:id="@+id/button7"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:text="Save"
            android:textColor="@android:color/black" />

        <android.support.v7.widget.RecyclerView
            android:id="@+id/recycler_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_above="@id/button7"/>

    </RelativeLayout>
</LinearLayout>

OUTPUT: