activity_main.xml

<?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="match_parent"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin">

    <Button
        android:id="@+id/btn_camera_take_photo"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="拍照保存实现" />

    <Button
        android:id="@+id/btn_animation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/android_animation" />

    <Button
        android:id="@+id/btn_animator"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/android_animator" />

    <Button
        android:id="@+id/btn_day_night"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/day_night_mode" />

</LinearLayout>