如何在 Android 应用程序中为整个屏幕添加边框?

How to put borders to the entire screen in the Android application?

我希望能够在我的应用程序的整个屏幕上放置边框,如下所示:

这怎么可能实现?

已更新示例(API 21 岁或以上):

第 1 步:

按如下方式在您的可绘制资源中创建边框 xml,

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

    <item><layer-list>
        <item>
            <shape>
                <stroke android:width="4dp" android:color="#FF3B3B"/>
                <solid android:color="@android:color/transparent"/>
            </shape>
        </item>
    </layer-list>
    </item>

</selector>

第 2 步:

修改activity中的主题styles.xml设置状态栏颜色为透明如下,

<style name="AppTheme" parent="Theme.AppCompat.NoActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
        <item name="android:statusBarColor">@android:color/transparent</item>
    </style>

第 3 步:

为您的 activity xml 使用自定义工具栏,

<?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"
    android:background="@drawable/border"
    tools:context=".MainActivity">

    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_marginRight="4dp"
        android:layout_marginStart="4dp"
        android:layout_marginLeft="4dp"
        android:layout_marginEnd="4dp"
        android:layout_marginTop="4dp"
        app:layout_constraintTop_toTopOf="parent"
        app:contentInsetLeft="0dp"
        app:contentInsetStart="0dp"
        app:contentInsetRight="0dp"
        app:contentInsetEnd="0dp"
        android:layout_height="wrap_content">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="@color/colorPrimary"
            android:orientation="vertical">
            <ImageView
                android:background="@color/colorPrimaryDark"
                android:layout_width="match_parent"
                android:layout_height="24dp" />
            <TextView
                android:text="@string/app_name"
                android:textStyle="bold"
                android:textSize="16sp"
                android:textColor="#FFF"
                android:gravity="center_vertical"
                android:layout_width="match_parent"
                android:layout_marginStart="16dp"
                android:layout_height="?attr/actionBarSize" />

        </LinearLayout>
    </android.support.v7.widget.Toolbar>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</android.support.constraint.ConstraintLayout>

第 4 步:

最后,在您的 onCreateMethod 活动中,

 @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        getWindow().getDecorView().setSystemUiVisibility(
                View.SYSTEM_UI_FLAG_LAYOUT_STABLE
                        | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN);

    }

这是一个示例输出: