[Android] Android common layout xml code

The common layout of Android, the upper left corner, the upper right corner and the lower row.
Effect:

Code (there may be redundant and insufficient):

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="horizontal">
    <LinearLayout
        android:id="@+id/f1_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="horizontal">
    <LinearLayout
        android:id="@+id/f2_container"
        android:orientation="vertical"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_alignParentTop="true"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:gravity = "left">
    <Button
        android:id="@+id/button_1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="按钮1"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />
    <Button
        android:id="@+id/button_2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="按钮2"
        android:layout_below="@+id/button_1"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true" />
    </LinearLayout>
    <LinearLayout
        android:id="@+id/f3_container"
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
    <Button
        android:id="@+id/button_3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="按钮3"
        android:layout_gravity= "top|right"
        android:layout_alignParentRight="true"/>
    </LinearLayout>
    </LinearLayout>

    <LinearLayout
        android:id="@+id/f4_container"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity = "center|bottom"
        xmlns:android="http://schemas.android.com/apk/res/android">
        <Button
            android:id="@+id/button_M"
            android:layout_width="wrap_content"
            android:layout_height="60dp"
            android:text="功能1"
            android:layout_weight="1"/>
        <Button
            android:id="@+id/button_S"
            android:layout_width="wrap_content"
            android:layout_height="80dp"
            android:text="功能2"
            android:layout_weight="1"/>
        <Button
            android:id="@+id/button_G"
            android:layout_width="wrap_content"
            android:layout_height="60dp"
            android:text="功能3"
            android:layout_weight="1"/>
    </LinearLayout>

</RelativeLayout>

The reason why the “cannot resolve symbol'R'” that made me bald for an hour is that android:orientation=“horizontal” in the RelativeLayout was written as vertical at the beginning, and there should always be error messages under the xml but I didn’t pay attention. So the newly created files are all red, it's really a shame/funny face. I don't know why it's not vertical/funny face