本程式只有一個Activity，首先載入activity_main佈局檔案。通過點選不同的按鈕，分別載入不同的佈局檔案layout_1、layout_2、layout_3。

   activity_main.xml檔案如下：

<?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"
    tools:context="com.horrorkwangmail.a20171208_multilayout.ActivityMain">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:text="This is Layout main"
        android:textAllCaps="false"
        android:textSize="25sp"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>

    <Button
        android:id="@+id/buttonLayout1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="40dp"
        android:text="Layout 1"
        android:textAllCaps="false"
        app:layout_constraintEnd_toStartOf="@+id/buttonLayout2"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView"
        android:onClick="buttonClick"/>

    <Button
        android:id="@+id/buttonLayout2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:layout_marginTop="8dp"
        android:text="Layout 2"
        android:textAllCaps="false"
        app:layout_constraintBottom_toBottomOf="@+id/buttonLayout1"
        app:layout_constraintEnd_toStartOf="@+id/buttonLayout3"
        app:layout_constraintStart_toEndOf="@+id/buttonLayout1"
        app:layout_constraintTop_toTopOf="@+id/buttonLayout1"
        android:onClick="buttonClick"/>

    <Button
        android:id="@+id/buttonLayout3"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Layout 3"
        android:textAllCaps="false"
        app:layout_constraintBottom_toBottomOf="@+id/buttonLayout2"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toEndOf="@+id/buttonLayout2"
        app:layout_constraintTop_toTopOf="@+id/buttonLayout2"
        android:onClick="buttonClick"/>

</android.support.constraint.ConstraintLayout>
 

<?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">

    <Button
        android:id="@+id/buttonBack"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:text="Back to Layout main"
        android:textAllCaps="false"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="30dp"
        android:text="This is Layout 1"
        android:textSize="25sp"
        android:textAllCaps="false"
        app:layout_constraintBottom_toTopOf="@+id/buttonBack"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>

</android.support.constraint.ConstraintLayout>
 

<?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">

    <Button
        android:id="@+id/buttonBack"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:text="Back to Layout main"
        android:textAllCaps="false"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="30dp"
        android:text="This is Layout 2"
        android:textSize="25sp"
        android:textAllCaps="false"
        app:layout_constraintBottom_toTopOf="@+id/buttonBack"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>

</android.support.constraint.ConstraintLayout>
 

<?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">

    <Button
        android:id="@+id/buttonBack"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="8dp"
        android:text="Back to Layout main"
        android:textAllCaps="false"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:layout_marginEnd="8dp"
        android:layout_marginStart="8dp"
        android:layout_marginTop="30dp"
        android:text="This is Layout 3"
        android:textSize="25sp"
        android:textAllCaps="false"
        app:layout_constraintBottom_toTopOf="@+id/buttonBack"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"/>

</android.support.constraint.ConstraintLayout>

strings.xml檔案如下：

<resources>
    <string name="app_name">MultiLayout</string>
    <string name="layoutMain">Layout main</string>
    <string name="layout1">Layout 1</string>
    <string name="layout2">Layout 2</string>
    <string name="layout3">Layout 3</string>
</resources>

package com.horrorkwangmail.a20171208_multilayout;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class ActivityMain extends AppCompatActivity
{

    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);  //首先載入activity_main佈局檔案
        this.setTitle(R.string.layoutMain);  //設定標題欄名稱
    }


    public void buttonClick(View v)
    {
        switch (v.getId())
        {
            case R.id.buttonLayout1:
                setContentView(R.layout.layout_1);  //載入layout_1佈局檔案
                this.setTitle(R.string.layout1);  //設定標題欄名稱

                //點選按鈕，回到activity_main佈局檔案
                //並設定標題欄名稱
                Button buttonBack1=findViewById(R.id.buttonBack);
                buttonBack1.setOnClickListener(new View.OnClickListener()
                {
                    @Override
                    public void onClick(View view)
                    {
                        setContentView(R.layout.activity_main);
                        setTitle(R.string.layoutMain);
                    }
                });
                break;
            case R.id.buttonLayout2:
                setContentView(R.layout.layout_2);  //載入layout_2佈局檔案
                this.setTitle(R.string.layout2);  //設定標題欄名稱

                //點選按鈕，回到activity_main佈局檔案
                //並設定標題欄名稱
                Button buttonBack2=findViewById(R.id.buttonBack);
                buttonBack2.setOnClickListener(new View.OnClickListener()
                {
                    @Override
                    public void onClick(View view)
                    {
                        setContentView(R.layout.activity_main);
                        setTitle(R.string.layoutMain);
                    }
                });
                break;
            case R.id.buttonLayout3:
                setContentView(R.layout.layout_3);  //載入layout_3佈局檔案
                this.setTitle(R.string.layout3);  //設定標題欄名稱

                //點選按鈕，回到activity_main佈局檔案
                //並設定標題欄名稱
                Button buttonBack3=findViewById(R.id.buttonBack);
                buttonBack3.setOnClickListener(new View.OnClickListener()
                {
                    @Override
                    public void onClick(View view)
                    {
                        setContentView(R.layout.activity_main);
                        setTitle(R.string.layoutMain);
                    }
                });
                break;
            default:
                break;
        }
    }
    
    
}

真機測試如下：