[移动开发]十一、Android之SharedPreferences、引导页、登录页、选项菜单

前言

👨?💻👨?🌾📝记录学习成果，以便温故而知新

Gitee地址https://gitee.com/dycq/AppCode

项目目录

1.MainActivity

此页面没有界面，实现初始化跳转
首先判断是否进行过引导，然后判断是否登录

         SharedPreferences appSharedPreferences = getSharedPreferences("APP_DATA", MODE_PRIVATE);//apply才会写入到xml配置文件里面

        if(!appSharedPreferences.getBoolean("IS_GUIDE",  false)) {
            Intent intent = new Intent(MainActivity.this, GuideActivity.class);
            startActivity(intent);
            finish();
            return;
        }

        SharedPreferences userSharedPreferences = getSharedPreferences("USER_DATA", MODE_PRIVATE);

        if(!userSharedPreferences.getBoolean("IS_LOGIN",  false)) {
            Intent intent = new Intent(MainActivity.this, LoginActivity.class);
            startActivity(intent);
        } else {
            Intent intent = new Intent(MainActivity.this, AppActivity.class);
            startActivity(intent);
        }
        finish();

完整代码

package cn.fy.sharedpreferences;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;

import cn.fy.sharedpreferences.activity.AppActivity;
import cn.fy.sharedpreferences.activity.GuideActivity;
import cn.fy.sharedpreferences.activity.LoginActivity;

public class MainActivity extends AppCompatActivity {

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

        SharedPreferences appSharedPreferences = getSharedPreferences("APP_DATA", MODE_PRIVATE);
        //sp.edit().putString("userName", "Tom").apply();//apply才会写入到xml配置文件里面

        if(!appSharedPreferences.getBoolean("IS_GUIDE",  false)) {
            Intent intent = new Intent(MainActivity.this, GuideActivity.class);
            startActivity(intent);
            finish();
            return;
        }

        SharedPreferences userSharedPreferences = getSharedPreferences("USER_DATA", MODE_PRIVATE);

        if(!userSharedPreferences.getBoolean("IS_LOGIN",  false)) {
            Intent intent = new Intent(MainActivity.this, LoginActivity.class);
            startActivity(intent);
        } else {
            Intent intent = new Intent(MainActivity.this, AppActivity.class);
            startActivity(intent);
        }
        finish();
    }
}

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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=".MainActivity">

</androidx.constraintlayout.widget.ConstraintLayout>

2.引导页

（1）效果

点击“完成”完成引导功能

（2）GuideActivity

代码

package cn.fy.sharedpreferences.activity;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.fragment.app.Fragment;
import androidx.viewpager2.adapter.FragmentStateAdapter;

import android.os.Bundle;

import java.util.ArrayList;
import java.util.List;

import cn.fy.sharedpreferences.databinding.ActivityGuideBinding;
import cn.fy.sharedpreferences.fragment.Frag1Fragment;
import cn.fy.sharedpreferences.fragment.Frag2Fragment;
import cn.fy.sharedpreferences.fragment.Frag3Fragment;

public class GuideActivity extends AppCompatActivity {

    private ActivityGuideBinding binding;

    List<Class> fragmentList = new ArrayList<>();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //setContentView(R.layout.activity_guide);
        binding = ActivityGuideBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());


        fragmentList.add(Frag1Fragment.class);
        fragmentList.add(Frag2Fragment.class);
        fragmentList.add(Frag3Fragment.class);

        binding.vp.setAdapter(new FragmentStateAdapter(this) {
            @NonNull
            @Override
            public Fragment createFragment(int position) {
                try {
                    return (Fragment) fragmentList.get(position).newInstance();
                } catch (IllegalAccessException e) {
                    e.printStackTrace();
                } catch (InstantiationException e) {
                    e.printStackTrace();
                }
                return null;
            }

            @Override
            public int getItemCount() {
                return fragmentList.size();
            }
        });

    }
}

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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=".activity.GuideActivity">

    <androidx.viewpager2.widget.ViewPager2
        android:id="@+id/vp"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginStart="1dp"
        android:layout_marginTop="1dp"
        android:layout_marginEnd="1dp"
        android:layout_marginBottom="1dp"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

（3）3个Fragment

Frag1Fragment代码

package cn.fy.sharedpreferences.fragment;

import android.os.Bundle;

import androidx.fragment.app.Fragment;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import cn.fy.sharedpreferences.R;
import cn.fy.sharedpreferences.databinding.FragmentFrag1Binding;
import cn.fy.sharedpreferences.databinding.FragmentFrag3Binding;

/**
 * A simple {@link Fragment} subclass.
 * Use the {@link Frag1Fragment#newInstance} factory method to
 * create an instance of this fragment.
 */
public class Frag1Fragment extends Fragment {

    private FragmentFrag1Binding binding;

    // TODO: Rename parameter arguments, choose names that match
    // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";

    // TODO: Rename and change types of parameters
    private String mParam1;
    private String mParam2;

    public Frag1Fragment() {
        // Required empty public constructor
    }

    /**
     * Use this factory method to create a new instance of
     * this fragment using the provided parameters.
     *
     * @param param1 Parameter 1.
     * @param param2 Parameter 2.
     * @return A new instance of fragment Frag1Fragment.
     */
    // TODO: Rename and change types and number of parameters
    public static Frag1Fragment newInstance(String param1, String param2) {
        Frag1Fragment fragment = new Frag1Fragment();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        binding = FragmentFrag1Binding.inflate(inflater, container, false);
        binding.textView1.requestFocus();

        //return inflater.inflate(R.layout.fragment_frag1, container, false);
        return binding.getRoot();
    }
}

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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:id="@+id/frameLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".fragment.Frag1Fragment">

    <!-- TODO: Update blank fragment layout -->
    <TextView
        android:id="@+id/textView1"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="20dp"
        android:layout_marginTop="60dp"
        android:layout_marginEnd="20dp"
        android:text="地振高岗,一派溪山千古秀"
        android:textSize="20sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/textView4"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="20dp"
        android:layout_marginBottom="200dp"
        android:text="左划"
        android:textSize="20sp"
        android:textStyle="bold"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

Frag2Fragment代码

package cn.fy.sharedpreferences.fragment;

import android.os.Bundle;

import androidx.fragment.app.Fragment;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import cn.fy.sharedpreferences.R;

/**
 * A simple {@link Fragment} subclass.
 * Use the {@link Frag2Fragment#newInstance} factory method to
 * create an instance of this fragment.
 */
public class Frag2Fragment extends Fragment {

    // TODO: Rename parameter arguments, choose names that match
    // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";

    // TODO: Rename and change types of parameters
    private String mParam1;
    private String mParam2;

    public Frag2Fragment() {
        // Required empty public constructor
    }

    /**
     * Use this factory method to create a new instance of
     * this fragment using the provided parameters.
     *
     * @param param1 Parameter 1.
     * @param param2 Parameter 2.
     * @return A new instance of fragment Frag2Fragment.
     */
    // TODO: Rename and change types and number of parameters
    public static Frag2Fragment newInstance(String param1, String param2) {
        Frag2Fragment fragment = new Frag2Fragment();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.fragment_frag2, container, false);
    }
}

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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:id="@+id/frameLayout2"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".fragment.Frag2Fragment">

    <!-- TODO: Update blank fragment layout -->
    <TextView
        android:id="@+id/textView2"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="20dp"
        android:layout_marginTop="80dp"
        android:layout_marginEnd="20dp"
        android:text="门朝大海,三河合水万年流"
        android:textSize="20sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/textView5"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="20dp"
        android:layout_marginBottom="200dp"
        android:text="左划"
        android:textSize="20sp"
        android:textStyle="bold"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

Frag3Fragment代码

package cn.fy.sharedpreferences.fragment;

import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;

import androidx.fragment.app.Fragment;

import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Toast;

import cn.fy.sharedpreferences.MainActivity;
import cn.fy.sharedpreferences.R;
import cn.fy.sharedpreferences.databinding.FragmentFrag3Binding;

/**
 * A simple {@link Fragment} subclass.
 * Use the {@link Frag3Fragment#newInstance} factory method to
 * create an instance of this fragment.
 */
public class Frag3Fragment extends Fragment {

    private FragmentFrag3Binding binding;

    // TODO: Rename parameter arguments, choose names that match
    // the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
    private static final String ARG_PARAM1 = "param1";
    private static final String ARG_PARAM2 = "param2";

    // TODO: Rename and change types of parameters
    private String mParam1;
    private String mParam2;

    public Frag3Fragment() {
        // Required empty public constructor
    }

    /**
     * Use this factory method to create a new instance of
     * this fragment using the provided parameters.
     *
     * @param param1 Parameter 1.
     * @param param2 Parameter 2.
     * @return A new instance of fragment Frag3kFragment.
     */
    // TODO: Rename and change types and number of parameters
    public static Frag3Fragment newInstance(String param1, String param2) {
        Frag3Fragment fragment = new Frag3Fragment();
        Bundle args = new Bundle();
        args.putString(ARG_PARAM1, param1);
        args.putString(ARG_PARAM2, param2);
        fragment.setArguments(args);
        return fragment;
    }

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        if (getArguments() != null) {
            mParam1 = getArguments().getString(ARG_PARAM1);
            mParam2 = getArguments().getString(ARG_PARAM2);
        }
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        binding = FragmentFrag3Binding.inflate(inflater, container, false);

        binding.textView6.setClickable(true);
        binding.textView6.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                SharedPreferences appSharedPreferences = getActivity().getSharedPreferences("APP_DATA", Context.MODE_PRIVATE);
                appSharedPreferences.edit().putBoolean("IS_GUIDE", true).apply();
                Log.i(getClass().getName(), "textView6.setOnClickListener");

                Intent intent = new Intent(getActivity(), MainActivity.class);
                startActivity(intent);
                getActivity().finish();
            }
        });

        binding.textView7.setSelected(true);

        //return inflater.inflate(R.layout.fragment_frag3k, container, false);
        return binding.getRoot();
    }
}

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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:id="@+id/frameLayout3"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".fragment.Frag3Fragment">

    <!-- TODO: Update blank fragment layout -->
    <TextView
        android:id="@+id/textView3"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="20dp"
        android:layout_marginTop="100dp"
        android:layout_marginEnd="20dp"
        android:text="青木堂"
        android:textSize="20sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/textView6"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginEnd="20dp"
        android:layout_marginBottom="200dp"
        android:text="完成"
        android:textSize="20sp"
        android:textStyle="bold"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent" />

    <TextView
        android:id="@+id/textView7"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="20dp"
        android:layout_marginTop="80dp"
        android:layout_marginEnd="20dp"
        android:ellipsize="marquee"
        android:marqueeRepeatLimit="marquee_forever"
        android:singleLine="true"
        android:text="marquee实现效果，内容一定要超过文本框宽度"
        android:textColor="#673AB7"
        android:textSize="20sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/textView3" />

</androidx.constraintlayout.widget.ConstraintLayout>

（4）marquee

关键代码
fragment_frag3.xml

android:ellipsize="marquee"
android:marqueeRepeatLimit="marquee_forever"
android:singleLine="true"
android:text="marquee实现效果，内容一定要超过文本框宽度"

Frag3Fragment类onCreateView方法中

binding.textView7.setSelected(true);

3.登录页

效果
点击“登录”，实现登录操作，相关代码

SharedPreferences userSharedPreferences = getSharedPreferences("USER_DATA", MODE_PRIVATE);
userSharedPreferences.edit().putBoolean("IS_LOGIN", true).apply();

完整代码

package cn.fy.sharedpreferences.activity;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;

import cn.fy.sharedpreferences.databinding.ActivityLoginBinding;

public class LoginActivity extends AppCompatActivity {

    private ActivityLoginBinding binding;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //setContentView(R.layout.activity_login);
        binding = ActivityLoginBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());

        binding.btnReg.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Toast.makeText(LoginActivity.this, "功能未实现！！！", Toast.LENGTH_SHORT).show();
            }
        });

        binding.btnLogin.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                SharedPreferences userSharedPreferences = getSharedPreferences("USER_DATA", MODE_PRIVATE);
                userSharedPreferences.edit().putBoolean("IS_LOGIN", true).apply();

                Intent intent = new Intent(LoginActivity.this, AppActivity.class);
                startActivity(intent);
            }
        });
    }
}

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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=".activity.LoginActivity">

    <EditText
        android:id="@+id/txt_name"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="20dp"
        android:layout_marginTop="60dp"
        android:layout_marginEnd="20dp"
        android:ems="10"
        android:hint="请输入用户名"
        android:inputType="textPersonName"
        android:minHeight="48dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <EditText
        android:id="@+id/txt_pwd"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="20dp"
        android:layout_marginTop="40dp"
        android:layout_marginEnd="20dp"
        android:ems="10"
        android:hint="请输入密码"
        android:inputType="textPersonName"
        android:minHeight="48dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/txt_name" />

    <Button
        android:id="@+id/btn_reg"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="60dp"
        android:layout_marginTop="80dp"
        android:text="注册"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/txt_pwd" />

    <Button
        android:id="@+id/btn_login"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="80dp"
        android:layout_marginEnd="60dp"
        android:text="登录"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/txt_pwd" />
</androidx.constraintlayout.widget.ConstraintLayout>

4.应用页

效果
完整代码

package cn.fy.sharedpreferences.activity;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;

import android.app.Dialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;

import cn.fy.sharedpreferences.R;
import cn.fy.sharedpreferences.databinding.ActivityAppBinding;

public class AppActivity extends AppCompatActivity {

    private ActivityAppBinding binding;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        //setContentView(R.layout.activity_app);
        binding = ActivityAppBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_main_options, menu);
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(@NonNull MenuItem item) {
        switch (item.getItemId()) {
            case R.id.menu_main_options_exit:
                AlertDialog.Builder dialog = new AlertDialog.Builder(AppActivity.this);
                dialog.setTitle("请确定是否退出");
                dialog.setPositiveButton("确定", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {
                        Toast.makeText(AppActivity.this, "功能未实现！！！", Toast.LENGTH_SHORT).show();
                    }
                }).setNegativeButton("取消", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {

                    }
                }).show();
                break;
            default:
                break;
        }
        return super.onOptionsItemSelected(item);
    }
}

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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=".activity.AppActivity">

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="20dp"
        android:layout_marginTop="100dp"
        android:text="APP演示SharedPreferences"
        android:textSize="20sp"
        android:textStyle="bold"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

5.选项菜单

效果

（1）相关代码

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.menu_main_options, menu);
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(@NonNull MenuItem item) {
        switch (item.getItemId()) {
            case R.id.menu_main_options_exit:
                AlertDialog.Builder dialog = new AlertDialog.Builder(AppActivity.this);
                dialog.setTitle("请确定是否退出");
                dialog.setPositiveButton("确定", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {
                        Toast.makeText(AppActivity.this, "功能未实现！！！", Toast.LENGTH_SHORT).show();
                    }
                }).setNegativeButton("取消", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {

                    }
                }).show();
                break;
            default:
                break;
        }
        return super.onOptionsItemSelected(item);
    }

（2）菜单代码

建菜单请见三、Android导航篇中“建菜单bottom_navigation_menu”
menu_main_options.xml文件

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

    <item
        android:id="@+id/menu_main_options_exit"
        android:title="退出" />
</menu>

6.AndroidManifest.xml

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

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.AppCode">
        <activity
            android:name=".activity.GuideActivity"
            android:exported="false">
            <meta-data
                android:name="android.app.lib_name"
                android:value="" />
        </activity>
        <activity
            android:name=".activity.AppActivity"
            android:exported="false">
            <meta-data
                android:name="android.app.lib_name"
                android:value="" />
        </activity>
        <activity
            android:name=".activity.LoginActivity"
            android:exported="false">
            <meta-data
                android:name="android.app.lib_name"
                android:value="" />
        </activity>
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>

            <meta-data
                android:name="android.app.lib_name"
                android:value="" />
        </activity>
    </application>

</manifest>