BottomNavigationView+viewpager动态设置底部导航栏

最近做毕设，要实现底部导航栏随不同角色登录改变，用了一整个下午完成，所以写个笔记供读者阅览。

---

一.实现过程

1.导包(AS创建项目自带)

 implementation 'com.google.android.material:material:1.1.0'

2.xml文件

如果仅实现静态的导航栏，则直接添加app:menu(没有CustomViewPager，可以直接用ViewPager)

<com.ssa.seniorabilityassessment.CustomViewPager
        android:id="@+id/viewpager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@+id/bottom_navigation"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginBottom="1dp"
        android:layout_alignParentLeft="true" />

    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/bottom_navigation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:background="@color/white"
        app:itemIconTint="@drawable/bottom_navigation_selector"
        app:itemTextColor="@drawable/bottom_navigation_selector"
         />

menu中的内容：

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:id="@+id/item_home"
        android:icon="@drawable/ic_baseline_home_24"
        android:title="首页" />
    <item
        android:id="@+id/item_lib"
        android:icon="@drawable/ic_baseline_explore_24"
        android:title="发现" />
    <item
        android:id="@+id/item_assess"
        android:icon="@drawable/ic_baseline_location_on_24"
        android:title="导航" />

    <item
        android:id="@+id/item_person"
        android:icon="@drawable/ic_baseline_person_24"
        android:title="我的" />
</menu>

若使用动态的，需要把app:menu去掉，在activity中写。

3.Activity

①动态添加menu

   bottomNavigationView.getMenu().add(0, 0, 0, "首页");
   bottomNavigationView.getMenu().findItem(0).setIcon(R.drawable.ic_baseline_home_24);

②设置监听BottomNavigationView点击事件

        bottomNavigationView.setOnNavigationItemSelectedListener(
                new BottomNavigationView.OnNavigationItemSelectedListener() {
                    @Override
                    public boolean onNavigationItemSelected(@NonNull MenuItem item) {
                        switch (item.getItemId()) {

                            case 0:
                                viewPager.setCurrentItem(0,false);
                                break;
                            case 1:
                                viewPager.setCurrentItem(1,false);
                                break;
                            case 2:
                                viewPager.setCurrentItem(2,false);
                                break;
                            case 3:
                                viewPager.setCurrentItem(3,false);
                                break;
                        }
                        return false;
                    }
                });

③创建并添加fragment

 //fragments列表
List<Fragment> fragmentList = new ArrayList<>();
//将fragment添加进去
 fragmentList.add(new PersonFragment());

④ViewPager监听

        viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                if (menuItem != null) {
                    menuItem.setChecked(false);
                } else {
                    bottomNavigationView.getMenu().getItem(0).setChecked(false);
                }
                menuItem = bottomNavigationView.getMenu().getItem(position);
                menuItem.setChecked(true);
            }
            @Override
            public void onPageScrollStateChanged(int state) {
            }
        });

⑤适配器（重要）

适配器要使用FragmentStatePagerAdapter不要使用FragmentPagerAdapter，使用FragmentPagerAdapter时，第一次进入各fragment页面都会正常显示，但是当你切换角色时，比如由四个菜单编程两个菜单时，会发现菜单与fragment内容不一致，这是由于第一次会正常调用FragmentPagerAdapter的getItem()的方法，之后返回进入都不会在调用，除非关闭整个最外层的Activity才进入才会正常显示；之所以没有调用是因为FragmentPagerAdapter中有缓存没有移除之前内部已经包含的fragment，所以我选择使用FragmentStatePagerAdapter来替换FragmentPagerAdapter，每次退出都是remove之前的Fragment

        ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager(),fragmentList);
        viewPager.setAdapter(adapter);

public class ViewPagerAdapter extends FragmentStatePagerAdapter {

    private List<Fragment> mFragmentList;
    private FragmentManager fm;
    public ViewPagerAdapter(FragmentManager manager,List<Fragment> fragmentList) {
        super(manager);
        fm = manager;
        mFragmentList = fragmentList;
    }

    @NotNull
    @Override
    public Fragment getItem(int position) {
        return mFragmentList.get(position);
    }

    @Override
    public int getCount() {
        return mFragmentList.size();
    }
}

---

 

二.遇到的问题

使用FragmentStatePagerAdapter，可能会导致页面变白，没有内容，我第一次使用的时候是按照不同角色在if判断条件中去添加menu，但是这样运行后会导致页面变白，所以需要直接把所有页面先add添加进去，然后那些不需要的menu直接隐藏掉。

---

三.完整代码

MainActivity

import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.MenuItem;
import android.view.View;
import android.widget.PopupMenu;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentTransaction;
import androidx.viewpager.widget.ViewPager;
import androidx.viewpager2.adapter.FragmentStateAdapter;


import com.ssa.seniorabilityassessment.fragment.AssessFragment;
import com.ssa.seniorabilityassessment.fragment.ChartFragment;
import com.ssa.seniorabilityassessment.fragment.HomeFragment;
import com.ssa.seniorabilityassessment.fragment.PersonFragment;
import com.google.android.material.bottomnavigation.BottomNavigationView;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

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

import static com.ssa.seniorabilityassessment.LoginActivity.LOGIN_OK;

public class MainActivity extends FragmentActivity {
    MenuItem menuItem;
    private List<Fragment> fragmentList;
    @RequiresApi(api = Build.VERSION_CODES.KITKAT)
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        try {
            initViewPager();
        } catch (JSONException e) {
            e.printStackTrace();
        }
    }
    @RequiresApi(api = Build.VERSION_CODES.KITKAT)
    public void initViewPager() throws JSONException {
        fragmentList = new ArrayList<>();
        BottomNavigationView bottomNavigationView = findViewById(R.id.bottom_navigation);;
        CustomViewPager viewPager;
        viewPager =  findViewById(R.id.viewpager);
        viewPager.setPagingEnabled(false);
        viewPager.setOffscreenPageLimit(4);
        //默认 >3 的选中效果会影响ViewPager的滑动切换时的效果，故利用反射去掉
        //BottomNavigationViewHelper.disableShiftMode(bottomNavigationView);

        SharedPreferences sp=getSharedPreferences("User",MODE_PRIVATE);
        if(bottomNavigationView.getMenu().size() != 0){
            bottomNavigationView.getMenu().clear();
        }
        //添加菜单
        bottomNavigationView.getMenu().add(0, 0, 0, "首页");
        bottomNavigationView.getMenu().findItem(0).setIcon(R.drawable.ic_baseline_home_24);

        bottomNavigationView.getMenu().add(0, 1, 1, "评估");
        bottomNavigationView.getMenu().findItem(1).setIcon(R.drawable.ic_baseline_explore_24);

        bottomNavigationView.getMenu().add(0, 2, 2, "数据中心");
        bottomNavigationView.getMenu().getItem(2).setIcon(R.drawable.ic_baseline_location_on_24);

        bottomNavigationView.getMenu().add(0,3, 3, "我的");
        bottomNavigationView.getMenu().getItem(3).setIcon(R.drawable.ic_baseline_person_24);

        fragmentList.add(new HomeFragment());
        if(sp.getString("data",null) != null){
            JSONObject jsonObject = new JSONObject(sp.getString("data",null));
            //按照不同角色添加fragment，隐藏菜单
            if(jsonObject.getString("role").equals("ROLE_USER")){
                bottomNavigationView.getMenu().removeItem(1);
                bottomNavigationView.getMenu().removeItem(2);
                fragmentList.add(new PersonFragment());
            }
            else if (jsonObject.getString("role").equals("ROLE_ASSESSOR")){
                fragmentList.add(new AssessFragment());
                fragmentList.add(new ChartFragment());
                fragmentList.add(new PersonFragment());
            }
            else if (jsonObject.getString("role").equals("ROLE_ADMIN")){
                fragmentList.add(new AssessFragment());
                fragmentList.add(new ChartFragment());
                fragmentList.add(new PersonFragment());
            }
            else {
                
                bottomNavigationView.getMenu().removeItem(1);
                bottomNavigationView.getMenu().removeItem(2);
                fragmentList.add(new PersonFragment());
            }
        }
        else{
            bottomNavigationView.getMenu().removeItem(1);
            bottomNavigationView.getMenu().removeItem(2);
            fragmentList.add(new PersonFragment());
        }
        /**
         * 监听BottomNavigationView点击事件
         */
        bottomNavigationView.setOnNavigationItemSelectedListener(
                new BottomNavigationView.OnNavigationItemSelectedListener() {
                    @Override
                    public boolean onNavigationItemSelected(@NonNull MenuItem item) {
                        switch (item.getItemId()) {

                            case 0:
                                viewPager.setCurrentItem(0,false);
                                break;
                            case 1:
                                viewPager.setCurrentItem(1,false);
                                break;
                            case 2:
                                viewPager.setCurrentItem(2,false);
                                break;
                            case 3:
                                viewPager.setCurrentItem(3,false);
                                break;
                        }
                        return false;
                    }
                });
        viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {

            }

            @Override
            public void onPageSelected(int position) {
                if (menuItem != null) {
                    menuItem.setChecked(false);
                } else {
                    bottomNavigationView.getMenu().getItem(0).setChecked(false);
                }
                menuItem = bottomNavigationView.getMenu().getItem(position);
                menuItem.setChecked(true);
            }
            @Override
            public void onPageScrollStateChanged(int state) {
            }
        });
        System.out.println(fragmentList);
        ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager(),fragmentList);
        viewPager.setAdapter(adapter);
    }

    @RequiresApi(api = Build.VERSION_CODES.KITKAT)
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (resultCode == LOGIN_OK) {
            try {
                initViewPager();
            } catch (JSONException e) {
                e.printStackTrace();
            }
        }
    }
}

ViewPagerAdapter

import android.content.Context;
import android.view.ViewGroup;

import androidx.annotation.NonNull;
import androidx.fragment.app.Fragment;
import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentPagerAdapter;
import androidx.fragment.app.FragmentStatePagerAdapter;
import androidx.fragment.app.FragmentTransaction;
import androidx.viewpager2.adapter.FragmentStateAdapter;

import org.jetbrains.annotations.NotNull;

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

public class ViewPagerAdapter extends FragmentStatePagerAdapter {

    private List<Fragment> mFragmentList;
    private FragmentManager fm;
    public ViewPagerAdapter(FragmentManager manager,List<Fragment> fragmentList) {
        super(manager);
        fm = manager;
        mFragmentList = fragmentList;
    }

    @NotNull
    @Override
    public Fragment getItem(int position) {
        return mFragmentList.get(position);
    }

    @Override
    public int getCount() {
        return mFragmentList.size();
    }
}

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:id="@+id/activity_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <com.ssa.seniorabilityassessment.CustomViewPager
        android:id="@+id/viewpager"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_above="@+id/bottom_navigation"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginBottom="1dp"
        android:layout_alignParentLeft="true" />

    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/bottom_navigation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentBottom="true"
        android:background="@color/white"
        app:itemIconTint="@drawable/bottom_navigation_selector"
        app:itemTextColor="@drawable/bottom_navigation_selector"
         />

    <View
        android:layout_width="match_parent"
        android:layout_height="5dp"
        android:layout_above="@id/bottom_navigation"
        android:background="@drawable/bottom_shadow" />

</RelativeLayout>

LoginActivity

package com.ssa.seniorabilityassessment;

import androidx.annotation.Nullable;
import androidx.annotation.RequiresApi;
import androidx.appcompat.app.AppCompatActivity;

import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Build;
import android.os.Bundle;
import android.os.Looper;
import android.util.Log;
import android.view.View;
import android.view.inputmethod.InputMethodManager;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import com.google.gson.Gson;
import com.ssa.seniorabilityassessment.entity.UserDTO;

import org.json.JSONException;
import org.json.JSONObject;

import java.util.Timer;
import java.util.TimerTask;
import java.util.regex.Pattern;

import okhttp3.FormBody;
import okhttp3.MediaType;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;

public class LoginActivity extends AppCompatActivity implements View.OnClickListener{
    private Button btn_login;
    private EditText et_account;
    private EditText et_password;
    public static final int LOGIN_OK = 3;
    SharedPreferences sp=null;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        initUI();
        initData();

    }
    public void initUI(){
        btn_login = findViewById(R.id.btn_login);
        et_account = findViewById(R.id.et_account);
        et_password = findViewById(R.id.et_password);


        et_account.setFocusable(true);
        et_account.setFocusableInTouchMode(true);
        et_account.requestFocus();

        Timer timer =new Timer();
        timer.schedule(new TimerTask(){
            @Override
            public void run() {
                InputMethodManager inputManager=(InputMethodManager)getSystemService(Context.INPUT_METHOD_SERVICE);
                inputManager.showSoftInput(et_account,0);
            }}, 200);
        sp= getSharedPreferences("User",MODE_PRIVATE);
    }

    public void initData(){
        btn_login.setOnClickListener(this);
    }


    @Override
    public void onClick(View v) {
        Intent intent=new Intent();
        int id=v.getId();
        switch (id){
            case R.id.btn_back:
                finish();
                break;
//            case R.id.btn_register:
//                intent.setClass(LoginActivity.this,RegisterActivity.class);
//                startActivityForResult(intent,REG);
//                break;
//            case R.id.btn_forget:
//                intent.setClass(LoginActivity.this,ForgetActivity.class);
//                startActivityForResult(intent,FOG);
//                break;
            case R.id.btn_login:
                String account=et_account.getText().toString().trim();
                String password=et_password.getText().toString();
                if(account.length()==0){
                    Toast.makeText(LoginActivity.this,"用户名不能为空",Toast.LENGTH_SHORT).show();
                    return;
                }
                if(password.length()==0){
                    Toast.makeText(LoginActivity.this,"密码不能为空",Toast.LENGTH_SHORT).show();
                    return;
                }
                new Thread(){
                    @RequiresApi(api = Build.VERSION_CODES.KITKAT)
                    @Override
                    public void run() {
                        super.run();
                        Looper.prepare();
                        try {
                            //调用后端接口，设置参数
                            JSONObject jsonUser = new JSONObject();
                            jsonUser.put("username",account);
                            jsonUser.put("password",password);
                            //发送请求，可以使用默认的http，这里使用okhttp请求
                            OkHttpClient client = new OkHttpClient();//创建client对象
                            //发送请求
                            Request request = new Request.Builder()
                                    .url("xxxxxxxxxxxxx")
                                    .post(RequestBody.Companion.create(jsonUser.toString(), MediaType.Companion.parse("application/json;charset=utf-8")))
                                    .build();
                            Response response = client.newCall(request).execute();//执行发送的指令，并接收后端接口返回的数据
                            String responseData = response.body().string();//获取返回过来的json格式结果
                            JSONObject jsonObject = new JSONObject(responseData);
                            if(jsonObject.getString("code").equals("200")){
                                //存储手机号和姓名，方便调用
                                SharedPreferences.Editor edit=sp.edit();
                                edit.clear();
                                edit.putString("data",jsonObject.getString("data"));
                                edit.putString("avatar",new JSONObject(jsonObject.getString("data")).getString("avatarUrl"));
                                edit.commit();
                                //intent.setClass(LoginActivity.this,MainActivity.class);
                                intent.putExtra("data",jsonObject.getString("data"));
                                intent.putExtra("avatar",new JSONObject(jsonObject.getString("data")).getString("avatarUrl"));
                                System.out.println("登录"+jsonObject.getString("data"));
                                //startActivity(intent);
                                setResult(LOGIN_OK, intent);
                                finish();
                                runOnUiThread(new Runnable() {
                                    @Override
                                    public void run() {
                                        //操作安卓界面不能在单线程中，只能在主线程中，所以使用runOnUiThread中操作ui
                                        Toast.makeText(LoginActivity.this,"登录成功", Toast.LENGTH_SHORT).show();
                                    }
                                });
                            }
                            else{
                                runOnUiThread(new Runnable() {
                                    @Override
                                    public void run() {
                                        //操作安卓界面不能在单线程中，只能在主线程中，所以使用runOnUiThread中操作ui
                                        try {
                                            Toast.makeText(LoginActivity.this,jsonObject.getString("msg"), Toast.LENGTH_SHORT).show();
                                        } catch (JSONException e) {
                                            e.printStackTrace();
                                        }
                                    }
                                });
                            }
                        }catch (Exception e){
                            e.printStackTrace();
                        }
                        Looper.loop();
                    }
                }.start();
                break;
        }
    }
    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (resultCode==8) {
            et_account.setFocusable(true);
            et_account.setFocusableInTouchMode(true);
            et_account.requestFocus();
            Timer timer = new Timer();
            timer.schedule(new TimerTask() {
                @Override
                public void run() {
                    InputMethodManager inputManager = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);
                    inputManager.showSoftInput(et_account, 0);
                }
            }, 200);
        }
    }
}

Fragment(例子)

package com.ssa.seniorabilityassessment.fragment;

import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;

import androidx.fragment.app.Fragment;
import androidx.viewpager.widget.PagerAdapter;
import androidx.viewpager.widget.ViewPager;

import com.ssa.seniorabilityassessment.R;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

public class HomeFragment extends Fragment implements View.OnClickListener{
    private View root;
    private ViewPager mViewPaper;
    private List<ImageView> images;
    private List<View> dots;
    private int currentItem;
    //记录上一次点的位置
    private int oldPosition = 0;
    //存放图片的id
    private int[] imageIds = new int[]{
            R.mipmap.ic_main1,
            R.mipmap.ic_main2
    };
    private ViewPagerAdapter adapter;
    private ScheduledExecutorService scheduledExecutorService;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        root=inflater.inflate(R.layout.fragment_home, container, false);
        initUI();
        initData();
        return root;
    }

    @Override
    public void onResume() {
        super.onResume();
        initData1();
    }

    @Override
    public void onHiddenChanged(boolean hidden) {
        // TODO Auto-generated method stub
        super.onHiddenChanged(hidden);
        initData1();
    }

    private void initData1(){
    }
    private void initUI(){
        mViewPaper = root.findViewById(R.id.vp);


        //显示的图片
        images = new ArrayList<ImageView>();
        for(int i = 0; i < imageIds.length; i++){
            ImageView imageView = new ImageView(getActivity());
            imageView.setBackgroundResource(imageIds[i]);
            images.add(imageView);
        }
        //显示的小点
        dots = new ArrayList<View>();
        dots.add(root.findViewById(R.id.dot_0));
        dots.add(root.findViewById(R.id.dot_1));
        adapter = new ViewPagerAdapter();
        mViewPaper.setAdapter(adapter);

        mViewPaper.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
            @Override
            public void onPageSelected(int position) {
                dots.get(position).setBackgroundColor(getResources().getColor(R.color.blue));
                dots.get(oldPosition).setBackgroundColor(getResources().getColor(R.color.grey1));

                oldPosition = position;
                currentItem = position;
            }

            @Override
            public void onPageScrolled(int arg0, float arg1, int arg2) {

            }

            @Override
            public void onPageScrollStateChanged(int arg0) {

            }
        });
    }
    private void initData(){
      //  btn_assess.setOnClickListener(this);
      //  btn_info.setOnClickListener(this);
      //  btn_senior.setOnClickListener(this);
    }
    @Override
    public void onClick(View v) {
        int id=v.getId();
        Intent intent=new Intent();
        switch (id){
//            case R.id.tv_login:
//                if(sp.getString("phone",null)!=null){
//                    return;
//                }
        }
    }
    /*定义的适配器*/
    public class ViewPagerAdapter extends PagerAdapter {

        @Override
        public int getCount() {
            return images.size();
        }

        @Override
        public boolean isViewFromObject(View arg0, Object arg1) {
            return arg0 == arg1;
        }

        @Override
        public void destroyItem(ViewGroup view, int position, Object object) {
            // TODO Auto-generated method stub
//          super.destroyItem(container, position, object);
//          view.removeView(view.getChildAt(position));
//          view.removeViewAt(position);
            view.removeView(images.get(position));
        }

        @Override
        public Object instantiateItem(ViewGroup view, int position) {
            // TODO Auto-generated method stub
            view.addView(images.get(position));
            return images.get(position);
        }

    }

    /**
     * 利用线程池定时执行动画轮播
     */
    @Override
    public void onStart() {
        // TODO Auto-generated method stub
        super.onStart();
        scheduledExecutorService = Executors.newSingleThreadScheduledExecutor();
        scheduledExecutorService.scheduleWithFixedDelay(
                new ViewPageTask(),
                2,
                2,
                TimeUnit.SECONDS);
    }


    /**
     * 图片轮播任务
     * @author liuyazhuang
     *
     */
    private class ViewPageTask implements Runnable{

        @Override
        public void run() {
            currentItem = (currentItem + 1) % imageIds.length;
            mHandler.sendEmptyMessage(0);
        }
    }

    /**
     * 接收子线程传递过来的数据
     */
    private Handler mHandler = new Handler(){
        public void handleMessage(android.os.Message msg) {
            mViewPaper.setCurrentItem(currentItem);
        };
    };
    @Override
    public void onStop() {
        // TODO Auto-generated method stub
        super.onStop();
        if(scheduledExecutorService != null){
            scheduledExecutorService.shutdown();
            scheduledExecutorService = null;
        }
    }

}

四.页面效果