toolbar+tablayout和标题联动（标题居中）

一、 getView是个视图 tab也是个视图

代码：

 	    toolbar.setTitle("");
        setSupportActionBar(toolbar);
        ActionBarDrawerToggle actionBarDrawerToggle = new ActionBarDrawerToggle(this, drawerlayout, toolbar, R.string.open, R.string.close);
        drawerlayout.addDrawerListener(actionBarDrawerToggle);
        actionBarDrawerToggle.syncState();
        //侧滑图片显示
        navigation.setItemIconTintList(null);

        drawerlayout.addDrawerListener(new DrawerLayout.DrawerListener() {
            @Override
            public void onDrawerSlide(@NonNull View view, float v) {
                int length = navigation.getRight();
                content.setX(length);
            }

            @Override
            public void onDrawerOpened(@NonNull View view) {

            }

            @Override
            public void onDrawerClosed(@NonNull View view) {

            }

            @Override
            public void onDrawerStateChanged(int i) {

            }
        });
        
        View headerView = navigation.getHeaderView(0);
        header = headerView.findViewById(R.id.header);
        header.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                drawerlayout.closeDrawer(Gravity.LEFT);
            }
        });

        header.setOnLongClickListener(new View.OnLongClickListener() {
            @Override
            public boolean onLongClick(View v) {
                Intent intent = new Intent(Intent.ACTION_PICK, MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                startActivityForResult(intent, 200);
                return false;
            }
        });

        navigation.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
            @Override
            public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {
                switch (menuItem.getItemId()) {
                    case R.id.one:
                    //通知
                        Toast.makeText(MainActivity.this, "已发送通知，请注意查收", Toast.LENGTH_SHORT).show();
                        NotificationManager notificationManager = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
                        if (Build.VERSION.SDK_INT > 26) {
                            NotificationChannel notificationChannel = new NotificationChannel("id", "name", NotificationManager.IMPORTANCE_DEFAULT);
                            notificationManager.createNotificationChannel(notificationChannel);
                        }
                        Notification build = new NotificationCompat.Builder(MainActivity.this, "id")
                                .setSmallIcon(R.drawable.chat)
                                .setContentTitle("通知")
                                .setContentText("")
                                .build();
                        notificationManager.notify(100, build);

                        break;
                    case R.id.five:
                        if (menuItem.getTitle().equals("日间模式")) {
                            navigation.setBackgroundColor(0);
                            drawerlayout.setBackgroundColor(R.drawable.cart);
                            menuItem.setTitle("夜间模式");
                        } else if (menuItem.getTitle().equals("夜间模式")) {
                            navigation.setBackgroundColor(-1);
                            drawerlayout.setBackgroundColor(0);
                            menuItem.setTitle("日间模式");
                        }
                        break;
                }
                return false;
            }
        });
  ArrayList<Fragment> fragments = new ArrayList<>();
        fragments.add(new HomeFragment());
        fragments.add(new ShiWuFragment());
        fragments.add(new MyFragment());
        fragments.add(new CollectFragment());
        fragments.add(new ProjectFragment());
        viewpager.setAdapter(new MainAdapter(getSupportFragmentManager(), fragments));
        tablayout.setupWithViewPager(viewpager);
        View home = getView(R.drawable.home_select, "首页");
        View home1 = getView(R.drawable.food_select, "食物");
        View home2 = getView(R.drawable.my_select, "我的");
        View home3 = getView(R.drawable.collect_select, "收藏");
        View home4 = getView(R.drawable.project_item, "项目");
        tablayout.getTabAt(0).setCustomView(home);
        tablayout.getTabAt(1).setCustomView(home1);
        tablayout.getTabAt(2).setCustomView(home2);
        tablayout.getTabAt(3).setCustomView(home3);
        tablayout.getTabAt(4).setCustomView(home4);

tablayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
    @Override
    public void onTabSelected(TabLayout.Tab tab) {

       TextView tv = tab.getCustomView().findViewById(R.id.title);
       tv_title.setText(tv.getText().toString());

    }

    @Override
    public void onTabUnselected(TabLayout.Tab tab) {

    }

    @Override
    public void onTabReselected(TabLayout.Tab tab) {

    }
});

private View getView(int select, String text) {
    View root = LayoutInflater.from(MainActivity.this).inflate(R.layout.tab_item, null);
    ImageView img = root.findViewById(R.id.img);
    TextView title = root.findViewById(R.id.title);
    img.setImageResource(select);
    title.setText(text);
    return root;
}

xml布局：

<android.support.v7.widget.Toolbar
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:id="@+id/toolbar">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_horizontal"    //在外面打出来，然后粘贴进来，有这个标题即可居中
        android:id="@+id/title"
        android:text="首页"
        android:textSize="25dp"
        />
</android.support.v7.widget.Toolbar>

toolbar.setTitle("");
title = (TextView) findViewById(R.id.title);
tablayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
    @Override
    public void onTabSelected(TabLayout.Tab tab) {
        if (tablayout.getTabAt(1).isSelected()) {

            title.setText("知识体系");   //setText

        } else if (tablayout.getTabAt(4).isSelected()) {

            title.setText("项目");
        }
    }

    @Override
    public void onTabUnselected(TabLayout.Tab tab) {

    }

    @Override
    public void onTabReselected(TabLayout.Tab tab) {

    }
});

二：如果用这种形式字体不能变色 用下面这种方法实现toolbar和tablayout联动

tablayout.getTabAt(0).setText("123").setIcon(R.drawable.konwledge_select);
tablayout.getTabAt(1).setText("456").setIcon(R.drawable.konwledge_select);
tablayout.getTabAt(2).setText("789").setIcon(R.drawable.konwledge_select);
tablayout.getTabAt(3).setText("147").setIcon(R.drawable.konwledge_select);
tablayout.getTabAt(4).setText("258").setIcon(R.drawable.konwledge_select);



tablayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
    @Override
    public void onTabSelected(TabLayout.Tab tab) {

        tv_title.setText(tab.getText().toString());

    }

    @Override
    public void onTabUnselected(TabLayout.Tab tab) {

    }

    @Override
    public void onTabReselected(TabLayout.Tab tab) {

    }
});

本文地址：https://blog.csdn.net/qq_46237697/article/details/107583884