BottomNavigationView

一、引入：

implementation 'com.google.android.material:material:1.0.0'

二、布局配置：

<com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/nav_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        app:menu="@menu/bottom_nav_menu" />

注：其中的app:menu="@menu/bottom_nav_menu"指向到相应的菜单配置文件上。

三、菜单配置文件

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

    <item
        android:id="@+id/navigation_home"
        android:icon="@android:drawable/ic_menu_camera"
        android:title="Home" />

    <item
        android:id="@+id/navigation_dashboard"
        android:icon="@android:drawable/ic_dialog_email"
        android:title="email" />

    <item
        android:id="@+id/navigation_notifications"
        android:icon="@android:drawable/ic_dialog_map"
        android:title="sss" />

</menu>

此时就可以看到相应的导航栏了

事件分配

        bottomNavigationView=findViewById(R.id.nav_view);
        bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
            @Override
            public boolean onNavigationItemSelected(@NonNull MenuItem item) {
                String title = item.getTitle().toString();
                switch (item.getItemId()) {
                    case R.id.navigation_home:
                        Toast.makeText(MainActivity.this,"Home",Toast.LENGTH_LONG).show();
                        break;
                    case R.id.navigation_dashboard:
                        Toast.makeText(MainActivity.this,"Dash",Toast.LENGTH_LONG).show();
                        break;
                    case R.id.navigation_notifications:
                        Toast.makeText(MainActivity.this,"notification",Toast.LENGTH_LONG).show();
                        break;
                }
                return true;
            }
        });