今天新建Android Studio项目的时候,发现一个微妙的变化:
看完心情是这样的:
这个什么东西:
BottomNavigationView
来看看吧,小伙伴们:
先看它的布局文件:
<android.support.design.widget.BottomNavigationView
android:id="@+id/navigation"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:background="?android:attr/windowBackground"
app:menu="@menu/navigation" />
app:menu 一定是我们的菜单,来看看:
<?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="@drawable/ic_home_black_24dp"
android:title="@string/title_home" />
<item
android:id="@+id/navigation_dashboard"
android:icon="@drawable/ic_dashboard_black_24dp"
android:title="@string/title_dashboard" />
<item
android:id="@+id/navigation_notifications"
android:icon="@drawable/ic_notifications_black_24dp"
android:title="@string/title_notifications" />
</menu>
果然如此。那么在MainActivity中,它是怎么使用的呢?
public class MainActivity extends AppCompatActivity {
private TextView mTextMessage;
private BottomNavigationView.OnNavigationItemSelectedListener mOnNavigationItemSelectedListener
= new BottomNavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.navigation_home:
mTextMessage.setText(R.string.title_home);
return true;
case R.id.navigation_dashboard:
mTextMessage.setText(R.string.title_dashboard);
return true;
case R.id.navigation_notifications:
mTextMessage.setText(R.string.title_notifications);
return true;
}
return false;
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mTextMessage = (TextView) findViewById(R.id.message);
BottomNavigationView navigation = (BottomNavigationView) findViewById(R.id.navigation);
navigation.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);
}
}
哈哈,以后底部导航栏就可以放大招啦!