PopupMenu

第一步：建一个资源文件 menu.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android" >
    
    <item android:id="@+id/menu_1"
        android:title="@string/menu_1" />
    
    <item android:id="@+id/menu_2"
        android:title="@string/menu_3" />
    
</menu>

第二步 写代码

onCreate事件代码

        BottomNavigationView navigation = (BottomNavigationView) findViewById(R.id.navigation);
        navigation.setOnNavigationItemSelectedListener(mOnNavigationItemSelectedListener);
        BottomNavigationItemView naviItem = (BottomNavigationItemView)findViewById(R.id.navigation_dashboard) ;

        mPopupMenu = new PopupMenu(this,naviItem);
        mPopupMenu.inflate(R.menu.menu); //两种inflate方式都可以
//        mPopupMenu.getMenuInflater().inflate(R.menu.navigation, mPopupMenu.getMenu());
        mPopupMenu.setOnMenuItemClickListener(new PopupMenu.OnMenuItemClickListener(){
            @Override
            public boolean onMenuItemClick(MenuItem item) {
                Toast.makeText(getApplicationContext(), "这个是PopupMenu的演示demo", Toast.LENGTH_LONG).show();
                return true;
            }
        });

BottomNavigationView.OnNavigationItemSelectedListener事件

mPopupMenu.setGravity(Gravity.END); //设置显示的位置
mPopupMenu.show();