toolbar的使用

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <item
        android:id="@+id/addFriend"
        android:icon="@drawable/addfriend"
        android:orderInCategory="80"
        android:title="添加朋友"
        app:showAsAction="never" />
 
    <item
        android:id="@+id/newChat"
        android:icon="@drawable/morechat"
        android:orderInCategory="90"
        android:title="新建群聊"
        app:showAsAction="never" />
 
    <item
        android:id="@+id/scan"
        android:icon="@drawable/scan"
        android:orderInCategory="100"
        android:title="扫一扫"
        app:showAsAction="never"/>
    <item
        android:id="@+id/money"
        android:icon="@drawable/money"
        android:orderInCategory="100"
        android:title="收付款"
        app:showAsAction="never"/>
 
</menu>

        <androidx.appcompat.widget.Toolbar
            android:background="@color/blue"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_weight="1"
            android:id="@+id/toolbar"/>

setSupportActionBar(mMainBinding.toolbar); 不调用就不会显示toolbar
getSupportActionBar().setTitle("环信 app");  设置toolbar的标题
mMainBinding.toolbar.setOnMenuItemClickListener(listener); 设置监听器

   重写onCreateOptionsMenu 加载menu
@Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.toolbar, menu);
        return true;
    }

    重写onPrepareOptionsPanel 加载menu的图标
@Override
    protected boolean onPrepareOptionsPanel(View view, Menu menu) {
        if (menu != null) {
            if (menu.getClass() == MenuBuilder.class) {
                try {
                    Method m = menu.getClass().getDeclaredMethod("setOptionalIconsVisible", Boolean.TYPE);
                    m.setAccessible(true);
                    m.invoke(menu, true);
                } catch (Exception e) {
                }
            }
        }
        return super.onPrepareOptionsPanel(view, menu);
    }

    private final Toolbar.OnMenuItemClickListener listener = new Toolbar.OnMenuItemClickListener() {
        @Override
        public boolean onMenuItemClick(MenuItem item) {
            switch (item.getItemId()) {
                case R.id.addFriend:
                    Toast.makeText(MainActivity.this, "addFriend", Toast.LENGTH_SHORT).show();
                    break;
                case R.id.scan:
                    Toast.makeText(MainActivity.this, "scan", Toast.LENGTH_SHORT).show();
                    break;
                case R.id.newChat:
                    Toast.makeText(MainActivity.this, "newChat", Toast.LENGTH_SHORT).show();
                    //弹出自定义popWindow
                    //popUpMyOverflow();
                    break;
                case R.id.money:
                    Toast.makeText(MainActivity.this, "money", Toast.LENGTH_SHORT).show();
                    break;
            }
            return false;
        }
    };