使用 onOptionsItemSelected 显示/隐藏 Searchview

Question

我想让我的 Searchview 仅在我从抽屉中打开产品选项时可见，为此我正在尝试使用 onOptionsItemSelected 方法来监听正在使用的选项。 问题是我每次尝试从 onOptionsItemSelected 获取 SearchView id 时总是得到 NullPointerException。

我知道如何在 onCreateOptionsMenu 中隐藏 SearchView 使用：

menu.findItem(R.id.action_search).setVisible(false);

这是我的 onCreateOptionsMenu 的源代码：

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);

    View lay = findViewById(R.id.nav_header);
    //id in this line is found
    menu.findItem(R.id.action_search).setVisible(false);

    sharedpreferences = getSharedPreferences(Login.my_shared_preferences, Context.MODE_PRIVATE);
    session = sharedpreferences.getBoolean(session_status, false);
    id = sharedpreferences.getString(TAG_ID, null);
    username = sharedpreferences.getString(TAG_USERNAME, null);
    name = sharedpreferences.getString(TAG_NAME, null);

    txt_id = lay.findViewById(R.id.txt_id_admin);
    txt_username = lay.findViewById(R.id.txt_textView);
    txt_name = lay.findViewById(R.id.txt_name_admin);
    imb = lay.findViewById(R.id.btn_exit);

    txt_id.setText("ID : " + id);
    txt_name.setText("Nama : " + name);
    txt_username.setText("Status : " + username);

    imb.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            SharedPreferences.Editor editor = sharedpreferences.edit();
            editor.clear();
            editor.commit();

            intent = new Intent(getApplicationContext(), Login.class);
            finish();
            startActivity(intent);
        }
    });
    return true;

但我不能在 onOptionsItemSelected 方法中做同样的事情，因为它使用的参数是 MenuItem 而不是 Menu。

这是我对 onOptionsItemSelected 方法的最新尝试：

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    NavigationView navigationView = findViewById(R.id.nav_view);
    Menu menu = navigationView.getMenu();
    //id in this line is null
    MenuItem item_search = menu.findItem(R.id.action_search);
    Log.d(TAG, "Response : " + item_search);
    SearchView searchView = (SearchView) item_search.getActionView();

    if (item.getItemId() == R.id.nav_produk) {
        searchView.setVisibility(View.VISIBLE);
        return true;
    } else {
        Log.d(TAG, "Response : " + searchView);
        searchView.setVisibility(View.INVISIBLE);
        return super.onOptionsItemSelected(item);
    }
}

这是我的 res/menu/main.xml 文件：

<?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/action_settings"
    android:visible="false"
    android:orderInCategory="100"
    android:title="@string/action_settings"
    app:showAsAction="never"/>
<item
    android:id="@+id/action_search"
    android:visible="true"
    android:orderInCategory="100"
    android:icon="@android:drawable/ic_menu_search"
    android:title="@string/search"
    app:actionViewClass="android.widget.SearchView"
    app:showAsAction="ifRoom|collapseActionView"/>

Answer 1

我已经找到答案了！显然我根本不需要 onOptionsItemSelected。

我在我的 DrawerLayout 上使用 NavController，所以制作监听器的更简单方法是在 onCreateOptionsMenu

中使用 onDestinationChanged 方法

这是结果：

    @Override
    public boolean onCreateOptionsMenu(final Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);

    View lay = findViewById(R.id.nav_header);
    menu.findItem(R.id.action_search).setVisible(false);

    sharedpreferences = getSharedPreferences(Login.my_shared_preferences, Context.MODE_PRIVATE);
    session = sharedpreferences.getBoolean(session_status, false);
    id = sharedpreferences.getString(TAG_ID, null);
    username = sharedpreferences.getString(TAG_USERNAME, null);
    name = sharedpreferences.getString(TAG_NAME, null);

    txt_id = lay.findViewById(R.id.txt_id_admin);
    txt_username = lay.findViewById(R.id.txt_textView);
    txt_name = lay.findViewById(R.id.txt_name_admin);
    imb = lay.findViewById(R.id.btn_exit);

    txt_id.setText("ID : " + id);
    txt_name.setText("Nama : " + name);
    txt_username.setText("Status : " + username);

    imb.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            SharedPreferences.Editor editor = sharedpreferences.edit();
            editor.clear();
            editor.commit();

            intent = new Intent(getApplicationContext(), Login.class);
            finish();
            startActivity(intent);
        }
    });
    
    //Only show SearchView when produk is open
    NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
    navController.addOnDestinationChangedListener(new NavController.OnDestinationChangedListener() {
        @Override
        public void onDestinationChanged(@NonNull NavController controller, @NonNull NavDestination destination, @Nullable Bundle arguments) {
            if (destination.getId() == R.id.nav_produk) {
                menu.findItem(R.id.action_search).setVisible(true);
            } else {
                menu.findItem(R.id.action_search).setVisible(false);
            }
        }
    });
    
    return true;
}