java - Android抽屉导航点击事件问题

Question

我正在创建一个包含抽屉导航 Activity 的应用程序。我正在主屏幕中加载不同的 fragment 。现在，当我必须调用 Fragment 时，它工作得很好，但是当我想调用某种服务(例如调用、图像选择器)时，我添加了 setNavigationItemSelectedListener ，它工作得很好，但所有其他 fragment 现在都没有加载。

  protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        getSupportActionBar().setDisplayHomeAsUpEnabled(true);

        drawer = findViewById(R.id.drawer_layout);
        NavigationView navigationView = findViewById(R.id.nav_view);


        // Passing each menu ID as a set of Ids because each
        // menu should be considered as top level destinations.
        mAppBarConfiguration = new AppBarConfiguration.Builder(
                R.id.nav_home, R.id.nav_gallery, R.id.nav_slideshow, R.id.nav_franchise,
                R.id.nav_tieUP, R.id.nav_giftVoucher, R.id.nav_faq, R.id.nav_privacy_policy,
                R.id.nav_tools, R.id.nav_send)
                .setDrawerLayout(drawer)
                .build();
        NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
        NavigationUI.setupActionBarWithNavController(this, navController, mAppBarConfiguration);
        NavigationUI.setupWithNavController(navigationView, navController);

        navigationView.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
            @Override
            public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {

                int id = menuItem.getItemId();
                if (id == R.id.callUs) {
                    Intent intent = new Intent(Intent.ACTION_CALL);

                    intent.setData(Uri.parse("tel:" + "XXXxxxXXX"));

                    if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.CALL_PHONE) != PackageManager.PERMISSION_GRANTED) {
                        ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.CALL_PHONE},REQUEST_PHONE_CALL);
                    }
                    else
                    {
                        startActivity(intent);
                    }
                }

                drawer.closeDrawer(GravityCompat.START);
                return true;
            }
        });

    }

Answer 1

当您调用 NavigationUI.setupWithNavController(navigationView, navController) 时，您是在说您希望 NavController 处理来自 NavigationView 的点击事件，导航到相关屏幕根据the NavigationUI documentation 。这必然会在内部调用 setNavigationItemSelectedListener()。

通过随后调用 setNavigationItemSelectedListener，您可以删除原始监听器，这就是您的其他项目不再执行任何操作的原因。您可以通过调用 NavigationUI.onNavDestinationSelected() 来触发默认行为

@Override
public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {

    int id = menuItem.getItemId();
    if (id == R.id.callUs) {
        Intent intent = new Intent(Intent.ACTION_CALL);

        intent.setData(Uri.parse("tel:" + "XXXxxxXXX"));

        if (ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.CALL_PHONE) != PackageManager.PERMISSION_GRANTED) {
            ActivityCompat.requestPermissions(MainActivity.this, new String[]{Manifest.permission.CALL_PHONE},REQUEST_PHONE_CALL);
        }
        else
        {
            startActivity(intent);
        }
   }
   else
   {
       // Make your navController object final above
       // or call Navigation.findNavController() again here
       NavigationUI.onNavDestinationSelected(menuItem, navController);
   }
   drawer.closeDrawer(GravityCompat.START);
   return true;

}