无法从导航抽屉菜单项加载片段

Question

嗨，我是一名学生，正在尝试构建一个应用程序。 我想通过在导航抽屉上点击进入主要活动来加载片段。 我能够将导航抽屉附加到家庭活动中。 但是使用以下代码，我无法在活动中加载片段。 “ loadDashboard”功能工作正常，但“ onNavigationItemSelected”方法无效。 请帮助...代码在下面...

public class HomeActivity extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_home);
    loadDashboad();

    NavigationView nv = findViewById(R.id.navigation_view);
    nv.setNavigationItemSelectedListener(new NavigationView.OnNavigationItemSelectedListener() {
        @Override
        public boolean onNavigationItemSelected(@NonNull MenuItem item) {
            switch (item.getItemId()) {
                case R.id.menuitemdashboard:
                    getSupportFragmentManager().beginTransaction().replace(R.id.viewContainer, new dashboard()).commit();
                    break;
                case R.id.menuitemlogout:
                    break;
                case R.id.menuitemprofile:
                    break;
                case R.id.menuitemreports:
                    break;
                case R.id.menuitemvisits:
                    getSupportFragmentManager().beginTransaction().replace(R.id.viewContainer, new visits()).commit();
                    break;
            }
            return true;
        }
    });

}

private void loadDashboad() {
    FragmentManager fm = getSupportFragmentManager();
    FragmentTransaction ft = fm.beginTransaction();
    dashboard dash = new dashboard();
    ft.add(R.id.viewContainer, dash);
    ft.commit();
}

}

Answer 1

您的代码很好，您所缺少的是为导航菜单项提供功能。 将以下行替换为要添加的片段

FragmentManager fm = getSupportFragmentManager();
switch (item.getItemId()) {
    case R.id.menuitemdashboard:
        fm.beginTransaction().replace(R.id.viewContainer, new dashboard()).commit();
        break;
    case R.id.menuitemlogout:
        //TODO replace logout with fragment
        fm.beginTransaction().replace(R.id.viewContainer, //*log out*/).commit();
        break;
    case R.id.menuitemprofile:
        //TODO replace profile with fragment
        fm.beginTransaction().replace(R.id.viewContainer, //*profile*/).commit();
        break;
    case R.id.menuitemreports:
        //TODO replace reports with fragment
        fm.beginTransaction().replace(R.id.viewContainer, //*reports*/).commit();
        break;
    case R.id.menuitemvisits:
        fmbeginTransaction().replace(R.id.viewContainer, new visits()).commit();
        break;
}