Question

我目前正在YouTube上观看一些有关如何向我的超级简单应用添加底部导航的教程。我到达了片段之间过渡的最后一部分，他在Kotlin中写了这篇文章，而我却没有对此进行研究。我该如何用Java编写？我想这有点相似，但是我对Java也很陌生，所以如果这听起来真是愚蠢，我感到很抱歉。

[ProjectName][12943:1296641] Failed to set (titleText) user defined inspected property on ([ProjectName].RoundedCornerButton): 
[<[ProjectName].RoundedCornerButton 0x7f8a13d0bd90> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key titleText.

Answer 1

Java代码

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

    final Fragment fragment_weekly = new FirstFragment();
    final Fragment fragment_biweekly = new SecondFragment();
    final Fragment fragment_monthly = new ThirdFragment();

    setCurrentFragment(fragment_weekly);

    bottomNavigationView.setOnNavigationItemSelectedListener(
            new BottomNavigationView.OnNavigationItemSelectedListener() {
                @Override
                public boolean onNavigationItemSelected(@NonNull MenuItem menuItem) {
                    switch (menuItem.getItemId()) {
                        case R.id.weekly: {
                            setCurrentFragment(fragment_weekly);
                            break;
                        }
                        case R.id.biweekly: {
                            setCurrentFragment(fragment_biweekly);
                            break;
                        }
                        case R.id.monthly: {
                            setCurrentFragment(fragment_monthly);
                            break;
                        }
                    }
                    return true;
                }
            });
}

private void setCurrentFragment(Fragment fragment) {
    getSupportFragmentManager()
            .beginTransaction()
            .replace(R.id.flFragment, fragment)
            .commit();
}

Kotlin至Java，底部导航栏

1 个答案: