在选定的底部导航视图项上重新创建片段

问题描述

以下是我选择的底部导航视图项的代码

Following is my code for bottom navigation view item selected

bottomNavigationView.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
    Fragment fragment = null;
    switch (item.getItemId()) {
        case R.id.action_one:
            // Switch to page one
            fragment = FragmentA.newInstance();
            break;
        case R.id.action_two:
            // Switch to page two
            fragment = FragmentB.newInstance();
            break;
        case R.id.action_three:
            // Switch to page three
            fragment = FragmentC.newInstance();
            break;
    }
    getSupportFragmentManager().beginTransaction().replace(R.id.container,fragment,"TAG").commit();
    return true;
}
});

现在我的问题是每次重新创建片段时都不希望每次我也尝试添加addToBackStack(null)时都希望重新创建片段，但是这种情况在按下后退按钮时会不断从堆栈中弹出片段，而我不这样做不想.

Now my problem is every time fragment is re-created and don't want fragment to be recreated every time I also tried adding addToBackStack(null) but it this case on back button press keeps popping fragments from stack which I don't want.

有什么方法可以在不重新创建片段的情况下在底部导航栏上显示片段

Is there any way to display fragments on bottom navigation bar selected without re-creating fragment

推荐答案

有了支持库v26，您可以做到这一点

With support library v26 you can do this

FragmentTransaction fragmentTransaction = mFragmentManager.beginTransaction();

Fragment curFrag = mFragmentManager.getPrimaryNavigationFragment();
if (curFrag != null) {
    fragmentTransaction.detach(curFrag);
}

Fragment fragment = mFragmentManager.findFragmentByTag(tag);
if (fragment == null) {
    fragment = new YourFragment();
    fragmentTransaction.add(container.getId(), fragment, tag);
} else {
    fragmentTransaction.attach(fragment);
}

fragmentTransaction.setPrimaryNavigationFragment(fragment);
fragmentTransaction.setReorderingAllowed(true);
fragmentTransaction.commitNowAllowingStateLoss();

这篇关于在选定的底部导航视图项上重新创建片段的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！