使用 bundle 在 tablayout 之间传递数据

Question

我正在使用 Bundle 从我的第一个 TabFragment 传递数据，但它提示 NullPointerException。当 getArguments() in list_fragments2 in second tab

时发生错误

MainActivity 片段

list_fragment2 fragment = new list_fragment2();
Bundle b = new Bundle();
b.putString("test","text");
fragment.setArguments(b);
Toast.makeText(this, "" + b, Toast.LENGTH_SHORT).show();

SecondActivity 片段

 public class list_fragment2 extends Fragment {

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        View h = inflater.inflate(R.layout.tab2, container, false);
        TextView textView = (TextView) h.findViewById(R.id.textView);

        Bundle bundle=getArguments();

        //your string
        if(bundle != null) {
            String test = bundle.getString("test");
            textView.setText(test);
        }
            return h;

    }
}

Answer 1

你真的加载了你的第二个片段吗？

FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();

list_fragment2 fragment = new list_fragment2();
Bundle b = new Bundle();
b.putString("test","text");
fragment.setArguments(b);
fragmentTransaction.replace(placeholder, fragment);
fragmentTransaction.commit();

Answer 2

我认为您可以在 list_fragment2 中创建 list_fragment2 代码实例。也许您的代码重新创建了 list_fragment2 多次。

public static list_fragment2 createInstance() {
        list_fragment2 fragment = new list_fragment2();
        Bundle bundle = new Bundle();
        bundle .putString("test","text");
        fragment.setArguments(bundle);
        return fragment;
    }