传递HashMap, bundle返回null

Question

我试图通过bundle将HashMap传递给另一个fragment。然而，我的bundle返回null。

我用这个

创建bundle

protected void onPostExecute(String string) {
        // dismiss the dialog
        pDialog.dismiss();
        int a = 0;
        Bundle bundle = new Bundle();
        Fragment fragment = new Assessment_Fragment();
        for (int i = 0; i < infoList.size(); i++) {
            // get HashMap
            HashMap<String, String> map = infoList.get(i);
            // autoincremented key for retreiving as many HashMaps as needed
            bundle.putSerializable("" + a, map); 
            // so i will know how many hashmaps exist
            bundle.putInt("key", a);
            // increment key
            a++;
        }
        fragment.setArguments(bundle);
    };

这就是我接收bundle

的方式

public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        view = inflater.inflate(R.layout.fragment_assessment, container, false);
        // check for values
        if (getArguments() != null) {
            // application never gets here !
            int a = getArguments().getInt("key");
            for (int i = 0; i < a; i++) {
                @SuppressWarnings("unchecked")
                HashMap<String, String> map = (HashMap<String, String>) getArguments()
                        .getSerializable("" + i);
                if (map.get(TAG_FIELD).equals(r)) {...

应用程序没有崩溃，没有错误。这个fragment永远不会膨胀，因为bundle永远不会是!= null。我做错了什么?

Answer 1

在onPostExecute()中，您必须通过FragmentTransaction替换或添加片段:

 Fragment newFragment = CountingFragment.newInstance(mStackLevel);
 FragmentTransaction ft = getFragmentManager().beginTransaction();
 ft.add(R.id.simple_fragment, fragment).commit();

还可以避免迭代infoList来获取和放置每个HashMap到bundle中。你可以直接输入infoList