Question

我目前在片段中实现listview时遇到问题。我使用Hashmap然后转换为arrayList，如下所示：

     public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    final View myView = inflater.inflate(
            R.layout.fragment_portfolio, container, false);
    ListView listview = (ListView) myView.findViewById(R.id.listview);

    List<HashMap<String, Integer>> fillMaps = new ArrayList<>();
    HashMap<String, Integer> portfoliodata = new HashMap<>();
    portfoliodata.put("Test", 23);
    fillMaps.add(portfoliodata);
    SimpleAdapter adapter = new SimpleAdapter(getActivity().getApplicationContext(), fillMaps, R.layout.my_adapter_item, new String[] { "AAA","BBB" },
            new int[] { android.R.id.text1, android.R.id.text2 });
    listview.setAdapter(adapter);
    return myView;
}

然而，结果总是一个完全空白的片段。知道为什么会这样做以及如何解决这个问题？

提前谢谢

Answer 1

方法onCreateView（）中不存在

getActivity（），因为您还没有Activity的上下文。

您可以探测将代码移动到onResume（）方法。

*请记住，您必须使用数据连接每一列，如下所示：

ListView listview;

public View onCreateView(LayoutInflater inflater, ViewGroup container,
                     Bundle savedInstanceState) {
    View myView = inflater.inflate(
        R.layout.fragment_portfolio, container, false);

    listview = (ListView) myView.findViewById(R.id.listview);

    return myView;
} 

@Override
public void onResume() {
    // create the grid item mapping
    String[] from = new String[] {"AAA","BBB"};
    int[] to = new int[] {android.R.id.text1, android.R.id.text2};

    List<HashMap<String, String>> fillMaps = new ArrayList<>();
    HashMap<String, String> portfoliodata = new HashMap<>();
    portfoliodata.put("AAA", "Text SampleA");
    portfoliodata.put("BBB", "Text SampleB");
    fillMaps.add(portfoliodata);

    SimpleAdapter adapter = new SimpleAdapter(getActivity(), fillMaps, 
        R.layout.my_adapter_item, from, to);
    listview.setAdapter(adapter);
}

祝你好运！

Android - Listview保持空白

1 个答案: