android - ExpandableListView 重复子节点

Question

我已经实现了一个 ExpandableListAdapter，显然它运行良好。除了当 Activity 恢复时，子节点会重复。我不知道如何解决这个问题，我在网上搜索过这个，但没有找到任何有用的信息。

我已经通过添加一些 != null 检查来缓解这个问题。从而避免在不需要时插入和创建新数据。但这并没有解决问题。

这是 CustomAdapter

public class ContatoAdapter extends BaseExpandableListAdapter {

private final Activity context;
private final Map<String, List<Contato>> contatosCollection;
private final List<String> area;

public ContatoAdapter(Activity context, List<String> area, Map<String, List<Contato>> contatosCollection) {
    this.context = context;
    this.contatosCollection = contatosCollection;
    this.area = area;
}

@Override
public int getGroupCount() {
    return area.size() ;
}

@Override
public int getChildrenCount(int groupPosition) {
    return this.contatosCollection.get(area.get(groupPosition)).size();
}


@Override
public Object getGroup(int groupPosition) {
    return this.area.get(groupPosition);
}

@Override
public Object getChild(int groupPosition, int childPosition) {
    return this.contatosCollection.get(this.area.get(groupPosition)).get(childPosition);
}

@Override
public long getGroupId(int groupPosition) {
    return this.area.get(groupPosition).hashCode();
}

@Override
public long getChildId(int groupPosition, int childPosition) {
    return this.contatosCollection.get(this.area.get(groupPosition)).get(childPosition).hashCode();
}

@Override
public boolean hasStableIds() {
    return false;
}

@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
    String s = (String) getGroup(groupPosition);
    final LayoutInflater gInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    if (convertView == null){
        convertView = gInflater.inflate(R.layout.group_item, parent, false);
    }

    final TextView item = (TextView) convertView.findViewById(R.id.list_header);

    item.setText(s);
    item.setTypeface(null, Typeface.BOLD);

    return convertView;
}

@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
    final Contato contato = (Contato) getChild(groupPosition, childPosition);
    final LayoutInflater cInflater = this.context.getLayoutInflater();

    if (convertView == null){
        convertView = cInflater.inflate(R.layout.list_item, parent, false);
    }

    TextView item = (TextView) convertView.findViewById(R.id.list_item_nome);
    ImageView ver = (ImageView) convertView.findViewById(R.id.list_item_ver);

    ver.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            Intent intent = new Intent(context.getApplicationContext(), DetalheActivity.class);
            intent.putExtra("contato", contato);
            context.startActivity(intent);
        }
    });

    item.setText(contato.getNome());

    return convertView;
}

@Override
public boolean isChildSelectable(int groupPosition, int childPosition) {
    return true;
}
}

这是具有适配器的 listView 的 Activity :

public class MedicosActivity extends AppCompatActivity {
private ExpandableListView listView;
private ArrayList<Contato> contatos;
private ArrayList<String> areas;
private HashMap<String, List<Contato>> contatosCollection;
private ContatoAdapter adapter;

String jsonString = "";

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

    setTitle("Médicos | Etc");

    init();

    if (listView == null)
        listView = (ExpandableListView) findViewById(android.R.id.list);
    adapter = new ContatoAdapter(this,areas,contatosCollection);
    listView.setAdapter(adapter);

    listView.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {
        @Override
        public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) {
            Contato selected = (Contato) adapter.getChild(groupPosition,childPosition);
            Toast.makeText(MedicosActivity.this, selected.getNome() , Toast.LENGTH_SHORT).show();

            return true;
        }
    });
}

private void init() {
    if (jsonString.isEmpty())
        jsonString =  JsonUtil.loadJSON(MedicosActivity.this, "data.json");
    if (contatosCollection == null)
        contatos = JsonUtil.parseJSON(jsonString);
    if (areas == null){
        areas = new ArrayList<>();
        createGroupList();
    }
    if (contatosCollection == null){
        contatosCollection = new HashMap<>();
        createCollection();
    }
}

private void createGroupList() {
    for(Contato c : contatos){
        if (!areas.contains(c.getArea())){
            areas.add(c.getArea());
        }
    }
}

private void createCollection() {
    for (Contato c : contatos){
        List<Contato> ctg = contatosCollection.get(c.getArea());
        if (ctg == null){
            ctg = new ArrayList<>();
            contatosCollection.put(c.getArea(), ctg);
        }
        ctg.add(c);
    }
}
}

添加导致错误的 JSON 解析器类:

private static ArrayList<Contato> contatoList = new ArrayList<>();
public static ArrayList<Contato> parseJSON(String jsonString){
    try {
        JSONObject jsonObject = new JSONObject(jsonString);
        JSONArray jsonArray = jsonObject.optJSONArray("medicos");

        for (int i = 0; i < jsonArray.length(); i++){
            JSONObject medicoObj = jsonArray.getJSONObject(i);
             JSONObject end = medicoObj.getJSONObject("endereco");
                JSONArray coord = end.getJSONArray("coord");
                LatLng latLng = new LatLng(coord.getDouble(0), coord.getDouble(1));
                JSONArray telefones = medicoObj.getJSONArray("telefone");
                String[] tels = new String[telefones.length()];
                for (int j = 0; i < telefones.length(); i++) {
                    tels[i] = telefones.get(i).toString();
                }
                Contato c = new Contato(
                        medicoObj.getString("area")
                        , medicoObj.getString("nome")
                        , end.getString("rua")
                        , Integer.parseInt(end.getString("numero"))
                        , end.getString("complemento")
                        , tels
                        , latLng
                );
                contatoList.add(c);
        }

        return contatoList;
    } catch (JSONException e) {
        e.printStackTrace();
    }
    return null;
}

Answer 1

感谢 Liquid Penguin 评论，我能够检测到问题。由于我正在研究 Adapter 类的问题，所以我没有注意到来自 JSON 解析器 类的重复数据。

从 JSON 获取数据到数组时，它没有检查重复数据。带有所需验证的固定解析器 code 如下:

 private static ArrayList<Contato> contatoList = new ArrayList<>();
public static ArrayList<Contato> parseJSON(String jsonString){
    try {
        JSONObject jsonObject = new JSONObject(jsonString);

        JSONArray jsonArray = jsonObject.optJSONArray("medicos");

            for (int i = 0; i < jsonArray.length(); i++) {
                JSONObject medicoObj = jsonArray.getJSONObject(i);
                if (medicoObj.length() != contatoList.size()) {
                    JSONObject end = medicoObj.getJSONObject("endereco");
                    JSONArray coord = end.getJSONArray("coord");
                    LatLng latLng = new LatLng(coord.getDouble(0), coord.getDouble(1));
                    JSONArray telefones = medicoObj.getJSONArray("telefone");
                    String[] tels = new String[telefones.length()];
                    for (int j = 0; i < telefones.length(); i++) {
                        tels[i] = telefones.get(i).toString();
                    }
                    Contato c = new Contato(
                            medicoObj.getString("area")
                            , medicoObj.getString("nome")
                            , end.getString("rua")
                            , Integer.parseInt(end.getString("numero"))
                            , end.getString("complemento")
                            , tels
                            , latLng
                    );
                    if (!contatoList.contains(c))
                        contatoList.add(c);
                }
            }

        return contatoList;
    } catch (JSONException e) {
        e.printStackTrace();
    }
    return null;
}