android - 如何使用 getter 和 setter 方法在可扩展 ListView 上获取组和子项

Question

大家好，我想在 ExpandableListView 的 setOnGroupClickListener 和 setOnChildClickListener 上获取项目，但没有获取它的项目。

这是我的代码:

组.java

public class Group {

private String Name;
private ArrayList<Child> Items;

public String getName() {
    return Name;
}

public void setName(String name) {
    Name = name;
}

public ArrayList<Child> getItems() {
    return Items;
}

public void setItems(ArrayList<Child> items) {
    Items = items;
}
}

子类.java

public class Child {
private String Name;

public String getName() {
    return Name;
}

public void setName(String name) {
    Name = name;
}
}

扩展列表适配器.java

public class ExpandListAdapter extends BaseExpandableListAdapter {

private Context context;
private ArrayList<Group> groups;

public ExpandListAdapter(Context context, ArrayList<Group> groups) {
    this.context = context;
    this.groups = groups;
}

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

@Override
public int getChildrenCount(int groupPosition) {
    ArrayList<Child> chList = groups.get(groupPosition).getItems();
    return chList.size();
}

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

@Override
public Object getChild(int groupPosition, int childPosition) {
    ArrayList<Child> chList = groups.get(groupPosition).getItems();
    return chList.get(childPosition);
}

@Override
public long getGroupId(int groupPosition) {
    return groupPosition;
}

@Override
public long getChildId(int groupPosition, int childPosition) {
    return childPosition;
}

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

@Override
public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) {
    Group group = (Group) getGroup(groupPosition);
    if (convertView == null) {
        LayoutInflater inf = (LayoutInflater) context.getSystemService(context.LAYOUT_INFLATER_SERVICE);
        convertView = inf.inflate(R.layout.group_item, null);
    }
    TextView tv = (TextView) convertView.findViewById(R.id.group_name);
    tv.setText(group.getName());
    return convertView;
}

@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
    Child child = (Child) getChild(groupPosition, childPosition);
    if (convertView == null) {
        LayoutInflater infalInflater = (LayoutInflater) context
                .getSystemService(context.LAYOUT_INFLATER_SERVICE);
        convertView = infalInflater.inflate(R.layout.child_item, null);
    }

    TextView tv = (TextView) convertView.findViewById(R.id.country_name);

    tv.setText(child.getName().toString());

    return convertView;
}

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

主 Activity .java

public class MainActivity extends AppCompatActivity {

String url = "http://ec2-52-40-135-171.us-west-2.compute.amazonaws.com/shop-cart/backend/web/api/category";

private ExpandListAdapter ExpAdapter;
private ExpandableListView ExpandList;

ArrayList<Group> list;
ArrayList<Child> ch_list;
Group gru;


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

    ExpandList = (ExpandableListView) findViewById(R.id.exp_list);

    list = new ArrayList<Group>();


    makejsonobjreq();


    ExpandList.setOnGroupClickListener(new ExpandableListView.OnGroupClickListener() {
        @Override
        public boolean onGroupClick(ExpandableListView expandableListView, View view, int i, long l) {

            Toast.makeText(MainActivity.this, list.get(i) + "", Toast.LENGTH_SHORT).show();

            return false;
        }
    });

    ExpandList.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {
        @Override
        public boolean onChildClick(ExpandableListView expandableListView, View view, int i, int i1, long l) {

            Toast.makeText(MainActivity.this, "" + ExpAdapter.getChild(i, i1), Toast.LENGTH_SHORT).show();

            return false;
        }
    });
}

private void makejsonobjreq() {

    JsonObjectRequest jsonObjectRequest = new JsonObjectRequest(url, null, new Response.Listener<JSONObject>() {
        @Override
        public void onResponse(JSONObject response) {
            Log.e("RES", String.valueOf(response));


            try {
                JSONObject jo = response.getJSONObject("data");
                Log.e("data RES", jo.toString());

                Log.e("dataLENGTH", String.valueOf(jo.length()));

                //CHNGE NEEDED ==> REPLACE 2 WITH jo.length();
                for (int i = 0; i < 2; i++) {

                    gru = new Group();
                    gru.setName(jo.getJSONObject(String.valueOf(i + 1)).getJSONArray("parent").getJSONObject(0).getString("name"));

                    Log.e("gru", gru.getName());
                    ch_list = new ArrayList<Child>();

                    JSONArray ja = jo.getJSONObject(String.valueOf(i + 1)).getJSONArray("child");
                    Log.e("child ARRAY", String.valueOf(ja));
                    Log.e("child LENGTH", String.valueOf(ja.length()));

                    for (int j = 0; j < ja.length(); j++) {

                        Child ch = new Child();
                        ch.setName(ja.getJSONObject(j).getString("name"));
                        ch_list.add(ch);

                        Log.e("CHILD NAME", "VAL OF J  " + j + "   " + ja.getJSONObject(j).getString("name"));
                    }
                    gru.setItems(ch_list);
                    list.add(gru);
                }

                ExpAdapter = new ExpandListAdapter(MainActivity.this, list);
                ExpandList.setAdapter(ExpAdapter);

            } catch (JSONException e) {
                e.printStackTrace();
            }

        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {

        }
    });
    RequestQueue requestQueue = Volley.newRequestQueue(this);
    requestQueue.add(jsonObjectRequest);
}
}

Answer 1

将您的项目作为标签放入 getChildView 或 getGroupView 中，如下所示:

@Override
public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) {
    Child child = (Child) getChild(groupPosition, childPosition);
    // keep your code
    // set item as a tag
    convertView.setTag(child);
    return convertView;
}

然后你可以在回调中获取项目

ExpandList.setOnChildClickListener(new ExpandableListView.OnChildClickListener() {
    @Override
    public boolean onChildClick(ExpandableListView expandableListView, View view, int i, int i1, long l) {
        // get tag from view, it will be better if your check the object type.
        Child child = (Child)view.getTag();
        return false;
    }
});