在 android 中得到响应后，如何在 ListView 中绑定数据？

Question

我正在创建一个具有动态 ListView 的应用程序，它应该从服务器获取数据并在获得响应后绑定它们，点击 Button。我已经完成了接收响应。但是不知道如何将数据绑定到 ListView。我还创建了一个用于绑定的适配器。但不知道如何通过适配器绑定数据。谁能帮我？我在下面给出了我的代码以供参考..

主要Activity.java（来自onCreate）：

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

    list = (ListView) findViewById(R.id.take_payment_list);
    adapter = new CustomListAdapter(this, notifications);
    list.setAdapter(adapter);

    refresh_btn = (Button) findViewById(R.id.refresh_btn);

    refresh_btn.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {

            HttpHandler httpHandler1 = new HttpHandler();
            String res = null;


            try {

                Log.d("edwLog", TAG + " get_payment_notifications " + HttpHandler.API_URL + "get_payment_notifications/" + AuthToken + "/");
                res = httpHandler1.makeServiceCall(HttpHandler.API_URL + "get_payment_notifications/" + AuthToken + "/", HttpHandler.GET);
                Log.d("edwLog", TAG + " response > " + res);
                if (res != null) {
                    JSONObject jsonObject = new JSONObject(res);
                    String responseType = jsonObject.getString("type");
                    if (responseType.equals("success")) {
                        if (jsonObject.has("response")) {

                            JSONArray jsonArray = jsonObject.getJSONArray("response");
                            for (int i = 0; i < jsonArray.length(); i++) {
                                notificationsresponse.add(jsonArray.getJSONObject(i));
                            }


                        }
                    }
                }



            } catch (Exception e) {
                e.printStackTrace();
                Log.d("edwLog", TAG + " IOException > " + e.toString());
            }

            adapter.notifyDataSetChanged();
        }
    });

适配器Class:

public class CustomListAdapter extends BaseAdapter {

private final Activity activity;
private LayoutInflater inflater;
private List<Users> notifications;

ImageLoader imageLoader = AppController.getInstance().getImageLoader();

public CustomListAdapter(Activity activity, List<Users> notifications) {
    this.activity = activity;
    this.notifications = notifications;
}

@Override
public int getCount() {
    return notifications.size();
}

@Override
public Object getItem(int location) {
    return notifications.get(location);
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {

    if (inflater == null)
        inflater = (LayoutInflater) activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    if (convertView == null)
        convertView = inflater.inflate(R.layout.custom_rows, null);

    if (imageLoader == null)
        imageLoader = AppController.getInstance().getImageLoader();

    NetworkImageView thumbNail = (NetworkImageView) convertView.findViewById(R.id.thumbnail);


    TextView name = (TextView) convertView.findViewById(R.id.txt_customer_name4);
    TextView time = (TextView) convertView.findViewById(R.id.txt_notification_time4);

    // getting notifications data for the row
    Users m = notifications.get(position);

    // thumbnail image
    thumbNail.setImageUrl(m.getThumbnailurl(), imageLoader);

    // name
    name.setText(m.getName());

    // notification time
    /*time.setText(String.valueOf(m.getTime()));*/
    CharSequence timeAgo = DateUtils.getRelativeTimeSpanString(
            Long.parseLong(m.getTime()), System.currentTimeMillis(), DateUtils.SECOND_IN_MILLIS);
            time.setText(timeAgo);


    return convertView;
}



}

Answer 1

做简单的步骤：

在您的适配器中覆盖方法：

public void notifyDataSetChanged(List<Users> notifications){
   this.notifications = notifications;
   super.notifyDataSetChanged();
}

现在，而不是调用：

adapter.notifyDataSetChanged();

称其为：

adapter.notifyDataSetChanged(notificationsresponse);

另外，您从服务器获取数据的方法不正确。当您尝试在主 UI 线程上获取数据时，这会降低用户体验。您应该仅在异步线程中调用 server/database 调用并在 UI 线程上更新该响应。

Answer 2

首先，永远不要在主线程上调用 Web 服务，在 AsyncTask 中调用它们。 AsyncTask 将是您 Activity/Fragment class 的内部 class。

private class WebServiceCaller extends AsyncTask<String, Void, JSONObject> {

    @Override
    protected JSONObject doInBackground(String... params) {
        //Call your web service here
        }
        return response; //the json response you get
    }

    @Override
    protected void onPostExecute(JSONObject result) {
        //here bind the data using your adapter to the listview
        //Parse the JSONObject you get as the response and add them to the list of Your User
        //now call the adapter
        adapter= new CustomListAdapter(MainActiviy.this,List);
        listView.setAdapter(adapter);
    }

    @Override
    protected void onPreExecute() {}

    @Override
    protected void onProgressUpdate(Void... values) {}
}

Answer 3

如果你想再次使用获取的数据然后首先将它存储在 Sqlite 数据库，如果不是然后使用 ArrayAdapter将数据绑定到 listView。

参考thislink.

Answer 4

首先创建一个适配器，您已经完成了：

list = (ListView) findViewById(R.id.take_payment_list);
adapter = new CustomListAdapter(this, notifications);
list.setAdapter(adapter);

但是第2行列表项丢失，其余一切正常：

adapter = new CustomListAdapter(this,<<listItem>>, notifications);

收到回复后现在

将您的项目添加到通知数组，然后更改适配器以获得新的通知数组：

notifications.add("data");
adapter = new CustomListAdapter(this,<<listItem>>, notifications);

Answer 5

在你们的帮助下成功找到了。收到响应后，只需添加这 3 行代码。对于我的应用程序，它是这样的：

adapter = new CustomListAdapter(TakePayment.this, R.layout.custom_rows, (ArrayList<JSONObject>) notificationsresponse);
list.setAdapter(adapter);
adapter.notifyDataSetChanged();

在 android 中得到响应后，如何在 ListView 中绑定数据？

How to bind data in ListView after getting responses in android?

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