Question

我有一个列表视图，并希望根据每个列表视图项的数据发送请求。随后，我需要更新我发送的特定请求的textview。

这是我的arrayAdapter，我在其中填充listview并发送http请求

 public class ListAdapter extends ArrayAdapter<lProperty> {

Context mContext;
List<lProperty> values = null;

 public ListAdapter(Context mContext,  List<lProperty> data) {

   super(mContext, R.layout.list_row, data);
   this.mContext = mContext;
   this.values = data;
   layoutInflater = LayoutInflater.from(mContext);
   asyn = new AsyncHelper();
} 
   static class ViewHolder {
    public ImageView image;
    public TextView type;
    public TextView info;
    public RelativeLayout rl;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
   holder = new ViewHolder();
   if (convertView == null) {
       holder = new ViewHolder();
       convertView = layoutInflater.inflate(R.layout.list_row,
               null);
       holder.rl = (RelativeLayout) convertView.findViewById(R.id.row_layout);
       holder.image = (ImageView) convertView.findViewById(R.id.images);
       holder.type = (TextView) convertView.findViewById(R.id.type);
       holder.info = (TextView) convertView.findViewById(R.id.info);


       convertView.setTag(holder);

   } else
       holder = (ViewHolder) convertView.getTag();
   Log.d(TAG, "List Size"+values.size());

   holder.type.setText(values.get(position).type);
   if(values.get(position).type.equals("Outsider")){
       holder.info.setText(values.get(position).outside);
   }
   if(values.get(position).type.equals("Student")){
       String url = "https:abc.com&code=" + values.get(position).code + "&type="+ values.get(position).type;
       new HttpAsyncTask().execute(url);
       holder.info.setText(marks);
   }
   if(values.get(position).type.equals("Employee")){
       String url = "https:abc.com&code=" + values.get(position).code + "&type="+ values.get(position).type;
       new HttpAsyncTask().execute(url);
       holder.info.setText(marks);
   }
   if(values.get(position).type.equals("Other")){
       String url = "https:abc.com&code=" + values.get(position).code + "&type="+ values.get(position).type;
       new HttpAsyncTask().execute(url);
       holder.info.setText(operator);
    }
   return convertView;

}

private class HttpAsyncTask extends AsyncTask<String, Void, String> {

    @Override
    protected void onPreExecute()
    {

    };
    @Override
    protected String doInBackground(String... urls) {
        Log.d(TAG," URL"+urls[0]);
        return GET(urls[0]);
    }
    // onPostExecute displays the results of the AsyncTask.
    @Override
    protected void onPostExecute(String result) {
        try {
            JSONArray reader = new JSONArray(result);
            if (!(reader.isNull(0))) {
                holder.info.setText(reader.getJSONObject(0).getString("marks"));
                Log.d(TAG, "Marks" + marks);

            } else {
                holder.info.setText("Not Found");
            }
        } catch (JSONException j){
            j.printStackTrace();
        }

    }
}

public static String GET(String url){
    InputStream inputStream = null;
    String result = "";
    try {
        String jsonreply;
        StringBuilder builder = new StringBuilder();
        HttpClient client = asyn.getNewHttpClient();
        HttpGet httpGet = new HttpGet(url);
        try {
            HttpResponse response = client.execute(httpGet);
            StatusLine statusLine = response.getStatusLine();
            int statusCode = statusLine.getStatusCode();
            if (statusCode == 200) {
                HttpEntity entity = response.getEntity();
                InputStream content = entity.getContent();
                BufferedReader reader = new BufferedReader(
                        new InputStreamReader(content));
                String line;
                while ((line = reader.readLine()) != null) {
                    builder.append(line);
                }
            } else {

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

        } catch (IOException e) {
            e.printStackTrace();
        }
        jsonreply = builder.toString();
        return jsonreply;



    } catch (Exception e) {
        Log.d("InputStream", e.getLocalizedMessage());
    }

    // 11. return result
    return result;
}

static String TAG= "ListAdapter";
private LayoutInflater layoutInflater;
static AsyncHelper asyn;
ViewHolder holder;
String marks = null;

} 我也可以发送请求并接收数据，但是我无法就请求发送和更新相同的textview，任何建议建立关系

Answer 1

尝试在更改文本值后添加notifyDataSetChanged()：

 if (!(reader.isNull(0))) {
                holder.info.setText(reader.getJSONObject(0).getString("marks"));
                notifyDataSetChanged(); //refresh your adapter
                Log.d(TAG, "Marks" + marks);

            }

在你的getView中，我觉得你最好这样做：

  if(values.get(position).type.equals("Outsider")){
       holder.info.setText(values.get(position).outside);
   }
   else if(values.get(position).type.equals("Student")){
       String url = "https:abc.com&code=" + values.get(position).code + "&type="+ values.get(position).type;
       new HttpAsyncTask().execute(url);
       holder.info.setText(marks);
   }
   else if(values.get(position).type.equals("Employee")){
       String url = "https:abc.com&code=" + values.get(position).code + "&type="+ values.get(position).type;
       new HttpAsyncTask().execute(url);
       holder.info.setText(marks);
   }
   else if(values.get(position).type.equals("Other")){
       String url = "https:abc.com&code=" + values.get(position).code + "&type="+ values.get(position).type;
       new HttpAsyncTask().execute(url);
       holder.info.setText(operator);
    }

将if更改为else if，它可以让您的应用提升效果。

Answer 2

好的，现在我明白了，对不起，我没有看到你声明持有人在底部。顺便说一句，如果你将holder声明为一个类字段，它将始终包含不同的视图，因为每次调用getView时它都会引用不同的视图。您应该将持有者引用传递给AsynTask。

更新 - 添加代码 这样做

public HttpAsyncTask(ViewHolder view) {
    myHolder = view;
}

@Override
protected void onPostExecute(String result) {
    try {
        JSONArray reader = new JSONArray(result);
        if (!(reader.isNull(0))) {
            myHolder.info.setText(reader.getJSONObject(0).getString("marks"));
            Log.d(TAG, "Marks" + marks);

        } else {
            myHolder.info.setText("Not Found");
        }
    } catch (JSONException j){
        j.printStackTrace();
    }

}

Update2将持有者传递给AsyncTask

new HttpAsyncTask(holder).execute(url);

在http请求android之后更新特定列表项

2 个答案: