Question

我只是要进入它。我建议使用此代码解决我几个小时前提出的问题，但此代码有错误。

public class ListView extends ListActivity {

    private ProgressDialog pDialog;

    JSONParsser jParser = new JSONParsser();
    ArrayList<HashMap<String, String>> questionList;

    private static String URI = "http://example.com/json";;

    //JSONObject json = jParser.getJSONFromURI(URI); 

     final String TAG_RESULTS = "ResultsSet";
     final String TAG_SUBJECT = "Subject";
     final String TAG_NUMANSWERS = "NumAnswers";
     final String TAG_QUESTION = "Question";
     final String TAG_QUESTION_CONTENT = "Content";
     final String TAG_QUESTION_CHOSENANSWER = "ChosenAnswer";
     final String TAG_QUESTION_ANSWERS = "Answers";

            JSONArray ResultsSet = null;


    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.listview);

    questionList = new ArrayList<HashMap<String, String>>();

    new LoadAllData().execute();

    android.widget.ListView lv = getListView();

    lv.setOnItemClickListener(new OnItemClickListener() {

        @Override
        public void onItemClick(AdapterView<?> parent, View view,int position, long id) {


        }
    });

}

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);

        if (resultCode == 100) {
            Intent intent = getIntent();
            finish();
            startActivity(intent);
        }
    }

    class LoadAllData extends AsyncTask<String, String, String> {

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            pDialog = new ProgressDialog(ListView.this);
            pDialog.setMessage("Loading Data. Please wait...");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(false);
            pDialog.show();
        }

        protected String doInBackground(String... args) {

            try {
                    JSONObject json = jParser.getJSONFromURI(URI);
                    ResultsSet = json.getJSONArray(TAG_RESULTS);

                   for(int i = 0; i < ResultsSet.length(); i++) {
                       JSONObject r = ResultsSet.getJSONObject(i);
                       String Subject = r.getString(TAG_SUBJECT);
                       String NumAnswers = r.getString(TAG_NUMANSWERS);

                       JSONObject Question = r.getJSONObject(TAG_QUESTION);
                       String Content = Question.getString(TAG_QUESTION_CONTENT);
                       String ChosenAnswer = Question.getString(TAG_QUESTION_CHOSENANSWER);
                       String Answers = Question.getString(TAG_QUESTION_ANSWERS);

                       HashMap<String, String> map = new HashMap<String, String>();

                       map.put(TAG_SUBJECT, Subject);
                       map.put(TAG_NUMANSWERS, NumAnswers);
                   }



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


        }


        protected void onPostExecute(String file_URI) {

            pDialog.dismiss();
            runOnUiThread(new Runnable() {
            public void run() {
                ListAdapter adapter = new SimpleAdapter(this, questionList,
                        R.layout.row,
                        new String[] { TAG_SUBJECT, TAG_NUMANSWERS }, new int[] {
                        R.id.Subject, R.id.NumAnswers });

                setListAdapter(adapter);

这些是这里的行

ListAdapter adapter = new SimpleAdapter(this, questionList,R.layout.row,
new String[] { TAG_SUBJECT, TAG_NUMANSWERS }, new int[] {
                            R.id.Subject, R.id.NumAnswers });

错误说构造函数 simpleAdapte(new Runnable(){}; ArrayList<HashMap<string,String>>,int,String[],int[]) is underfined 有人可以告诉我我需要做些什么才能解决这个问题。

Answer 1

在您的情况下，构造函数中的“this”指的是Runnable。改为使用'getBaseContext'。

ListAdapter adapter = new SimpleAdapter(getBaseContext, questionList,R.layout.row,
new String[] { TAG_SUBJECT, TAG_NUMANSWERS }, new int[] {
                        R.id.Subject, R.id.NumAnswers });

Android使用simpleadapter时出现问题

1 个答案: