Question

我终于让我的onListItemClick工作但是现在好像我设置为传递到下一个活动的数据没有通过，但活动仍然开始。我的应用程序不会崩溃或任何它只是加载活动，但我设置的数据似乎并不存在。我试过删除scrollview但数据仍然没有通过。

public class ListView extends ListActivity {    

    ArrayList<HashMap<String, String>> questionList;        

     final String TAG_RESULTS = "results";
     final String TAG_QUESTION_SUBJECT = "Subject";
     final String TAG_QUESTION_NUMANSWERS = "NumAnswers";
     final String TAG_QUESTION = "question";
     final String TAG_QUESTION_CONTENT = "Content";
     final String TAG_QUESTION_CHOSENANSWER = "ChosenAnswer";
     final String TAG_ANSWERS = "Answers";
     final String TAG_ANSWER = "Answer";    
     final String TAG_ANSWERS_CONTENT = "content";      
     final String TAG_QUERY = "query";

            JSONArray question = null;          
            android.widget.ListView lv;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState); 
        //setContentView(R.layout.listview);        
        questionList = new ArrayList<HashMap<String, String>>(); 
        new LoadAllData().execute();
    }

    @Override   
    protected void onListItemClick(android.widget.ListView l, View v, int pos, long id) {
         super.onListItemClick(l, v, pos, id);  

         String Subject = ((TextView) v.findViewById(R.id.Subject)).getText().toString();
         String Content = ((TextView) v.findViewById(R.id.Content)).getText().toString();
         String ChosenAnswer = ((TextView) v.findViewById(R.id.ChosenAnswer)).getText().toString();


         Intent i = new Intent(ListView.this, SingleListItem.class);
         i.putExtra(TAG_QUESTION_SUBJECT, Subject);
         i.putExtra(TAG_QUESTION_CONTENT, Content);
         i.putExtra(TAG_QUESTION_CHOSENANSWER, ChosenAnswer);
         startActivity(i);

            }     


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


        private Dialog pDialog;
        @Override
            protected void onPreExecute() {
            super.onPreExecute();
            ProgressDialog pDialog; 
            pDialog = new ProgressDialog(ListView.this);
            pDialog.setMessage("Loading Data. Please wait...");
            pDialog.setIndeterminate(false);
            pDialog.setCancelable(false);
            pDialog.show();
            if (pDialog != null && pDialog.isShowing()) pDialog.dismiss();
        }

        protected String doInBackground(String... args) {

            try {
                Intent in = getIntent();
                String searchTerm = in.getStringExtra("TAG_SEARCH");
                String query = URLEncoder.encode(searchTerm, "utf-8");
                String URL = "http://example.com";
                JSONParsser jParser = new JSONParsser();
                JSONObject json = jParser.readJSONFeed(URL);
                try {
                    //question = json.getJSONArray(TAG_QUESTION);


                    JSONArray questions = json.getJSONObject("all").getJSONArray("questions");

                    for(int i = 0; i < questions.length(); i++) {
                        JSONObject question = questions.getJSONObject(i);


                    String Subject = question.getString(TAG_QUESTION_SUBJECT);
                    String NumAnswers = question.getString(TAG_QUESTION_NUMANSWERS);
                    String ChosenAnswer = question.getString(TAG_QUESTION_CHOSENANSWER);
                    String Content = question.getString(TAG_QUESTION_CONTENT);

                    //JSONArray Answers = question.getJSONObject(TAG_ANSWERS).getJSONArray(TAG_ANSWER);


                    //JSONObject Answer = Answers.getJSONObject(0);

                    //String Content = Answer.getString(TAG_ANSWERS_CONTENT);

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

                               map.put(TAG_QUESTION_SUBJECT, Subject);
                               map.put(TAG_QUESTION_NUMANSWERS, NumAnswers);
                               map.put(TAG_QUESTION_CONTENT, Content);
                               map.put(TAG_QUESTION_CHOSENANSWER, ChosenAnswer);

                               questionList.add(map);


                    }


                } catch (JSONException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            } catch (UnsupportedEncodingException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }

                return TAG_QUESTION    ; 



        }
        @Override
        protected void onPostExecute(String file_URL) {
            ListAdapter adapter = new SimpleAdapter(getBaseContext(), questionList,
                        R.layout.listelements,
                        new String[] { TAG_QUESTION_SUBJECT, TAG_QUESTION_NUMANSWERS }, new int[] {
                        R.id.Subject, R.id.NumAnswers });

                setListAdapter(adapter); 


        }}}

SingleListItem活动：

public class SingleListItem extends Activity {

    TextView title;
    TextView question;
    TextView bestanswer;
    TextView subject;
    TextView content;
    TextView chosenanswer;

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

    title = (TextView) findViewById(R.id.Title1);
    question = (TextView) findViewById(R.id.Question1);
    bestanswer = (TextView) findViewById(R.id.BestAnswer1);
    subject = (TextView) findViewById(R.id.Subject1);
    content = (TextView) findViewById(R.id.Content1);
    chosenanswer = (TextView) findViewById(R.id.ChosenAnswer1);

    Intent i = getIntent();
    String Subject = i.getStringExtra("TAG_QUESTION_SUBJECT");
    String Content = i.getStringExtra("TAG_QUESTION_CONTENT");
    String ChosenAnswer = i.getStringExtra("TAG_QUESTION_CHOSENANSWER");
    subject.setText(Subject);
    content.setText(Content);
    chosenanswer.setText(ChosenAnswer);

    }
}

singlelistitem.xml：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/Title1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Title:"
        android:textAppearance="?android:attr/textAppearanceMedium"  />

    <TextView
        android:id="@+id/Subject1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="0.00"
        android:textAppearance="?android:attr/textAppearanceSmall" />

    <TextView
        android:id="@+id/Question1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Question:"
        android:textAppearance="?android:attr/textAppearanceMedium"  />

    <TextView
        android:id="@+id/Content1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="0.01"
        android:textAppearance="?android:attr/textAppearanceSmall" />

    <ScrollView
        android:id="@+id/scrollView1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" >
    </ScrollView>

    <TextView
        android:id="@+id/BestAnswer1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Best Answer:" 
        android:textAppearance="?android:attr/textAppearanceMedium" />

    <TextView
        android:id="@+id/ChosenAnswer1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="0.01"
        android:textAppearance="?android:attr/textAppearanceSmall"  />

</LinearLayout>

Answer 1

你的钥匙不一样。

你有这个

i.putExtra(TAG_QUESTION_SUBJECT, Subject);

和TAG_QUESTION_SUBJECT是“主题”

final String TAG_QUESTION_SUBJECT = "Subject";

你得到的部分是

String Subject = i.getStringExtra("TAG_QUESTION_SUBJECT"); // keys do not match
// must be "Subject"

将其更改为以下。密钥必须匹配

String Subject = i.getStringExtra("Subject");
String Content = i.getStringExtra("Content");
String ChosenAnswer = i.getStringExtra("ChosenAnswer");

Answer 2

您应该使用same keys进行发送和接收。 sending activity doesn't match with the keys接收活动中的部分密钥。

发送：

map.put("Question", Subject);
map.put("NumAnswer", NumAnswers);
map.put("content", Content);
map.put("chosenAnswer", ChosenAnswer);

收件人：

String Subject = question.getString("Question");
String NumAnswers = question.getString("NumAnswer");
String ChosenAnswer = question.getString("chosenAnswer");
String Content = question.getString("content");

Answer 3

您似乎已经在列表视图活动中命名了额外内容，例如“主题”，然后在单项活动中以不同方式引用它们：

String Subject = i.getStringExtra("TAG_QUESTION_SUBJECT");

可能会调查一下。

数据未从listview传递到活动

3 个答案: