我只是有一些非常简短的问题AsyncTask
看看这个我AsyncTask和它所在的班级
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";
final String TAG_COUNT = "count";
ProgressDialog pDialog;
LoadAllData mTask;
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>>();
mTask = new LoadAllData();
mTask.execute();
}
@Override
protected void onListItemClick(android.widget.ListView l, View v, int pos, long id) {
super.onListItemClick(l, v, pos, id);
HashMap<String, String> item = questionList.get(pos);
Intent i = new Intent(ListView.this, SingleListItem.class);
i.putExtra(TAG_QUESTION_SUBJECT, item.get(TAG_QUESTION_SUBJECT));
i.putExtra(TAG_QUESTION_CONTENT, item.get(TAG_QUESTION_CONTENT));
i.putExtra(TAG_QUESTION_CHOSENANSWER, item.get(TAG_QUESTION_CHOSENANSWER));
startActivity(i);
}
@Override
public void onBackPressed() {
if (mTask != null && mTask.getStatus() != AsyncTask.Status.FINISHED)
{
mTask.cancel(true);
}
super.onBackPressed();
}
@Override
protected void onDestroy() {
// TODO Auto-generated method stub
if (mTask != null && mTask.getStatus() != AsyncTask.Status.FINISHED)
{
mTask.cancel(true);
}
super.onDestroy();
}
@Override
protected void onPause() {
// TODO Auto-generated method stub
if (pDialog != null)
{
if(pDialog.isShowing())
{
pDialog.dismiss();
}
super.onPause();
}
}
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(true);
pDialog.show();
}
protected String doInBackground(String... args) {
pDialog.setOnCancelListener(new DialogInterface.OnCancelListener(){
public void onCancel(DialogInterface dialog) {
mTask.cancel(true);
finish();
}
});
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 {
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 ChosenAnswer = question.getString(TAG_QUESTION_CHOSENANSWER);
String Content = question.getString(TAG_QUESTION_CONTENT);
HashMap<String, String> map = new HashMap<String, String>();
map.put(TAG_QUESTION_SUBJECT, Subject);
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 null;
}
@Override
protected void onPostExecute(String file_URL) {
if(file_URL!=null && file_URL.equals("0")) {
pDialog.dismiss();
Toast.makeText(ListView.this, "No data found", Toast.LENGTH_SHORT).show();
finish();
}else{
if (pDialog != null && pDialog.isShowing()) pDialog.dismiss();
ListAdapter adapter = new SimpleAdapter(getBaseContext(), questionList,
R.layout.listelements,
new String[] { TAG_QUESTION_SUBJECT }, new int[] {
R.id.Subject,});
setListAdapter(adapter);
}}}
现在我想问的问题是，如果我AsyncTask从当前活动中取出并将其放入不同的文件中，它是否会使我的doInBackGround方法的执行更快。我问这个是因为当我AsyncTask执行时，它需要相当长的时间才能完成，而且在我的 logcat 中，这条消息09-24 20:12:55.928: I/Choreographer(824): Skipped 195 frames! The application may be doing too much work on its main thread.在执行时会填满我的整个 logcat AsyncTask。我只是想知道如果我移动它会有所不同。