我正从表学生中检索数据（姓名，结果） 使用以下代码：
public class SelectActivity extends ActionBarActivity {
JSONArray jsonArray = null;
TextView tv_select;
ProgressDialog pDialog;
JSONParser jsonParser = new JSONParser();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_select);
tv_select =(TextView)findViewById(R.id.tv_select);
new LoadAllStudents().execute();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_select, menu);
return true;
}
class LoadAllStudents extends AsyncTask<String,String,String>
{
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(SelectActivity.this);
pDialog.setMessage("Loading data. Please wait...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
@Override
protected void onPostExecute(String s) {
super.onPostExecute(s);
if(pDialog!=null)
{
pDialog.dismiss();
pDialog =null;
}
}
@Override
protected String doInBackground(String... args) {
// List<NameValuePair> params = new ArrayList<NameValuePair>();
JSONObject json = jsonParser.getJSONFromUrl(app_url);
String studString ="";
try {
JSONArray student = json.getJSONArray("data");
for (int i= 0;i<student.length();i++)
{
JSONObject json1 =null;
try
{
json1 = student.getJSONObject(i);
studString = studString+
"Name"+ json1.getString("name")+"\n"+"Result"+json1.getString("result")+"\n";
}catch (JSONException e)
{
e.printStackTrace();
}
}
tv_select.setText(studString);
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
未能发出以下错误：
SelectActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{41914d60 V.E..... R......D 0,0-684,192} that was originally added here
android.view.WindowLeaked: Activity com.example.shubham.helloworld.SelectActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{41914d60 V.E..... R......D 0,0-684,192} that was originally added here
at android.view.ViewRootImpl.<init>(ViewRootImpl.java:409)
at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:218)
at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69)
at android.app.Dialog.show(Dialog.java:281)
at com.example.shubham.helloworld.SelectActivity$LoadAllStudents.onPreExecute(SelectActivity.java:57)
at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:586)
at android.os.AsyncTask.execute(AsyncTask.java:534)
at com.example.shubham.helloworld.SelectActivity.onCreate(SelectActivity.java:35)
at android.app.Activity.performCreate(Activity.java:5122)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1081)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2270)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2358)
at android.app.ActivityThread.access$600(ActivityThread.java:156)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1340)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:153)
at android.app.ActivityThread.main(ActivityThread.java:5297)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
at dalvik.system.NativeStart.main(Native Method)