为什么AsyncTask执行应用程序总是强制停止？
有2个结果，首先是AsyncTask success access将强制停止的网址，如果failed to access网址将显示错误且不强制停止。
这是我的代码：
private void insertToDatabase(final String alamat) {
class SendPostReqAsyncTask extends AsyncTask<String, Void, String> {
@Override
protected void onPreExecute() {
myProgressDialog = new ProgressDialog(MainActivity.this);
myProgressDialog.setIndeterminate(true);
myProgressDialog.setMessage("Loading...");
myProgressDialog.setCancelable(true);
myProgressDialog.show();
}
@Override
protected String doInBackground(String... params) {
String text = null;
String urlATM = alamat;
try {
JSONArray data = new JSONArray(getJSONUrl(urlATM));
if(data.length()!=0){
HashMap<String, String> map;
for (int i = 0; i < data.length(); i++) {
JSONObject c = data.getJSONObject(i);
map = new HashMap<String, String>();
map.put("id_atm", c.getString("id_atm"));
map.put("id_bank", c.getString("id_bank"));
map.put("nama_bank", c.getString("nama_bank"));
map.put("latitude", c.getString("latitude"));
map.put("longitude", c.getString("longitude"));
map.put("name", c.getString("name"));
map.put("email", c.getString("email"));
MyArrListATM.add(map);
//end add marker
maps.addMarker(new MarkerOptions()
.title("ATM"+MyArrListATM.get(i)
.get("nama_bank"))
.snippet("24 Jam")
.position(new LatLng(
Double.parseDouble(MyArrListATM.get(i).get("latitude")),
Double.parseDouble(MyArrListATM.get(i).get("longitude")))));
}
myProgressDialog.dismiss();
}
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
text = e.getMessage();
}
//
return text;
}
@Override
protected void onPostExecute(String result) {
super.onPostExecute(result);
myProgressDialog.dismiss();
AlertDialog alertDialog = new AlertDialog.Builder(MainActivity.this).create();
alertDialog.setTitle("PERINGATAN");
alertDialog.setMessage("Error: "+result);
alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "TUTUP", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
alertDialog.show();
}
}
SendPostReqAsyncTask sendPostReqAsyncTask = new SendPostReqAsyncTask();
sendPostReqAsyncTask.execute(alamat);
}
并显示此代码的错误：
sendPostReqAsyncTask.execute(alamat);
logcat的：
07-15 15:33:53.196 19175-23224/com.emergency.e_place E/AndroidRuntime: FATAL EXCEPTION: AsyncTask #4
Process: com.emergency.e_place, PID: 19175
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:300)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
Caused by: java.lang.IllegalStateException: Not on the main thread
at maps.f.g.b(Unknown Source)
at maps.z.F.a(Unknown Source)
at maps.af.t.a(Unknown Source)
at vl.onTransact(:com.google.android.gms.DynamiteModulesB:167)
at android.os.Binder.transact(Binder.java:361)
at com.google.android.gms.maps.internal.IGoogleMapDelegate$zza$zza.addMarker(Unknown Source)
at com.google.android.gms.maps.GoogleMap.addMarker(Unknown Source)
at com.emergency.e_place.MainActivity$1SendPostReqAsyncTask.doInBackground(MainActivity.java:584)
at com.emergency.e_place.MainActivity$1SendPostReqAsyncTask.doInBackground(MainActivity.java:552)
at android.os.AsyncTask$2.call(AsyncTask.java:288)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)
at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
07-15 15:33:54.606 19175-19175/com.emergency.e_place E/WindowManager: android.view.WindowLeaked: Activity com.emergency.e_place.MainActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{41a95858 V.E..... R......D 0,0-471,144} that was originally added here
at android.view.ViewRootImpl.<init>(ViewRootImpl.java:451)
at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:267)
at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69)
at android.app.Dialog.show(Dialog.java:289)
at com.emergency.e_place.MainActivity$1SendPostReqAsyncTask.onPreExecute(MainActivity.java:559)
at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:587)
at android.os.AsyncTask.execute(AsyncTask.java:535)
at com.emergency.e_place.MainActivity.insertToDatabase(MainActivity.java:629)
at com.emergency.e_place.MainActivity.access$1000(MainActivity.java:77)
at com.emergency.e_place.MainActivity$17.onNavigationItemSelected(MainActivity.java:961)
at android.support.design.widget.NavigationView$1.onMenuItemSelected(NavigationView.java:136)
at android.support.v7.internal.view.menu.MenuBuilder.dispatchMenuItemSelected(MenuBuilder.java:811)
at android.support.v7.internal.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:153)
at android.support.v7.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:958)
at android.support.design.internal.NavigationMenuPresenter.onItemClick(NavigationMenuPresenter.java:187)
at android.widget.AdapterView.performItemClick(AdapterView.java:308)
at android.widget.AbsListView.performItemClick(AbsListView.java:1510)
at android.widget.AbsListView$PerformClick.run(AbsListView.java:3472)
at android.widget.AbsListView$3.run(AbsListView.java:4835)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:146)
at android.app.ActivityThread.main(ActivityThread.java:5511)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：3)
map.addMarker，dismiss dialog或用户界面的任何更改必须
doInBackground（Params ...），在后台线程上调用
因此，您应该删除myProgressDialog.dismiss();中的doInBackground
并将maps.addMarker...移至onPostExecute(Result)或onProgressUpdate(Progress...)（因为在UI线程上调用了onPostExecute和onProgressUpdate）
protected String doInBackground(String... params) {
...
//end add marker
MarkerOptions markerOptions = new MarkerOptions().title()....;
onProgressUpdate(markerOptions)
}
protected void onProgressUpdate(MarkerOptions... values) {
maps.addMarker(values);
}
protected void onPostExecute(String result) {
// or you can add all markers to maps in here
}
答案 1 :(得分：0)
您无法在后台线程中访问maps。您可以使用publishProgress并使用onProgressUpdate方法处理它。