问题
My app normally works just fine, until I face a strange problem on specific device. There are 2 activities in App. After I start ActivityB inside of ActivityA, ActivityA starts with no issue. However, after I go back to the ActivityA with pushing back hardware button or calling finish(); inside of closeButton in ActivityB, ActivityA reloads itself. It triggers onCreate() again and reloads all its contents. And I'm not changing orientation of phone. This strange behavior only appears in 15 phones over 1.000 download of app.
This problem only occurs on Galaxy S3 Android OS 4.1.2. And this is also strange.
Do you have any idea why this is happening?
When I start a new Activity inside of button listener like this:
ActivityA.java (MesajlarListViewActivity)
public class MesajlarListViewActivity extends TrackedActivity {
Context context = null;
// contacts JSONArray
JSONArray contacts = null;
ArrayList<Message> productArray = new ArrayList<Message>();
private ProductAdapter adapter;
private ListView productList;
private Runnable viewOrders;
private HoloProgressIndicator profilInfoProgress = null;
ImageView kapatButton = null;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.mesajlar_list);
context = this;
kapatButton = (ImageView) findViewById(R.id.kapat_button);
/* kapat button onclick listener. */
// =================================================================================================================
kapatButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View view)
{
// Set vibration on touch.
KnetGenericClass.vibratePhone(context);
finish();
}
});
// =================================================================================================================
//Progress bar.
profilInfoProgress = (HoloProgressIndicator) findViewById(R.id.profil_info_progress);
// cheking internet connectivity.
if(KnetGenericClass.checkInternetConnection(context))
{
// start task!
/* internet var ise web service baglantisi kurmaya baslayabiliriz. */
startActivityIndicatorWithThread();
}
else
{
KnetGenericClass.printErrorMessage(context, "Bağlantı Hatası",
"Lütfen internet bağlantınızı kontrol ediniz.");
}
productList = (ListView) findViewById(R.id.product_list);
adapter = new ProductAdapter(this, R.layout.message_row, productArray);
productList.setAdapter(adapter);
// When user click a view on list view new page is appearing.
productList.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id)
{
// Set vibration on touch.
KnetGenericClass.vibratePhone(context);
/* Navigate to message detay activity class with ilan ID. */
Intent myIntent = new Intent(view.getContext(), MesajDetayActivity.class);
myIntent.putExtra("messageID", productArray.get(position).getId());
startActivity(myIntent);
// setting image of clicked message null.
RelativeLayout relativeLayout = (RelativeLayout) view;
ImageView unreadedImageView = (ImageView) relativeLayout.findViewById(R.id.unreaded_image);
unreadedImageView.setImageResource(0);
}
});
}
public class ProductAdapter extends ArrayAdapter<Message> {
ArrayList<Message> items;
public ProductAdapter(Context context, int textViewResourceId, ArrayList<Message> objects) {
super(context, textViewResourceId, objects);
this.items = objects;
}
@Override
public View getView(int position, View convertView, ViewGroup parent)
{
if(convertView == null)
{
LayoutInflater vi = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = vi.inflate(R.layout.message_row, null);
}
ImageView unreadedImageView = (ImageView) convertView.findViewById(R.id.unreaded_image);
TextView productName = (TextView) convertView.findViewById(R.id.product_name);
TextView productDetail = (TextView) convertView.findViewById(R.id.product_detail);
// TextView productDate = (TextView)
// convertView.findViewById(R.id.product_date);
TextView sentDate = (TextView) convertView.findViewById(R.id.product_date);
productName.setText(items.get(position).getSender());
productDetail.setText(items.get(position).getTitle());
// String bodyNoHTML = items.get(position).getBody();
if(items.get(position).getIsReaded())
{
unreadedImageView.setImageResource(0);
}
else
{
unreadedImageView.setImageResource(R.drawable.bluedot);
}
String dateStr = items.get(position).getSentDate();
try
{
sentDate.setText(dateStr.substring(6, 8) + "." + dateStr.substring(4, 6) + "." + dateStr.substring(0, 4)
+" "+dateStr.substring(8, 10)+":"+dateStr.substring(10, 12));
}
catch(Exception e)
{
sentDate.setText("");
}
return convertView;
}
}// @end of product adapter class.
/* web service'e baglanti kurulan methodu threadin icerisinde cagiriyoruz. */
public void startActivityIndicatorWithThread()
{
// ==============================================================================================
// getting ilan details into arraylist.
// setting up thread.
viewOrders = new Runnable() {
public void run()
{
getMessageListFromWebService();
}
};
Thread thread = new Thread(null, viewOrders, "MagentoBackground");
thread.start();
profilInfoProgress.start();
// ==============================================================================================
// @end of the thread declaration.
}
public void getMessageListFromWebService()
{
// Creating JSON Parser instance
JSONParser jParser = new JSONParser(context);
// getting JSON string from URL
JSONArray jsonArray = jParser.getAuthorizedInfoFromUrlToJSONArray(
WebServiceInfo.getKnetWebServiceLink()+"/API/Member/GetInboxMessageList", MainActivity.getAccessToken());
// if json is null then there is a problem.
if(jsonArray == null)
{
// if json array is null then print error message.
runOnUiThread(showAlertMessage);
runOnUiThread(returnRes);
return;
}
try
{
// Eger aranilan kritere gore ilan yok ise hata mesaji basiyoruz.
if(jsonArray.length() == 0)
{
// if json array is null then print error message.
runOnUiThread(showAlertIlanYokMessage);
runOnUiThread(returnRes);
return;
}
// looping through All Contacts
for (int i = 0; i < jsonArray.length(); i++)
{
JSONObject c = jsonArray.getJSONObject(i);
// Storing each json item in variable
// String id = c.getString(TAG_ID);
String id = c.getString("Id");
String sender = c.getString("Sender");
// String body = c.getString("Body");
String title = c.getString("Title");
String sentDate = c.getString("SentDate");
Boolean isReaded = c.getBoolean("IsRead");
Message productObject = new Message(id, sender, "", title, sentDate, isReaded);
productArray.add(productObject);
}
}
catch (Exception e)
{
Log.e("BACKGROUND_PROC", e.getMessage());
}
runOnUiThread(returnRes);
}
// @end of thread.
private Runnable returnRes = new Runnable() {
public void run()
{
profilInfoProgress.stop();
adapter.notifyDataSetChanged();// refreshing data over adapter in
// list view.
}
};
// @end of thread.
private Runnable showAlertMessage = new Runnable() {
public void run()
{
// Bu hata genelde linkteki problemden, servera ulasilamamasindan
// veya timeouttan meydana gelir.
Toast.makeText(getApplicationContext(),
"Mesajlar alınamadı lütfen daha sonra tekrar deneyiniz.",
Toast.LENGTH_LONG).show();
}
};
private Runnable showAlertIlanYokMessage = new Runnable() {
public void run()
{
// Bu hata aranilan kelimeye gore ilan bulunamazsa gelir.
Toast.makeText(getApplicationContext(),
"Mesajlar bulunamadı.",
Toast.LENGTH_LONG).show();
}
};
}
========================================================================
ActivityB.java (MesajDetayActivity.java)
public class MesajDetayActivity extends TrackedActivity {
private HoloProgressIndicator profilInfoProgress = null;
TextView titleTextView = null;
TextView senderTextView = null;
TextView dateTextView = null;
WebView bodyWebView = null;
Message messageObject = null;
String messageID = null;
ImageView kapatButton = null;
Context context;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.mesajdetaylari);
context = this;
kapatButton = (ImageView) findViewById(R.id.kapat_button);
/* kapat button onclick listener. */
// =================================================================================================================
kapatButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View view)
{
// Set vibration on touch.
KnetGenericClass.vibratePhone(context);
finish();
}
});
// =================================================================================================================
//Progress bar.
profilInfoProgress = (HoloProgressIndicator) findViewById(R.id.profil_info_progress);
Bundle extras = getIntent().getExtras();
if(extras != null)
{
messageID = extras.getString("messageID");
}
titleTextView = (TextView) findViewById(R.id.title_textview);
senderTextView = (TextView) findViewById(R.id.sender_textview);
dateTextView = (TextView) findViewById(R.id.date_textview);
bodyWebView = (WebView) findViewById(R.id.mesaj_webView);
// Show the ProgressDialog on this thread
profilInfoProgress.start();
// Start a new thread that will download all the data
new MakeItTask().execute();
}
// Async task.
private class MakeItTask extends AsyncTask<String, Void, Object> {
protected Object doInBackground(String... args)
{
Log.i("MyApp", "Background thread starting");
// This is where you would do all the work of downloading your data
// getting message detay
/* connect to web service */
getMessageDetayFromWebService();
return null;
}
protected void onPostExecute(Object result)
{
// Pass the result data back to the main activity
// TakipListeActivity.this.data = result;
try
{
titleTextView.setText("Başlık: " + messageObject.getTitle());
senderTextView.setText("Gönderen: " + messageObject.getSender());
dateTextView.setText("Tarih: " + messageObject.getSentDate().substring(6, 8) + "."
+ messageObject.getSentDate().substring(4, 6) + "."
+ messageObject.getSentDate().substring(0, 4));
if(!messageObject.getBody().contains("img"))
{
bodyWebView.loadDataWithBaseURL(null, messageObject.getBody(), "text/html", "UTF-8", null);
}
}
catch (Exception e)
{
Log.e(CONNECTIVITY_SERVICE, "Mesaj Detayi bilgileri basilamadi.");
}
profilInfoProgress.stop();
}
}
/* web service'e baglanti kurulan methodu threadin icerisinde cagiriyoruz. */
public void getMessageDetayFromWebService()
{
// Creating JSON Parser instance
JSONParser jParser = new JSONParser(context);
// getting JSON string from URL
JSONObject jsonObject = jParser.getAuthorizedInfoFromUrlToJSONObject(
WebServiceInfo.getKnetWebServiceLink()+"/API/Member/GetInboxMessage/" + messageID, MainActivity.getAccessToken());
// if json is null then there is a problem.
if(jsonObject == null)
{
return;
}
try
{
String title = jsonObject.getString("Title");
String id = jsonObject.getString("Id");
String sender = jsonObject.getString("Sender");
String date = jsonObject.getString("SentDate");
String body = jsonObject.getString("Body");
messageObject = new Message(id, sender, body, title, date, true);
}
catch (Exception e)
{
Log.e("BACKGROUND_PROC", e.getMessage());
}
}// @end of getIlanDetayFromWebService.
}
Edit: Not only these two activities have this problem, all the activities acting same behavior on some phones.
回答1:
Check to see whether Don't keep activities under Settings > System > Developer options > Apps is enabled or not.
回答2:
The Activity documentation (http://developer.android.com/reference/android/app/Activity.html) says the following about the lifecycle of a background activity:
A background activity (an activity that is not visible to the user and has been paused) is no longer critical, so the system may safely kill its process to reclaim memory for other foreground or visible processes. If its process needs to be killed, when the user navigates back to the activity (making it visible on the screen again), its onCreate(Bundle) method will be called with the savedInstanceState it had previously supplied in onSaveInstanceState(Bundle) so that it can restart itself in the same state as the user last left it.
In other words, ActivityA may or may not be destroyed by the operating system while ActivityB is active, so this situation has to be handled in the code. If ActivityA has been destroyed, onCreate(Bundle) will be called, when the user presses the back button in ActivityB.
回答3:
There's an Android developer setting called "Do not keep activities". The description for this option is "Destroy every activity as soon as the user leaves it." This sounds like a good description of what you're seeing, and since you're only seeing it on a few phones the idea that this is caused by a non-default system setting seems plausible.
Ideally your app would still work in this scenario, even if less optimally. But if this setting is a problem for your app, you may wish to document this problem for your users.
回答4:
Have you tried changing the launchmode in the Android Manifest? Try adding this to your Activity declaration:
android:launchMode="singleTask"
Next, try using startActivityForResult, instead of startActivity. This will force Activity A to call its onActivityResult(int, int, Intent) method when Activity B finishes - which may skip this (buggy) call to onCreate. Then, in Activity A, implement the method to do something (such as printing a debug statement):
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
Log.i("Test", "Did this work???");
//TODO send notification to your server to verify this works?
}
回答5:
I do not see any problem in this behaviour.
In case you wish to preserve the state of ActivityA, make use of the methods onSaveInstanceState and onRestoreInstanceState. See Activity Lifecycle at http://developer.android.com/reference/android/app/Activity.html#ActivityLifecycle for more details.
See also https://stackoverflow.com/a/10492967/332210 for a deeper understanding.
回答6:
You can try one thing provide your layout in onCreate() and do the rest of the work in onStart() ?? if it works??
LIKE:
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.show);
}
and
@Override
protected void onStart() {
// TODO Auto-generated method stub
super.onStart();
Log.i(TAG, "On Start .....");
}
See Activity Lifecycle
回答7:
Perhaps you should use
Intent startIntent = new Intent(view.getContext(), ActivityB.class);
startActivity(startIntent);
finish() ;
And
Intent startIntent = new Intent(view.getContext(), ActivityA.class);
startActivity(startIntent);
finish() ;
each time you go back or forward.
回答8:
It too faced the exact problem and solved issue by Using android:launchMode="standard" in activity of manifest.
回答9:
Override onStart() and onResume method in Activity A and check if the problem is still persist. and if possible please give your activtiy A and B code here.
回答10:
Activity A uses layout R.layout.mesajlar_list
Activity B uses layout R.layout.mesajdetaylari
But both have the following line of code:
kapatButton = (ImageView) findViewById(R.id.kapat_button);
Which layout is R.id.kapat_button in? Using the same id in different layouts is a very risky thing to do. I can't guarantee it's causing what you're seeing, but it is the sort of thing that may cause weird behaviour.
回答11:
I think it is not because of memory the limit.
https://www.box.com/s/7pd0as03bb8wwumuc9l9
You should test these two activities and check whether it is happening in this example too or not. Please share your AndroidManifest.xml file content too, it will help with debugging.
回答12:
I got this issue recently, and this make me annoyed. I think that issue around 2 options solution to check but useless.
About the setting "Don't keep activities" corrected here, I used this code to check that it optional checked or not (my test device customize base on version 2.3.5 and not show this option):
private boolean isAlwaysFinishActivitiesOptionEnabled() {
int alwaysFinishActivitiesInt = 0;
if (Build.VERSION.SDK_INT >= 17) {
alwaysFinishActivitiesInt = Settings.System.getInt(getApplicationContext().getContentResolver(), Settings.Global.ALWAYS_FINISH_ACTIVITIES, 0);
} else {
alwaysFinishActivitiesInt = Settings.System.getInt(getApplicationContext().getContentResolver(), Settings.System.ALWAYS_FINISH_ACTIVITIES, 0);
}
if (alwaysFinishActivitiesInt == 1) {
return true;
} else {
return false;
}
}
Result check is false in my case. I also check the memory when running application and it nothing occur.
回答13:
you can use android:launchMode="singleTop"in manifest.
<activity
android:name=".MainActivity"
android:label="@string/app_name"
android:launchMode="singleTop"
android:configChanges="orientation|keyboardHidden|screenSize"
android:theme="@style/AppTheme.NoActionBar">
<intent-filter>
<action android:name="android.intent.action.MAIN"/>
<category android:name="android.intent.category.LAUNCHER"/>
</intent-filter>
</activity>
来源：https://stackoverflow.com/questions/15002531/android-activity-recreate-itself