本文介绍了Android活动会重新创建自己的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我的应用通常可以正常运行，直到我在特定设备上遇到一个奇怪的问题.应用程式中有2个活动.在ActivityA内启动ActivityB之后，ActivityA毫无问题地启动.但是，在我通过按下硬件按钮或调用finish()返回到ActivityA之后；在ActivityB的closeButton内部，ActivityA会重新加载自身.它再次触发onCreate()并重新加载其所有内容.而且我不会改变手机的方向.这种奇怪的行为仅出现在15个手机上，超过1000个应用程序下载.
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.
仅在Galaxy S3 Android OS 4.1.2上会出现此问题.这也很奇怪.
您知道为什么会这样吗?
Do you have any idea why this is happening?
当我像这样在按钮监听器中启动新的活动时:
When I start a new Activity inside of button listener like this:
ActivityA.java (MesajlarListViewActivity)
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)
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.
}
不仅这两个活动都有此问题，所有活动在某些手机上的行为相同.
推荐答案
检查设置> 系统下是否不保留活动 >> 开发者选项> 应用已启用.
Check to see whether Don't keep activities under Settings > System > Developer options > Apps is enabled or not.
这篇关于Android活动会重新创建自己的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！