【发布时间】：2013-02-27 12:39:11
【问题描述】：
我的应用需要从服务器获取数据。所以我在onPreExecute() 方法中显示ProgressDialog，在doInBackground() 方法中显示数据是从服务器加载的。
此时如果我改变方向，应用程序强制关闭。因为当前活动被销毁，doInBackground() 可能仍然引用旧活动。所以，我提到了this post，它讨论了同样的问题。但我不想使用android:configchanges，因为它不是首选。 androiddevelopersite 说这应该是最后的手段，而不是大多数应用程序的首选。
那么，有人可以用必要的代码 sn-ps 建议如何以我的应用不会强制关闭的方式处理这种情况吗？
Eidt：我的代码
public class DataListActivity extends BaseActivity {
private ArrayList<String> valueslist;
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.listlayout);
new LoadAsync().execute();
}
class LoadAsync extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
progressDialog = new ProgressDialog(DataListActivity.this);
progressDialog.setMessage("Loading...");
progressDialog.setIndeterminate(false);
progressDialog.setCancelable(false);
progressDialog.show();
}
/**
* getting All datafrom url
* */
protected String doInBackground(String... args) {
//Here I am doing httppost request.
try{
// looping through All data that I got from the server
for (int i = 0; i < subCategoriesJson.length(); i++) {
JSONObject jsonobj = subCategoriesJson.getJSONObject(i);
// Storing each json item in variable
String item = jsonobj.getString("data");
valueslist.add(item);
}
return "1";
}
else {
return null;
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
protected void onPostExecute(String msg) {
if( msg != null && msg.equals("1"))
{
progressDialog.dismiss();
runOnUiThread(new Runnable() {
public void run() {
//Updating parsed json data to Listview
ListView listView = (ListView)findViewById(R.id.list1);
ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(getApplicationContext(),R.layout.list_item, valueslist);
listView.setAdapter(arrayAdapter);
listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
String selectedthing = valueslist.get(position);
}
});
}
});
}else
{
//There is no data.
}
}
}
}
注意：我提供了这些信息，尽管这不是这个问题所必需的。我的活动有两个布局文件。一个用于portrait，另一个用于layout-land 文件夹中的landscape 模式。
下面是 logcat 窗口：
02-27 19:54:40.294: E/WindowManager(11710): Activity com.example.DataList has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@40555388 that was originally added here
02-27 19:54:40.294: E/WindowManager(11710): android.view.WindowLeaked: Activity com.example.prog.DataList has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView@40555388 that was originally added here
02-27 19:54:40.294: E/WindowManager(11710): at android.view.ViewRoot.<init>(ViewRoot.java:277)
02-27 19:54:40.294: E/WindowManager(11710): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:148)
02-27 19:54:40.294: E/WindowManager(11710): at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:91)
02-27 19:54:40.294: E/WindowManager(11710): at android.view.Window$LocalWindowManager.addView(Window.java:433)
02-27 19:54:40.294: E/WindowManager(11710): at android.app.Dialog.show(Dialog.java:265)
02-27 19:54:40.294: E/WindowManager(11710): at com.example.prog.DataList$LoadAsync.onPreExecute(DataList.java:77)
02-27 19:54:40.294: E/WindowManager(11710): at android.os.AsyncTask.execute(AsyncTask.java:391)
02-27 19:54:40.294: E/WindowManager(11710): at com.example.prog.DataList.onCreate(DataList.java:52)
02-27 19:54:40.294: E/WindowManager(11710): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1072)
02-27 19:54:40.294: E/WindowManager(11710): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1794)
02-27 19:54:40.294: E/WindowManager(11710): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1851)
02-27 19:54:40.294: E/WindowManager(11710): at android.app.ActivityThread.access$1500(ActivityThread.java:132)
02-27 19:54:40.294: E/WindowManager(11710): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1038)
02-27 19:54:40.294: E/WindowManager(11710): at android.os.Handler.dispatchMessage(Handler.java:99)
02-27 19:54:40.294: E/WindowManager(11710): at android.os.Looper.loop(Looper.java:150)
02-27 19:54:40.294: E/WindowManager(11710): at android.app.ActivityThread.main(ActivityThread.java:4277)
02-27 19:54:40.294: E/WindowManager(11710): at java.lang.reflect.Method.invokeNative(Native Method)
02-27 19:54:40.294: E/WindowManager(11710): at java.lang.reflect.Method.invoke(Method.java:507)
02-27 19:54:40.294: E/WindowManager(11710): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
02-27 19:54:40.294: E/WindowManager(11710): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
02-27 19:54:40.294: E/WindowManager(11710): at dalvik.system.NativeStart.main(Native Method)
02-27 19:54:40.294: E/ResourceType(11710): Style contains key with bad entry: 0x010102f3
02-27 19:54:40.294: E/ResourceType(11710): Style contains key with bad entry: 0x01010300
02-27 19:54:40.294: E/ResourceType(11710): Style contains key with bad entry: 0x0101039c
【问题讨论】：
-
发布所有logcat数据...然后我们可以了解问题是什么或发生强制关闭时抛出了哪些异常。
-
一些代码也可能有用。因为当我有一个活动的 ProgressDialog 时，我可以毫无问题地切换方向。
标签： android networking screen-orientation operation