Question

当我将我的应用推送到后台，并做一些其他的东西，如whatsapp或短信时，onResume它的效果很好。
但我最近发现，当我的应用程序在后台打开/启动Facebook应用程序时，我不知道会发生什么...
但是在休息时，应用程序行为不端...... 不要做他们需要做的事情，但是当我回到主页并回来时它工作正常请帮帮我..怎么解决???

包含所有邮件的Logcat（不带过滤器）

10-15 12:53:59.899: I/Adreno-EGL(32033): Remote Branch: quic/LNX.LA.3.5.1_RB1.1
10-15 12:53:59.899: I/Adreno-EGL(32033): Local Patches: NONE
10-15 12:53:59.899: I/Adreno-EGL(32033): Reconstruct Branch: AU_LINUX_ANDROID_LNX.LA.3.5.1_RB1.04.04.02.048.018 + f2fd134 +  NOTHING
10-15 12:53:59.924: D/OpenGLRenderer(32033): Enabling debug mode 0
10-15 12:54:00.000: V/AlarmManager(7677): sending alarm Alarm{42cfa490 type 3 android}
10-15 12:54:00.110: I/ActivityManager(7677): Displayed uk.org.humanfocus.hfi/.EvaluateTrainingActivity: +838ms
10-15 12:54:00.114: D/WifiStateMachine(7677): handleMessage: E msg.what=151572
10-15 12:54:00.114: D/WifiStateMachine(7677): processMsg: ConnectedState
10-15 12:54:00.114: D/WifiStateMachine(7677): processMsg: L2ConnectedState
10-15 12:54:02.258: V/AlarmManager(7677): sending alarm Alarm{42ebd600 type 1 com.facebook.katana}
10-15 12:54:02.274: V/AlarmManager(7677): sending alarm Alarm{42ec0ff0 type 1 com.android.chrome}
10-15 12:54:02.428: D/hardware_info(7386): hw_info_append_hw_type : device_name = speaker
10-15 12:54:03.011: W/BroadcastQueue(7677): Permission Denial: broadcasting Intent { act=android.net.conn.INET_CONDITION_ACTION flg=0x4000010 (has extras) } from null (pid=-1, uid=-1) requires com.facebook.permission.prod.FB_APP_COMMUNICATION due to registered receiver BroadcastFilter{41fdecd0 u0 ReceiverList{42b2f608 31941 com.facebook.katana/10103/u0 remote:429a17e8}}
10-15 12:54:03.011: W/BroadcastQueue(7677): Permission Denial: broadcasting Intent { act=android.net.conn.CONNECTIVITY_CHANGE flg=0x4000010 (has extras) } from null (pid=-1, uid=-1) requires com.facebook.permission.prod.FB_APP_COMMUNICATION due to registered receiver BroadcastFilter{41fdecd0 u0 ReceiverList{42b2f608 31941 com.facebook.katana/10103/u0 remote:429a17e8}}
10-15 12:54:03.118: D/WifiStateMachine(7677): handleMessage: E msg.what=151572
10-15 12:54:03.118: D/WifiStateMachine(7677): processMsg: ConnectedState
10-15 12:54:03.118: D/WifiStateMachine(7677): processMsg: L2ConnectedState
10-15 12:54:03.140: D/WifiStateMachine(7677): handleMessage: X
10-15 12:54:03.141: D/GCoreFlp(8174): Unknown pending intent to remove.
10-15 12:54:03.145: W/fb4a(:<default>):AbstractMqttPushService(31941): Attempt to start service that is already started
10-15 12:54:03.242: D/WifiStateMachine(7677): handleMessage: E msg.what=131155
10-15 12:54:03.242: D/WifiStateMachine(7677): processMsg: ConnectedState
10-15 12:54:03.243: D/WifiStateMachine(7677): processMsg: L2ConnectedState
10-15 12:54:03.245: D/WifiStateMachine(7677): handleMessage: X
10-15 12:54:03.319: D/dalvikvm(31941): GC_CONCURRENT freed 1833K, 9% free 20190K/22072K, paused 5ms+7ms, total 86ms
10-15 12:54:03.320: D/dalvikvm(31941): WAIT_FOR_CONCURRENT_GC blocked 68ms
10-15 12:54:03.323: W/MediaPlayer-JNI(31941): MediaPlayer finalized without being released
10-15 12:54:03.452: W/BroadcastQueue(7677): Permission Denial: broadcasting Intent { act=android.net.conn.CONNECTIVITY_CHANGE flg=0x4000010 (has extras) } from null (pid=-1, uid=-1) requires com.facebook.permission.prod.FB_APP_COMMUNICATION due to registered receiver BroadcastFilter{42b51d68 u0 ReceiverList{429feb50 31941 com.facebook.katana/10103/u0 remote:41fb8788}}
10-15 12:54:03.573: W/fb4a(:<default>):JACKSON_FALLBACK(31941): Using com.fasterxml.jackson.databind.deser.std.EnumDeserializer@42914bc8 to deserialize [simple type, class com.facebook.common.util.TriState]
10-15 12:54:03.587: W/fb4a(:<default>):JACKSON_FALLBACK(31941): Using com.fasterxml.jackson.databind.deser.std.EnumDeserializer@42bb3100 to deserialize [simple type, class com.facebook.contacts.graphql.contactprofiletype.ContactProfileType]
10-15 12:54:03.957: D/dalvikvm(31941): GC_CONCURRENT freed 3400K, 15% free 20455K/23952K, paused 4ms+7ms, total 88ms
10-15 12:54:03.957: D/dalvikvm(31941): WAIT_FOR_CONCURRENT_GC blocked 75ms
10-15 12:54:04.099: W/fb4a(:<default>):JACKSON_FALLBACK(31941): Using BeanSerializer for com.facebook.katana.newbookmark.qe.NewBookmarkConfig to serialize class com.facebook.katana.newbookmark.qe.NewBookmarkConfig
10-15 12:54:04.119: D/WifiStateMachine(7677): handleMessage: E msg.what=151572
10-15 12:54:04.120: D/WifiStateMachine(7677): processMsg: ConnectedState
10-15 12:54:04.120: D/WifiStateMachine(7677): processMsg: L2ConnectedState
10-15 12:54:04.124: D/WifiStateMachine(7677): handleMessage: X
10-15 12:54:04.177: W/fb4a(:<default>):JACKSON_FALLBACK(31941): Using com.fasterxml.jackson.databind.deser.std.EnumDeserializer@42a30980 to deserialize [simple type, class com.facebook.platform.webdialogs.PlatformWebViewActionManifest$FetchState]
10-15 12:54:04.197: I/dalvikvm(31941): Could not find method com.android.internal.widget.ILockSettings$Stub.a, referenced from method com.facebook.keyguardtype.LockSettingsServiceKeyguardTypeResolver.b
10-15 12:54:04.197: W/dalvikvm(31941): VFY: unable to resolve static method 5338: Lcom/android/internal/widget/ILockSettings$Stub;.a (Landroid/os/IBinder;)Lcom/android/internal/widget/ILockSettings;
10-15 12:54:04.197: D/dalvikvm(31941): VFY: replacing opcode 0x71 at 0x0023
10-15 12:54:04.440: I/SBar.NetworkController(7758): onSignalStrengthsChanged SignalStrength: 19 0 -120 -160 -120 -1 -1 99 2147483647 2147483647 2147483647 2147483647 2147483647 gsm|lte 0 -108 -1 false 5 5 0 0 0 99 99 99 5 level=5
10-15 12:54:04.814: V/WebViewChromiumFactoryProvider(31941): Binding Chromium to main looper Looper (main, tid 1) {41f8cbd0}
10-15 12:54:04.815: I/LibraryLoader(31941): Expected native library version number "",actual native library version number ""
10-15 12:54:04.816: I/chromium(31941): [INFO:library_loader_hooks.cc(116)] Chromium logging enabled: level = 0, default verbosity = 0
10-15 12:54:04.817: I/BrowserStartupController(31941): Initializing chromium process, renderers=0
10-15 12:54:04.822: E/AudioManagerAndroid(31941): BLUETOOTH permission is missing!
10-15 12:54:04.864: W/chromium(31941): [WARNING:proxy_service.cc(890)] PAC support disabled because there is no system implementation
10-15 12:54:05.121: D/WifiStateMachine(7677): handleMessage: E msg.what=151572
10-15 12:54:05.121: D/WifiStateMachine(7677): processMsg: ConnectedState
10-15 12:54:05.122: D/WifiStateMachine(7677): processMsg: L2ConnectedState

这是onResume（）

super.onResume();

        if (backgroundThreadRunning == true) {
            backgroundThreadRunning = false;
        }

        if (Constants.isVideoEditing)
            editingProgress.setVisibility(View.VISIBLE);
        else
            editingProgress.setVisibility(View.GONE);

        if (Constants.isAudioProcessing)
            addAudioProgress.setVisibility(View.VISIBLE);
        else
            addAudioProgress.setVisibility(View.GONE);

        if (isHomeKeyPressed() && !(isRecentActivity)) {
            isRecentActivity = false;
            homeKeyPressed(false);
            AlertDialog.Builder ab = new AlertDialog.Builder(
                    CreateTrainingActivity.this);
            ab.setMessage(
                    "Due to Other Application Launches, video process will be cancelled!\nAre you sure you want to cancel?")
                    .setPositiveButton("Yes", dialogClickListener)
                    .setNegativeButton("No", dialogClickListener).show();
        }

    };

编辑：我如何修复问题

我在onResume()方法

中编写了这段代码

try {
    // check if any view exists on current view
    style = ((Button) findViewById(R.id.xyz_button));   
} catch (Exception e) {
    // Button was not found
    // It means, your button doesn't exist on the "current" view
    // It was freed from the memory, therefore stop of activity was performed
    // In this case I restart my app
    Intent i = new Intent();
    i.setClass(getApplicationContext(), MainActivity.class);
    i.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
    startActivity(i);
    // Show toast to the user
    Toast.makeText(getApplicationContext(), "Data lost due to excess use of other apps", Toast.LENGTH_LONG).show();
}

Answer 1

一行：由于Android操作系统需要Facebook应用程序的内存，因此您的某些活动变量似乎已从内存中释放出来。

解释：当前台应用程序需要的内存多于可用内存时，Android会从后台运行的应用程序中释放一些内存。前台任务的优先级始终高于后台应用程序。

因此，应用程序在后台运行时可能发生的情况是，它的某些变量已丢失了您在onResume（）中使用的值。因此，当您再次将应用程序置于前台并且由于某些代码无法正常工作时，它们将保留错误的值或默认值（您可以使用Sysout进行检查），因为它们会重新创建。

Answer 2

在这个问题上给我50美分。捕获异常确实是一种可能性，但处理活动被系统杀死的活动问题的正确方法是在android中的常见问题，根据谷歌的解决方案是：

onPause（）是您处理离开活动的用户的地方。最重要的是，此时用户所做的任何更改都应提交（通常是持有数据的ContentProvider）。

重点是我的。但这意味着Android生命周期的设计是为了在正常条件下onPause应该被调用为Activity或Fragment被发送到后台。他们在几个android documentation pages中暗示了这一点：

当您的活动进入暂停状态时，系统会调用您的活动上的onPause（）方法，该方法可让您停止暂停时不应继续的持续操作（例如视频）或保留任何应永久保留的信息保存，以防用户继续离开您的应用。如果用户从暂停状态返回到您的活动，系统将恢复它并调用onResume（）方法。

注意：当您的活动收到对onPause（）的调用时，可能表示该活动暂停一段时间，并且用户可能会将焦点返回到您的活动。但是，它通常是用户离开您活动的第一个迹象。

但最有可能帮助你的资源是这两个：

http://developer.android.com/training/basics/activity-lifecycle/stopping.html

http://developer.android.com/training/basics/activity-lifecycle/recreating.html

您丢失的资源可能发生的事情是：

当您的活动收到对onStop（）方法的调用时，它将不再可见，并且应该释放用户未使用时几乎不需要的所有资源。一旦您的活动停止，系统可能会在需要恢复系统内存时销毁该实例。 ... 默认情况下，系统使用Bundle实例状态来保存活动布局中每个View对象的信息（例如输入EditText对象的文本值）。因此，如果您的活动实例被销毁并重新创建，则布局的状态将恢复到之前的状态，而您无需代码。但是，您的活动可能包含您要恢复的更多状态信息，例如跟踪用户在活动中的进度的成员变量。

注意：为了让Android系统恢复活动中的视图状态，每个视图必须具有唯一的ID，由android：id属性提供。

要保存有关活动状态的其他数据，必须覆盖onSaveInstanceState（）回调方法。系统在用户离开您的活动时调用此方法，并将其传递给Bundle对象，该对象将在您的活动意外销毁时保存。如果系统必须稍后重新创建活动实例，它会将相同的Bundle对象传递给onRestoreInstanceState（）和onCreate（）方法。

正确的解决方案是根据需要覆盖和实现Activity / Fragment的生命周期方法。

Google给出的两个例子：

    static final String STATE_SCORE = "playerScore";
static final String STATE_LEVEL = "playerLevel";
...

@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
    // Save the user's current game state
    savedInstanceState.putInt(STATE_SCORE, mCurrentScore);
    savedInstanceState.putInt(STATE_LEVEL, mCurrentLevel);

    // Always call the superclass so it can save the view hierarchy state
    super.onSaveInstanceState(savedInstanceState);
}
Caution: Always call the superclass implementation of onSaveInstanceState() so the default implementation can save the state of the view hierarchy.

反向恢复操作：

public void onRestoreInstanceState(Bundle savedInstanceState) {
    // Always call the superclass so it can restore the view hierarchy
    super.onRestoreInstanceState(savedInstanceState);

    // Restore state members from saved instance
    mCurrentScore = savedInstanceState.getInt(STATE_SCORE);
    mCurrentLevel = savedInstanceState.getInt(STATE_LEVEL);
}

Answer 3

希望您已经解决了这个问题，但您的代码中存在错误，可能是相关的：

if (backgroundThreadRunning = true) {
    backgroundThreadRunning = false;
}

您要分配而不是在“if”语句中进行比较。应该是：

if (backgroundThreadRunning == true) {
    backgroundThreadRunning = false;
}

或

if (backgroundThreadRunning) {
    backgroundThreadRunning = false;
}

Android - 执行停止未恢复的活动

3 个答案: