我有一个Live Android应用程序,从市场上我收到了以下堆栈跟踪,我不知道为什么它会发生,因为它不是发生在应用程序代码中,而是由应用程序的一些或其他事件引起的(假设)
我没有使用片段,仍然有一个FragmentManager的参考。
如果有人能揭示一些隐藏的事实,以避免这类问题:
java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState
at android.app.FragmentManagerImpl.checkStateLoss(FragmentManager.java:1109)
at android.app.FragmentManagerImpl.popBackStackImmediate(FragmentManager.java:399)
at android.app.Activity.onBackPressed(Activity.java:2066)
at android.app.Activity.onKeyDown(Activity.java:1962)
at android.view.KeyEvent.dispatch(KeyEvent.java:2482)
at android.app.Activity.dispatchKeyEvent(Activity.java:2274)
at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchKeyEvent(PhoneWindow.java:1668)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at android.view.ViewGroup.dispatchKeyEvent(ViewGroup.java:1112)
at com.android.internal.policy.impl.PhoneWindow$DecorView.superDispatchKeyEvent(PhoneWindow.java:1720)
at com.android.internal.policy.impl.PhoneWindow.superDispatchKeyEvent(PhoneWindow.java:1258)
at android.app.Activity.dispatchKeyEvent(Activity.java:2269)
at com.android.internal.policy.impl.PhoneWindow$DecorView.dispatchKeyEvent(PhoneWindow.java:1668)
at android.view.ViewRoot.deliverKeyEventPostIme(ViewRoot.java:2851)
at android.view.ViewRoot.handleFinishedEvent(ViewRoot.java:2824)
at android.view.ViewRoot.handleMessage(ViewRoot.java:2011)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:132)
at android.app.ActivityThread.main(ActivityThread.java:4025)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:491)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
at dalvik.system.NativeStart.main(Native Method)
我有这个问题。但是我认为这个问题与commit和commitAllowStateLoss无关。
下面的堆栈跟踪和异常消息是关于commit()的。
java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState
at android.support.v4.app.FragmentManagerImpl.checkStateLoss(FragmentManager.java:1341)
at android.support.v4.app.FragmentManagerImpl.enqueueAction(FragmentManager.java:1352)
at android.support.v4.app.BackStackRecord.commitInternal(BackStackRecord.java:595)
at android.support.v4.app.BackStackRecord.commit(BackStackRecord.java:574)
但是这个异常是由onBackPressed()引起的
java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState
at android.support.v4.app.FragmentManagerImpl.checkStateLoss(Unknown Source)
at android.support.v4.app.FragmentManagerImpl.popBackStackImmediate(Unknown Source)
at android.support.v4.app.FragmentActivity.onBackPressed(Unknown Source)
它们都是由checkStateLoss()引起的
private void checkStateLoss() {
if (mStateSaved) {
throw new IllegalStateException(
"Can not perform this action after onSaveInstanceState");
}
if (mNoTransactionsBecause != null) {
throw new IllegalStateException(
"Can not perform this action inside of " + mNoTransactionsBecause);
}
mStateSaved在onSaveInstanceState之后为真。
这个问题很少发生。我从来没有遇到过这个问题。我不能再出现这个问题。
我找到了25517号
它可能在下列情况下发生
Back键在onSaveInstanceState之后,但在新活动开始之前被调用。
在代码中使用onStop()
我不确定问题的根源是什么。
所以我用了一个丑陋的方法。
@Override
public void onBackPressed() {
try{
super.onBackPressed();
}catch (IllegalStateException e){
// can output some information here
finish();
}
}
这是我迄今为止遇到的最愚蠢的错误。我有一个片段应用程序工作完美的API < 11,并强制关闭API > 11。
我真的不知道他们在saveInstance调用的活动生命周期内改变了什么,但我在这里是我如何解决这个问题的:
@Override
protected void onSaveInstanceState(Bundle outState) {
//No call for super(). Bug on API Level > 11.
}
我只是不调用.super(),一切都很好。我希望这将为您节省一些时间。
编辑:经过进一步研究,这是支持包中的一个已知错误。
如果你需要保存实例,并添加一些东西到你的outState Bundle,你可以使用以下方法:
@Override
protected void onSaveInstanceState(Bundle outState) {
outState.putString("WORKAROUND_FOR_BUG_19917_KEY", "WORKAROUND_FOR_BUG_19917_VALUE");
super.onSaveInstanceState(outState);
}
EDIT2:如果您试图在Activity在后台消失后执行事务,也可能会发生这种情况。为了避免这种情况,你应该使用commitAllowingStateLoss()
EDIT3: The above solutions were fixing issues in the early support.v4 libraries from what I can remember. But if you still have issues with this you MUST also read @AlexLockwood 's blog : Fragment Transactions & Activity State Loss
Summary from the blog post (but I strongly recommend you to read it) :
NEVER commit() transactions after onPause() on pre-Honeycomb, and onStop() on post-Honeycomb
Be careful when committing transactions inside Activity lifecycle methods. Use onCreate(), onResumeFragments() and onPostResume()
Avoid performing transactions inside asynchronous callback methods
Use commitAllowingStateLoss() only as a last resort
我有这个问题。但是我认为这个问题与commit和commitAllowStateLoss无关。
下面的堆栈跟踪和异常消息是关于commit()的。
java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState
at android.support.v4.app.FragmentManagerImpl.checkStateLoss(FragmentManager.java:1341)
at android.support.v4.app.FragmentManagerImpl.enqueueAction(FragmentManager.java:1352)
at android.support.v4.app.BackStackRecord.commitInternal(BackStackRecord.java:595)
at android.support.v4.app.BackStackRecord.commit(BackStackRecord.java:574)
但是这个异常是由onBackPressed()引起的
java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState
at android.support.v4.app.FragmentManagerImpl.checkStateLoss(Unknown Source)
at android.support.v4.app.FragmentManagerImpl.popBackStackImmediate(Unknown Source)
at android.support.v4.app.FragmentActivity.onBackPressed(Unknown Source)
它们都是由checkStateLoss()引起的
private void checkStateLoss() {
if (mStateSaved) {
throw new IllegalStateException(
"Can not perform this action after onSaveInstanceState");
}
if (mNoTransactionsBecause != null) {
throw new IllegalStateException(
"Can not perform this action inside of " + mNoTransactionsBecause);
}
mStateSaved在onSaveInstanceState之后为真。
这个问题很少发生。我从来没有遇到过这个问题。我不能再出现这个问题。
我找到了25517号
它可能在下列情况下发生
Back键在onSaveInstanceState之后,但在新活动开始之前被调用。
在代码中使用onStop()
我不确定问题的根源是什么。
所以我用了一个丑陋的方法。
@Override
public void onBackPressed() {
try{
super.onBackPressed();
}catch (IllegalStateException e){
// can output some information here
finish();
}
}
这对我很管用……我自己发现的…希望对你有所帮助!
1)不要有全局的“静态”FragmentManager / FragmentTransaction。
2) onCreate,总是初始化FragmentManager再次!
样本如下:-
public abstract class FragmentController extends AnotherActivity{
protected FragmentManager fragmentManager;
protected FragmentTransaction fragmentTransaction;
protected Bundle mSavedInstanceState;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mSavedInstanceState = savedInstanceState;
setDefaultFragments();
}
protected void setDefaultFragments() {
fragmentManager = getSupportFragmentManager();
//check if on orientation change.. do not re-add fragments!
if(mSavedInstanceState == null) {
//instantiate the fragment manager
fragmentTransaction = fragmentManager.beginTransaction();
//the navigation fragments
NavigationFragment navFrag = new NavigationFragment();
ToolbarFragment toolFrag = new ToolbarFragment();
fragmentTransaction.add(R.id.NavLayout, navFrag, "NavFrag");
fragmentTransaction.add(R.id.ToolbarLayout, toolFrag, "ToolFrag");
fragmentTransaction.commitAllowingStateLoss();
//add own fragment to the nav (abstract method)
setOwnFragment();
}
}