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)  

当前回答

我认为在这些操作之前调用FragmentActivity.onStateNotSaved()可能是目前最好的选择。

其他回答

如果你试图在你的片段活动的onSaveInstanceState()被调用后执行片段转换,就会发生这样的异常。

发生这种情况的一个原因是,当一个活动停止时,如果你让一个AsyncTask(或线程)运行。

调用onSaveInstanceState()后的任何转换都可能丢失,如果系统回收活动的资源并稍后重新创建它。

当用户旋转屏幕以便加载与新方向相关的资源时,onSaveInstance将被调用。

有可能这个用户旋转了屏幕,然后按了后退按钮(因为也有可能这个用户在使用你的应用程序时摸不着他们的手机)

读 http://chris-alexander.co.uk/on-engineering/dev/android-fragments-within-fragments/

篇文章。 fragment. isresume()检查帮助我在onDestroyView w/o使用onSaveInstanceState方法。

I solved the issue with onconfigurationchanged. The trick is that according to android activity life cycle, when you explicitly called an intent(camera intent, or any other one); the activity is paused and onsavedInstance is called in that case. When rotating the device to a different position other than the one during which the activity was active; doing fragment operations such as fragment commit causes Illegal state exception. There are lots of complains about it. It's something about android activity lifecycle management and proper method calls. To solve it I did this: 1-Override the onsavedInstance method of your activity, and determine the current screen orientation(portrait or landscape) then set your screen orientation to it before your activity is paused. that way the activity you lock the screen rotation for your activity in case it has been rotated by another one. 2-then , override onresume method of activity, and set your orientation mode now to sensor so that after onsaved method is called it will call one more time onconfiguration to deal with the rotation properly.

你可以复制/粘贴这段代码到你的活动来处理它:

@Override
protected void onSaveInstanceState(Bundle outState) {       
    super.onSaveInstanceState(outState);

    Toast.makeText(this, "Activity OnResume(): Lock Screen Orientation ", Toast.LENGTH_LONG).show();
    int orientation =this.getDisplayOrientation();
    //Lock the screen orientation to the current display orientation : Landscape or Potrait
    this.setRequestedOrientation(orientation);
}

//A method found in stackOverflow, don't remember the author, to determine the right screen orientation independently of the phone or tablet device 
public int getDisplayOrientation() {
    Display getOrient = getWindowManager().getDefaultDisplay();

    int orientation = getOrient.getOrientation();

    // Sometimes you may get undefined orientation Value is 0
    // simple logic solves the problem compare the screen
    // X,Y Co-ordinates and determine the Orientation in such cases
    if (orientation == Configuration.ORIENTATION_UNDEFINED) {
        Configuration config = getResources().getConfiguration();
        orientation = config.orientation;

        if (orientation == Configuration.ORIENTATION_UNDEFINED) {
        // if height and widht of screen are equal then
        // it is square orientation
            if (getOrient.getWidth() == getOrient.getHeight()) {
                orientation = Configuration.ORIENTATION_SQUARE;
            } else { //if widht is less than height than it is portrait
                if (getOrient.getWidth() < getOrient.getHeight()) {
                    orientation = Configuration.ORIENTATION_PORTRAIT;
                } else { // if it is not any of the above it will defineitly be landscape
                    orientation = Configuration.ORIENTATION_LANDSCAPE;
                }
            }
        }
    }
    return orientation; // return value 1 is portrait and 2 is Landscape Mode
}

@Override
public void onResume() {
    super.onResume();
    Toast.makeText(this, "Activity OnResume(): Unlock Screen Orientation ", Toast.LENGTH_LONG).show();
    setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_SENSOR);
} 

我认为生命周期状态可以帮助防止这种崩溃从Android支持库v26.1.0开始,你可以有以下检查:

if (getLifecycle().getCurrentState().isAtLeast(Lifecycle.State.STARTED)){
  // Do fragment's transaction commit
}

或者你可以试试:

Fragment.isStateSaved()

更多信息请点击这里 https://developer.android.com/reference/android/support/v4/app/Fragment.html isStateSaved ()