IllegalStateException on FragmentManager

Question

我的应用程序一直在许多Android平台(4.1，4.0.4，2.3.6)上报告这个问题。但我不能在手机上复制这个问题。我已经通过Google搜索过这个问题，但是堆栈跟踪似乎与我的不一样。

有人知道这个问题是怎么发生的吗？以及如何预防呢？或者我如何复制这个错误？谢谢。

堆栈跟踪：

java.lang.IllegalStateException: Can not perform this action after onSaveInstanceState
at android.support.v4.app.FragmentManagerImpl.checkStateLoss(FragmentManager.java:1327)
at android.support.v4.app.FragmentManagerImpl.enqueueAction(FragmentManager.java:1338)
at android.support.v4.app.BackStackRecord.commitInternal(BackStackRecord.java:595)
at android.support.v4.app.BackStackRecord.commit(BackStackRecord.java:574)
at android.support.v4.app.FragmentTabHost.onAttachedToWindow(FragmentTabHost.java:278)
at android.view.View.dispatchAttachedToWindow(View.java:12064)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2707)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2714)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2714)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2714)
at android.view.ViewGroup.dispatchAttachedToWindow(ViewGroup.java:2714)
at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1339)
at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1131)
at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:4611)
at android.view.Choreographer$CallbackRecord.run(Choreographer.java:725)
at android.view.Choreographer.doCallbacks(Choreographer.java:555)
at android.view.Choreographer.doFrame(Choreographer.java:525)
at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:711)
at android.os.Handler.handleCallback(Handler.java:615)
at android.os.Handler.dispatchMessage(Handler.java:92)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4898)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:511)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1008)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:775)
at dalvik.system.NativeStart.main(Native Method)

致乔纳森：

我有两个碎片。只有一个片段覆盖onPause回调，代码如下所示。我也不会在onPause之后覆盖其他回调。我覆盖的另一个回调是onResume回调，代码也如下所示。

片段：

@Override
public void onPause() {
    super.onPause();
    if (mView instanceof MyView) {
        MyView my = (MyView) mView;
        my.onPause();
    }
}

@Override
public void onResume() {
    super.onResume();
    if (mView instanceof MyView) {
        MyView my = (MyView) mView;
        my.onResume();
    }
}

MyView:

public void onPause() {
    pause = true;
}

public void onResume() {
    pause = false;
    if (mDialog != null && mDialog.isShowing()) {
        mDialog.dismiss();
        mDialog = null;
    }
}

我还跟踪了FragmentActivity/FragmentManager的代码，如果在onPostResume()之前调用onAttachedToWindow()，那么问题就会发生。是否有可能在onAttachedToWindow()之前调用onPostResume()

Answer 1

此问题是在活动为onPaused后提交片段造成的。

一个简单的解决方案是使用FragmentTransaction.commitAllowingStateLoss()而不是FragmentTransaction.commit()