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使用fragmentManager.popbackbackstackimmediate()时出现IllegalStateException;

illegalstateexception fragment android

Cyril David · 技术社区 · 7 年前

创建了一个函数,用于在将新片段设置到容器之前删除存在的所有片段。代码如下:

private static void removeAllFragments(FragmentManager fragmentManager) {
    while (fragmentManager.getBackStackEntryCount() > 0) {
        fragmentManager.popBackStackImmediate();
    }
}

上面的代码在设置片段的函数中调用。代码如下:

public void setupFragment(){
    fragmentManager = getFragmentManager();
    removeAllFragments(Objects.requireNonNull(fragmentManager));
    Log.d(TAG, "setupFragment: getBackStackEntryCount = " + 
    Objects.requireNonNull(fragmentManager).getBackStackEntryCount());
    fragmentTransaction = Objects.requireNonNull(fragmentManager).beginTransaction();
    ApprovalFragment approvalFragment = new ApprovalFragment();
    fragmentTransaction.add(R.id.rel2, approvalFragment);
    fragmentTransaction.addToBackStack("approval");
    fragmentTransaction.commit();
}

打开许多其他应用程序后,一旦此应用程序从内存中退出,则在打开应用程序时会发生崩溃。错误如下:

java.lang.IllegalStateException: FragmentManager is already executing transactions
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2646)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)
    at android.app.ActivityThread.-wrap12(ActivityThread.java)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)
    at android.os.Handler.dispatchMessage(Handler.java:102)
    at android.os.Looper.loop(Looper.java:154)
    at android.app.ActivityThread.main(ActivityThread.java:6077)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
 Caused by: java.lang.IllegalStateException: FragmentManager is already executing transactions
    at android.support.v4.app.FragmentManagerImpl.ensureExecReady(FragmentManager.java:2178)
    at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:2238)
    at android.support.v4.app.FragmentManagerImpl.popBackStackImmediate(FragmentManager.java:836)
    at android.support.v4.app.FragmentManagerImpl.popBackStackImmediate(FragmentManager.java:796)
    at com.example.fragment.HomeFragment.removeAllFragments(HomeFragment.java:650)
    at com.example.fragment.HomeFragment.setupFragment(HomeFragment.java:565)
    at com.example.fragment.HomeFragment.onCreateView(HomeFragment.java:420)
    at android.support.v4.app.Fragment.performCreateView(Fragment.java:2343)
    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1421)
    at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1752)
    at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1821)
    at android.support.v4.app.FragmentManagerImpl.dispatchStateChange(FragmentManager.java:3251)
    at android.support.v4.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManager.java:3205)
    at android.support.v4.app.FragmentController.dispatchActivityCreated(FragmentController.java:195)
    at android.support.v4.app.FragmentActivity.onStart(FragmentActivity.java:597)
    at android.support.v7.app.AppCompatActivity.onStart(AppCompatActivity.java:177)
    at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1249)
    at android.app.Activity.performStart(Activity.java:6722)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2609)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2707)Â 
    at android.app.ActivityThread.-wrap12(ActivityThread.java)Â 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1460)Â 
    at android.os.Handler.dispatchMessage(Handler.java:102)Â 
    at android.os.Looper.loop(Looper.java:154)Â 
    at android.app.ActivityThread.main(ActivityThread.java:6077)Â 
    at java.lang.reflect.Method.invoke(Native Method)Â 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)Â 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)Â

1 回复 | 直到 7 年前

Martin Zeitler 7 年前

你必须使用 .getFragmentChildManager() 而不是 .getFragmentManager() 用一个 android.support.v4.app.Fragment ; 否则你会得到这样的结果 IllegalStateException 扔了。

尚不清楚,如何/在哪里 HomeFragment.removeAllFragments() .addToBackStack() . 该日志缺少的输出 Log.d ,这使得很难理解问题是什么。

使用 .popBackStack() .popBackStackImmediate() 可能也在那里工作。

根据你描述的情况。。。我最好的猜测是 savedInstanceState == null 然后只运行导致崩溃的代码。

Hantash Nadeem 5 年前

发生这种类型的问题是因为从backstack弹出片段后,您会立即将新片段添加到backstack中。