片段不与片段管理器关联答案

【问题标题】：Fragment Not Associated With A Fragment Manager片段不与片段管理器关联
【发布时间】：2019-04-11 11:50:21
【问题描述】：

我正在使用Navigation Component 为具有一个活动和多个片段的应用编写一些插桩测试。

我的启动画面代码如下：

class SplashFragment : Fragment(), KodeinAware {

    override val kodein by Admin.instance.kodein

    private var realm: Realm? = null

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
        return inflater.inflate(R.layout.splash, container, false)
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)

        (activity as? AppCompatActivity)?.supportActionBar?.hide()

        realm = Realm.getInstance(RealmUtil.realmConfig)

        val result = realm!!.where<User>().findFirst()
        val user = if (result != null) realm!!.copyFromRealm(result) else null

        Handler().postDelayed({
            if (user == null)
                findNavController().navigate(R.id.action_splashFragment_to_loginFragment) //navigate to login screen if no user exists
            else
                findNavController().navigate(R.id.action_splashFragment_to_businessListFragment) //navigate to business list if user already logged in
        }, 2000)
    }

    override fun onDestroy() {
        super.onDestroy()

        realm?.close()
    }
}

我正在尝试测试启动屏幕之后出现的片段，但我不断收到以下错误：

java.lang.IllegalStateException: Fragment SplashFragment{a1ca381 (5f5b98ae-c130-4e9b-9b77-0495561ef4f5)} not associated with a fragment manager.
at androidx.fragment.app.Fragment.requireFragmentManager(Fragment.java:891)
at androidx.navigation.fragment.NavHostFragment.findNavController(NavHostFragment.java:106)
at androidx.navigation.fragment.FragmentKt.findNavController(Fragment.kt:29)
at com.chargebot.collect.admin.fragment.onboarding.SplashFragment$onViewCreated$1.run(SplashFragment.kt:44)
at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
at androidx.test.espresso.base.Interrogator.loopAndInterrogate(Interrogator.java:148)
at androidx.test.espresso.base.UiControllerImpl.loopUntil(UiControllerImpl.java:519)
at androidx.test.espresso.base.UiControllerImpl.loopUntil(UiControllerImpl.java:478)
at androidx.test.espresso.base.UiControllerImpl.injectKeyEvent(UiControllerImpl.java:201)
at androidx.test.espresso.base.UiControllerImpl.injectString(UiControllerImpl.java:357)
at androidx.test.espresso.action.TypeTextAction.perform(TypeTextAction.java:108)
at androidx.test.espresso.ViewInteraction$SingleExecutionViewAction.perform(ViewInteraction.java:360)
at androidx.test.espresso.ViewInteraction.doPerform(ViewInteraction.java:251)
at androidx.test.espresso.ViewInteraction.access$100(ViewInteraction.java:64)
at androidx.test.espresso.ViewInteraction$1.call(ViewInteraction.java:157)
at androidx.test.espresso.ViewInteraction$1.call(ViewInteraction.java:154)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)

我的测试类如下：

@RunWith(AndroidJUnit4::class)
@MediumTest
class SignInTest {

    @get: Rule
    val login = ActivityScenarioRule(Home::class.java)

    @Test
    fun loginWithoutEmail_ShouldDisplayError() {
        val scenario = launchFragmentInContainer<LoginFragment>()

        onView(withId(R.id.password)).perform(typeText("samplePassword"), closeSoftKeyboard())
        onView(withId(R.id.login)).perform(click())

        onView(withId(com.google.android.material.R.id.snackbar_text)).check(matches(withText(R.string.enter_email)))
    }

    @Test
    fun loginWithoutPassword_ShouldDisplayError() {
        val scenario = launchFragmentInContainer<LoginFragment>()

        onView(withId(R.id.email)).perform(typeText("sample@password.com"), closeSoftKeyboard())
        onView(withId(R.id.login)).perform(click())

        onView(withId(com.google.android.material.R.id.snackbar_text)).check(matches(withText(R.string.enter_password)))
    }
}

由于上述错误，我的任何测试功能都不会执行。由于我在启动画面上运行的测试成功运行，导致异常的原因是什么？

我的nav_graph如下：

<?xml version="1.0" encoding="utf-8"?>
<navigation xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/nav_graph"
    app:startDestination="@id/splashFragment">

    <fragment
        android:id="@+id/splashFragment"
        android:name="com.chargebot.collect.admin.fragment.onboarding.SplashFragment"
        android:label="SplashFragment"
        tools:layout="@layout/splash">
        <action
            android:id="@+id/action_splashFragment_to_loginFragment"
            app:destination="@id/loginFragment"
            app:popUpTo="@+id/splashFragment"
            app:popUpToInclusive="true" />
        <action
            android:id="@+id/action_splashFragment_to_businessListFragment"
            app:destination="@id/businessListFragment"
            app:popUpTo="@+id/splashFragment"
            app:popUpToInclusive="true" />
    </fragment>
    <fragment
        android:id="@+id/registrationFragment"
        android:name="com.chargebot.collect.admin.fragment.onboarding.RegistrationFragment"
        android:label="RegistrationFragment"
        tools:layout="@layout/registration">
        <action
            android:id="@+id/action_registrationFragment_to_businessListFragment"
            app:destination="@id/businessListFragment"
            app:popUpTo="@+id/registrationFragment"
            app:popUpToInclusive="true" />
        <action
            android:id="@+id/action_registrationFragment_to_loginFragment"
            app:destination="@id/loginFragment"
            app:popUpTo="@+id/registrationFragment"
            app:popUpToInclusive="true" />
    </fragment>
    <fragment
        android:id="@+id/loginFragment"
        android:name="com.chargebot.collect.admin.fragment.onboarding.LoginFragment"
        android:label="LoginFragment"
        tools:layout="@layout/login">
        <action
            android:id="@+id/action_loginFragment_to_businessListFragment"
            app:destination="@id/businessListFragment"
            app:popUpTo="@+id/loginFragment"
            app:popUpToInclusive="true" />
        <action
            android:id="@+id/action_loginFragment_to_registrationFragment"
            app:destination="@id/registrationFragment"
            app:popUpTo="@+id/loginFragment"
            app:popUpToInclusive="true" />
    </fragment>
    <fragment
        android:id="@+id/businessListFragment"
        android:name="com.chargebot.collect.admin.fragment.business.BusinessListFragment"
        android:label="BusinessListFragment"
        tools:layout="@layout/businesses_list">
        <action
            android:id="@+id/action_businessListFragment_to_newBusinessFragment"
            app:destination="@id/newBusinessFragment" />
        <action
            android:id="@+id/action_businessListFragment_to_branchesFragment"
            app:destination="@id/branchesFragment" />
    </fragment>
    <fragment
        android:id="@+id/newBusinessFragment"
        android:name="com.chargebot.collect.admin.fragment.business.NewBusinessFragment"
        android:label="NewBusinessFragment"
        tools:layout="@layout/add_business_layout">
        <action
            android:id="@+id/action_newBusinessFragment_to_businessListFragment"
            app:destination="@id/businessListFragment" />
    </fragment>
    <fragment
        android:id="@+id/branchesFragment"
        android:name="com.chargebot.collect.admin.fragment.branch.BranchesFragment"
        android:label="BranchesFragment"
        tools:layout="@layout/branches_layout">
        <action
            android:id="@+id/action_branchesFragment_to_transactionsFragment"
            app:destination="@id/transactionsFragment" />
        <action
            android:id="@+id/action_branchesFragment_to_newBranchFragment"
            app:destination="@id/newBranchFragment" />
        <action
            android:id="@+id/action_branchesFragment_to_collectorsFragment"
            app:destination="@id/collectorsFragment" />
    </fragment>
    <fragment
        android:id="@+id/transactionsFragment"
        android:name="com.chargebot.collect.admin.fragment.transactions.TransactionsFragment"
        android:label="TransactionsFragment"
        tools:layout="@layout/transactions" />
    <fragment
        android:id="@+id/newBranchFragment"
        android:name="com.chargebot.collect.admin.fragment.branch.NewBranchFragment"
        android:label="NewBranchFragment"
        tools:layout="@layout/add_branch_layout" />
    <fragment
        android:id="@+id/collectorsFragment"
        android:name="com.chargebot.collect.admin.fragment.collector.CollectorsFragment"
        android:label="CollectorsFragment"
        tools:layout="@layout/client_list_layout">
        <action
            android:id="@+id/action_collectorsFragment_to_newCollectorFragment"
            app:destination="@id/newCollectorFragment" />
        <action
            android:id="@+id/action_collectorsFragment_to_transactionsFragment"
            app:destination="@id/transactionsFragment" />
        <action
            android:id="@+id/action_collectorsFragment_to_collectorTransactions"
            app:destination="@id/collectorTransactions" />
    </fragment>
    <fragment
        android:id="@+id/newCollectorFragment"
        android:name="com.chargebot.collect.admin.fragment.collector.NewCollectorFragment"
        android:label="NewCollectorFragment"
        tools:layout="@layout/new_client_layout" />
    <fragment
        android:id="@+id/collectorTransactions"
        android:name="com.chargebot.collect.admin.fragment.transactions.CollectorTransactionsFragment"
        android:label="CollectorTransactions"
        tools:layout="@layout/transaction_layout">
        <action
            android:id="@+id/action_collectorTransactions_to_collectorsFragment"
            app:destination="@id/collectorsFragment"
            app:popUpTo="@id/collectorsFragment" />
    </fragment>

</navigation>

【问题讨论】：

你能发布 nav_graph xml 吗？
@Moinkhan 请通过nav_graph查看更新的问题
您是否将项目从 appcompat 迁移到 androidx ？如果是这种情况，请将 appcompat 的片段管理器更改为 android x。
评论后能否重新运行测试用例 Handler().postDelayed({ if (user == null) findNavController().navigate(R.id.action_splashFragment_to_loginFragment) //navigate to login screen if no user exists else findNavController().navigate(R.id.action_splashFragment_to_businessListFragment) //navigate to business list if user already logged in }, 2000)
@rajkavadia 是的，我正在使用AndroidX。但是，使用Navigation Component 意味着我不需要使用FragmentManager。

标签： android android-fragments android-espresso android-architecture-navigation instrumented-test

【解决方案1】：

我发现在我的情况下，问题与线程有关。我解决了它：

 lifecycleScope.launchWhenResumed {
      findNavController().navigate(R.id.action_splashFragment_to_loginFragment)
 }

很高兴知道这是否对您有帮助？！

【讨论】：

是的，这对我有帮助，而且看起来比 postDelayed 更简洁。
太完美了。完美的胜利，我的朋友。

【解决方案2】：

在你的代码下方评论

Handler().postDelayed({ 
   if (user == null) 
      findNavController().navigate(R.id.action_splashFragment_to_loginFragment) 
      //navigate to login screen if no user exists 
   else
      findNavController().navigate(R.id.action_splashFragment_to_businessListFragment) 
      //navigate to business list if user already logged in 
}, 2000)

如果效果好的话

使用Thread.sleep(5000) 或IdlingResource 延迟您的仪器测试用例。

根本原因： 实际上，在您的测试用例运行时，您正在尝试对等待 Handler 执行 2000 毫秒的片段进行操作。

【讨论】：

我认为你的假设是错误的。当我尝试在 corotuineScope 中等待 2 秒然后 findNavContoller.navigate 某处时，我的 NavController 失败并出现相同的错误：“Fragment Not Associated With A Fragment Manager”
我的意思是，我等待，然后检查我是否还在那个片段上，然后才导航

【解决方案3】：

我刚刚在测试中发现了这个问题

通过关注navigation test documentation，我能够解决使用 navController 为片段创建场景的问题

val scenario = launchFragmentInContainer {
    TitleScreen().also { fragment ->

        // In addition to returning a new instance of our Fragment,
        // get a callback whenever the fragment’s view is created
        // or destroyed so that we can set the NavController
        fragment.viewLifecycleOwnerLiveData.observeForever { viewLifecycleOwner ->
            if (viewLifecycleOwner != null) {
                // The fragment’s view has just been created
                navController.setGraph(R.navigation.trivia)
                Navigation.setViewNavController(fragment.requireView(), navController)
            }
        }
    }
}

【讨论】：

【解决方案4】：

我正在使用这样的代码希望这能解决问题

Handler(Looper.getMainLooper()).postDelayed({ //你的代码

}, 2000)

【讨论】：

【解决方案5】：

此链接很有帮助... https://www.py4u.net/discuss/667013

我创建了监听器并添加到导航中

findNavController().addOnDestinationChangedListener(listenerNavigation)

但没有删除它。由于它不是生命周期感知的，因此即使在片段被销毁后它也有对片段的引用。因此，在 Ramkrishna Joshi 对此链接的回答的帮助下，我删除了 onDestroyView() 中的侦听器

findNavController().removeOnDestinationChangedListener(listenerNavigation)

错误消失了。

如果您在片段或活动中使用生命周期不知情的侦听器，请在适当的位置手动销毁它们。

【讨论】：