我正在使用 android JetPack 导航在我的片段之间导航。这就是我的
navigation graph
的样子
<?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/registration_nav_graph"
app:startDestination="@id/registrationStoreNameFragment">
<fragment
android:id="@+id/registrationStoreNameFragment"
android:name="com.minidukaan.android.feature.registration.view.RegistrationStoreNameFragment"
android:label="fragment_registration_store_name"
tools:layout="@layout/fragment_registration_store_name" >
<action
android:id="@+id/action_registrationStoreNameFragment_to_registrationStoreUrlFragment2"
app:destination="@id/registrationStoreUrlFragment2" />
</fragment>
<fragment
android:id="@+id/registrationStoreUrlFragment2"
android:name="com.minidukaan.android.feature.registration.view.RegistrationStoreUrlFragment"
android:label="RegistrationStoreUrlFragment" >
<action
android:id="@+id/action_registrationStoreUrlFragment2_to_registrationLocationFragment"
app:destination="@id/registrationLocationFragment" />
<argument
android:name="store_name"
app:argType="string" />
<argument
android:name="store_slug"
app:argType="string" />
</fragment>
<fragment
android:id="@+id/registrationLocationFragment"
android:name="com.minidukaan.android.feature.registration.view.RegistrationLocationFragment"
android:label="fragment_registration_location"
tools:layout="@layout/fragment_registration_location" >
<action
android:id="@+id/action_registrationLocationFragment_to_registrationSuccessFragment"
app:destination="@id/registrationSuccessFragment" />
<argument
android:name="store_name"
app:argType="string" />
<argument
android:name="store_slug"
app:argType="string"
android:defaultValue=""/>
</fragment>
<fragment
android:id="@+id/registrationSuccessFragment"
android:name="com.minidukaan.android.feature.registration.view.RegistrationSuccessFragment"
android:label="fragment_registration_success"
tools:layout="@layout/fragment_registration_success" />
从
RegistrationStoreNameFragment
我像这样导航到RegistrationStoreUrlFragment
private lateinit var navController: NavController
override fun init(savedInstanceState: Bundle?) {
super.init(savedInstanceState)
....
binding.lifecycleOwner = this
navController = view?.let { Navigation.findNavController(it) }!!
val action = RegistrationStoreNameFragmentDirections.
actionRegistrationStoreNameFragmentToRegistrationStoreUrlFragment2(storeName, it.slug)
navController.navigate(action)
}
所以它可以完美导航,但是当我在
navController.popBackStack()
中执行 RegistrationStoreUrlFragment
时,它不会导航回来。任何帮助将不胜感激,因为我很长时间都陷入这个问题。
对于其他片段,popBackStack 工作正常,但不适用于上面提到的片段。
您想什么时候导航?
如果您想在任何自定义事件中导航回之前添加的片段,
您必须在 NavGraph 中的 Fragment 标签下定义 popUpTo 操作,
<fragment
android:id="@+id/registrationStoreUrlFragment2"
android:name="com.minidukaan.android.feature.registration.view.RegistrationStoreUrlFragment"
android:label="RegistrationStoreUrlFragment" >
<action
android:id="@+id/action_pop_back"
app:destination="@id/registrationSuccessFragment"
app:popUpTo="@+id/registrationSuccessFragment"/>
</fragment>
并在导航中这样调用它,
findNavController().navigate(R.id.action_pop_back)
当前片段要返回 homeFragment
findNavController().popBackStack(R.id.homeFragment, true)
这对我来说工作得很好。也许会对你有帮助
对于我的情况,我遇到了同样的问题,我尝试了通过在
app:popUpTo
中设置 xml
给出的解决方案,但对我来说问题是后退按钮在这种情况下只能工作一次。
然后我用 app:popUpToSaveState
将其设置如下,现在来回工作正常:
<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/anonymous_navigation"
app:startDestination="@id/startupFragment">
<fragment
android:id="@+id/landingFragment"
android:name="com.myApp.ui.landing.LandingFragment"
android:label="fragment_landing"
tools:layout="@layout/fragment_landing" >
<action
android:id="@+id/action_landingFragment_to_loginFragment"
app:destination="@id/loginFragment"
app:popUpToSaveState="@id/landingFragment" />
</fragment>
</navigation>
然后在代码中,当按下后退时我会调用
navigateUp
:
findNavController().navigateUp()