我正在尝试添加 test navigation conditional navigation 文档中的示例.
我按照示例创建了一个演示并将其发布在 github 上.
演示包含 3 个 fragment :HomeFragment
, ProfileFragment
和 LoginFragment
.在ProfileFragment
有条件检查用户是否已连接。如果用户未连接,他将被发送到 LoginFragment
.
个人资料 fragment
@AndroidEntryPoint
class ProfileFragment : Fragment(R.layout.fragment_profile) {
private val mainViewModel: MainViewModel by activityViewModels()
private val navController by lazy { findNavController() }
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
val currentBackStackEntry = navController.currentBackStackEntry!!
currentBackStackEntry.savedStateHandle.getLiveData<Boolean>(LoginFragment.LOGIN_SUCCESSFUL)
.observe(currentBackStackEntry, { success ->
if (!success) {
val startDestination = navController.graph.startDestination
val navOptions = NavOptions.Builder()
.setPopUpTo(startDestination, true)
.build()
navController.navigate(startDestination, null, navOptions)
}
})
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
mainViewModel.user.observe(viewLifecycleOwner, {
if(!it){
navController.navigate(R.id.loginFragment)
}
})
}
}
如文档中所述,在 onCreate()
中方法我正在观察 LOGIN_SUCCESSFUL
值存储在 SavedStateHandle
中以便在用户未登录时重定向用户。
登录 fragment
@AndroidEntryPoint
class LoginFragment : Fragment() {
companion object {
const val LOGIN_SUCCESSFUL: String = "LOGIN_SUCCESSFUL"
}
private val viewModel: LoginViewModel by viewModels()
private val navController by lazy { findNavController() }
private lateinit var savedStateHandle: SavedStateHandle
private lateinit var binding: FragmentLoginBinding
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View {
binding = DataBindingUtil.inflate(inflater, R.layout.fragment_login, container, false)
binding.viewModel = viewModel
binding.lifecycleOwner = this
return binding.root
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
savedStateHandle = navController.previousBackStackEntry!!.savedStateHandle
savedStateHandle.set(LOGIN_SUCCESSFUL, false)
viewModel.login.observe(viewLifecycleOwner, ResultObserver {
if (it.status == Status.ERROR) {
Snackbar.make(requireView(), it.message ?: "Error", Snackbar.LENGTH_SHORT).show()
} else if (it.status == Status.SUCCESS) {
savedStateHandle.set(LOGIN_SUCCESSFUL, true)
navController.popBackStack()
}
})
}
}
测试
@Test
fun profileFragment_unauthenticated() {
setAuthentication(false)
val navController = TestNavHostController(ApplicationProvider.getApplicationContext())
launchFragmentInHiltContainer<ProfileFragment> {
navController.setViewModelStore(ViewModelStore())
navController.setGraph(R.navigation.nav_main)
navController.setCurrentDestination(R.id.profileFragment)
Navigation.setViewNavController(requireView(), navController)
}
assertEquals(navController.currentDestination?.id, R.id.loginFragment)
}
因为我使用 Hilt 进行依赖项注入(inject),所以我需要将 fragment 附加到用 @AndroidEntryPoint
注释的 Activity 中: launchFragmentInHiltContainer
在测试期间,我正在创建 TestNavHostController
的实例并将其分配给 fragment 。
问题是我正在访问 navController
在onCreate
navController
的方法在 RESUMED
期间实例化状态(参见 FragmentScenario)。导致 java.lang.IllegalStateException: Fragment ProfileFragment ... does not have a NavController set
我知道可以制作 navController
通过向 fragment 的 viewLifecycleOwnerLiveData
添加观察者可以更快地使用.然而,这还不够快。
那么,这种情况下如何实现测试导航呢?
可能的解决方案
在寻找向我的 fragment 添加测试的方法几天后,我认为我找到了解决方案。这个想法是附上 navController
到 Activity 。但是,我对结果并不完全满意,这就是为什么我没有将此解决方案作为答案发布的原因。对于任何感兴趣的人,我将我的解决方案添加到 github repository .
最佳答案
I know it's possible to make the navController available sooner by adding an observer to the fragment's viewLifecycleOwnerLiveData. However, it is not soon enough.
其实你用错了。
正如这里提到的谷歌文档 https://developer.android.com/guide/navigation/navigation-testing#test_navigationui_with_fragmentscenario
他们使用具有 FragmentFactory 的 launchFragmentInContainer 来控制 Fragment 的实例化实例。
这就是您使用 activity.supportFragmentManager.fragmentFactory
创建 fragment 的方式
val fragment: Fragment = activity.supportFragmentManager.fragmentFactory.instantiate(
Preconditions.checkNotNull(T::class.java.classLoader),
T::class.java.name
)
将 activity.supportFragmentManager.fragmentFactory
替换为
val fragmentFactory = object : FragmentFactory() {
override fun instantiate(
classLoader: ClassLoader,
className: String
) = when (className) {
T::class.java.name -> action()
else -> super.instantiate(classLoader, className)
}
}
所以你会像这样创建 fragment
val fragment: Fragment = fragmentFactory.instantiate(
Preconditions.checkNotNull(T::class.java.classLoader),
T::class.java.name
)
替换 crossinline Action :Activity.() -> Unit = {}
使用 crossinline Action :() -> T
删除 activity.action()
因为它已经在 FragmentFactory 中使用了,正如您在上面看到的那样
所以
launchFragmentInHiltContainer()
看起来像这样
inline fun <reified T : Fragment> launchFragmentInHiltContainer(
fragmentArgs: Bundle? = null,
@StyleRes themeResId: Int = R.style.FragmentScenarioEmptyFragmentActivityTheme,
crossinline action: () -> T) {
val startActivityIntent = Intent.makeMainActivity(
ComponentName(
ApplicationProvider.getApplicationContext(),
HiltTestActivity::class.java
)
).putExtra(
"androidx.fragment.app.testing.FragmentScenario.EmptyFragmentActivity.THEME_EXTRAS_BUNDLE_KEY",
themeResId
)
ActivityScenario.launch<HiltTestActivity>(startActivityIntent).onActivity { activity ->
val fragmentFactory = object : FragmentFactory() {
override fun instantiate(
classLoader: ClassLoader,
className: String
) = when (className) {
T::class.java.name -> action()
else -> super.instantiate(classLoader, className)
}
}
val fragment: Fragment = fragmentFactory.instantiate(
Preconditions.checkNotNull(T::class.java.classLoader),
T::class.java.name
)
fragment.arguments = fragmentArgs
activity.supportFragmentManager
.beginTransaction()
.add(android.R.id.content, fragment, "")
.commitNow()
} }
现在您可以使用 google here 提供的相同代码和 hilt 注入(inject),如下所示
launchFragmentInHiltContainer {
ProfileFragment().also { fragment ->
fragment.viewLifecycleOwnerLiveData.observeForever { viewLifecycleOwner ->
if (viewLifecycleOwner != null) {
navController.setViewModelStore(ViewModelStore())
navController.setGraph(R.navigation.nav_main)
navController.setCurrentDestination(R.id.profileFragment)
Navigation.setViewNavController(requireView(), navController)
}
}
}
}
关于android - 如何使用条件导航将 androidTest 添加到 fragment ?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/67830592/