图之间的Android高级导航深层链接

时间：2020-10-27 09:40:40

标签： android android-navigation android-navigation-graph android-deep-link

我已经使用Android Advanced Navigation已有一段时间了。在当前的项目中，我有三个导航图。问题是，一个图中的某些片段应该从另一个图中到达。为了解决这个问题，我进行了深层链接。

例如，在图A中，我包括了图B，然后使用来自图B的深层链接到达该特定片段。问题是当我在图B中并且现在我想跳回图A时我不能。由于图B中未包含图A，因此当前导航控制器无法找到目的地。如果我在图B中包含图A，则会出现另一个问题。 Android Studio无法构建项目，因为它存在循环导入问题（图B试图导入图A，但图B已包含在图A中，等等），我真的不知道该怎么做。

我尝试创建一个包含所有三个子图的巨大导航图，但是我无法使其与此Android Advanced Navigation一起使用。有没有更有效的方法？

编辑以添加代码：

BottomNavigationView扩展名：

fun BottomNavigationView.setupWithNavController(
    navGraphIds: List<Int>,
    fragmentManager: FragmentManager,
    containerId: Int,
    intent: Intent
): LiveData<NavController> {

    // Map of tags
    val graphIdToTagMap = SparseArray<String>()
    // Result. Mutable live data with the selected controlled
    val selectedNavController = MutableLiveData<NavController>()

    var firstFragmentGraphId = 0

    // First create a NavHostFragment for each NavGraph ID
    navGraphIds.forEachIndexed { index, navGraphId ->
        val fragmentTag = getFragmentTag(index)

        // Find or create the Navigation host fragment
        val navHostFragment = obtainNavHostFragment(
            fragmentManager,
            fragmentTag,
            navGraphId,
            containerId
        )

        // Obtain its id
        val graphId = navHostFragment.navController.graph.id

        if (index == 0) {
            firstFragmentGraphId = graphId
        }

        // Save to the map
        graphIdToTagMap[graphId] = fragmentTag

        // Attach or detach nav host fragment depending on whether it's the selected item.
        if (this.selectedItemId == graphId) {
            // Update livedata with the selected graph
            selectedNavController.value = navHostFragment.navController
            attachNavHostFragment(fragmentManager, navHostFragment, index == 0)
        } else {
            detachNavHostFragment(fragmentManager, navHostFragment)
        }
    }

    // Now connect selecting an item with swapping Fragments
    var selectedItemTag = graphIdToTagMap[this.selectedItemId]
    val firstFragmentTag = graphIdToTagMap[firstFragmentGraphId]
    var isOnFirstFragment = selectedItemTag == firstFragmentTag

    // When a navigation item is selected
    setOnNavigationItemSelectedListener { item ->
        // Don't do anything if the state is state has already been saved.
        if (fragmentManager.isStateSaved) {
            false
        } else {
            val newlySelectedItemTag = graphIdToTagMap[item.itemId]
            if (selectedItemTag != newlySelectedItemTag) {
                // Pop everything above the first fragment (the "fixed start destination")
                fragmentManager.popBackStack(firstFragmentTag,
                    FragmentManager.POP_BACK_STACK_INCLUSIVE)
                val selectedFragment = fragmentManager.findFragmentByTag(newlySelectedItemTag)
                        as NavHostFragment

                // Exclude the first fragment tag because it's always in the back stack.
                if (firstFragmentTag != newlySelectedItemTag) {
                    // Commit a transaction that cleans the back stack and adds the first fragment
                    // to it, creating the fixed started destination.
                    fragmentManager.beginTransaction()
                        .setCustomAnimations(
                            R.anim.nav_default_enter_anim,
                            R.anim.nav_default_exit_anim,
                            R.anim.nav_default_pop_enter_anim,
                            R.anim.nav_default_pop_exit_anim)
                        .attach(selectedFragment)
                        .setPrimaryNavigationFragment(selectedFragment)
                        .apply {
                            // Detach all other Fragments
                            graphIdToTagMap.forEach { _, fragmentTagIter ->
                                if (fragmentTagIter != newlySelectedItemTag) {
                                    detach(fragmentManager.findFragmentByTag(firstFragmentTag)!!)
                                }
                            }
                        }
                        .addToBackStack(firstFragmentTag)
                        .setReorderingAllowed(true)
                        .commit()
                }
                selectedItemTag = newlySelectedItemTag
                isOnFirstFragment = selectedItemTag == firstFragmentTag
                selectedNavController.value = selectedFragment.navController
                true
            } else {
                false
            }
        }
    }

    // Optional: on item reselected, pop back stack to the destination of the graph
    setupItemReselected(graphIdToTagMap, fragmentManager)

    // Handle deep link
    setupDeepLinks(navGraphIds, fragmentManager, containerId, intent)

    // Finally, ensure that we update our BottomNavigationView when the back stack changes
    fragmentManager.addOnBackStackChangedListener {
        if (!isOnFirstFragment && !fragmentManager.isOnBackStack(firstFragmentTag)) {
            this.selectedItemId = firstFragmentGraphId
        }

        // Reset the graph if the currentDestination is not valid (happens when the back
        // stack is popped after using the back button).
        selectedNavController.value?.let { controller ->
            if (controller.currentDestination == null) {
                controller.navigate(controller.graph.id)
            }
        }
    }
    return selectedNavController
}

private fun BottomNavigationView.setupDeepLinks(
    navGraphIds: List<Int>,
    fragmentManager: FragmentManager,
    containerId: Int,
    intent: Intent
) {
    navGraphIds.forEachIndexed { index, navGraphId ->
        val fragmentTag = getFragmentTag(index)

        // Find or create the Navigation host fragment
        val navHostFragment = obtainNavHostFragment(
            fragmentManager,
            fragmentTag,
            navGraphId,
            containerId
        )
        // Handle Intent
        if (navHostFragment.navController.handleDeepLink(intent)
            && selectedItemId != navHostFragment.navController.graph.id) {
            this.selectedItemId = navHostFragment.navController.graph.id
        }
    }
}

private fun BottomNavigationView.setupItemReselected(
    graphIdToTagMap: SparseArray<String>,
    fragmentManager: FragmentManager
) {
    setOnNavigationItemReselectedListener { item ->
        val newlySelectedItemTag = graphIdToTagMap[item.itemId]
        val selectedFragment = fragmentManager.findFragmentByTag(newlySelectedItemTag)
                as NavHostFragment
        val navController = selectedFragment.navController
        // Pop the back stack to the start destination of the current navController graph
        navController.popBackStack(
            navController.graph.startDestination, false
        )
    }
}

private fun detachNavHostFragment(
    fragmentManager: FragmentManager,
    navHostFragment: NavHostFragment
) {
    fragmentManager.beginTransaction()
        .detach(navHostFragment)
        .commitNow()
}

private fun attachNavHostFragment(
    fragmentManager: FragmentManager,
    navHostFragment: NavHostFragment,
    isPrimaryNavFragment: Boolean
) {
    fragmentManager.beginTransaction()
        .attach(navHostFragment)
        .apply {
            if (isPrimaryNavFragment) {
                setPrimaryNavigationFragment(navHostFragment)
            }
        }
        .commitNow()

}

private fun obtainNavHostFragment(
    fragmentManager: FragmentManager,
    fragmentTag: String,
    navGraphId: Int,
    containerId: Int
): NavHostFragment {
    // If the Nav Host fragment exists, return it
    val existingFragment = fragmentManager.findFragmentByTag(fragmentTag) as NavHostFragment?
    existingFragment?.let { return it }

    // Otherwise, create it and return it.
    val navHostFragment = NavHostFragment.create(navGraphId)
    fragmentManager.beginTransaction()
        .add(containerId, navHostFragment, fragmentTag)
        .commitNow()
    return navHostFragment
}

private fun FragmentManager.isOnBackStack(backStackName: String): Boolean {
    val backStackCount = backStackEntryCount
    for (index in 0 until backStackCount) {
        if (getBackStackEntryAt(index).name == backStackName) {
            return true
        }
    }
    return false
}

private fun getFragmentTag(index: Int) = "bottomNavigation#$index"

导航图：

<?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/home_nav_graph"
    app:startDestination="@id/homeFragment">

    <fragment
        android:id="@+id/homeFragment"
        android:name="lu.thebiggame.fragments.home.HomeFragment"
        android:label="home_fragment"
        tools:layout="@layout/home_fragment" >
        <action
            android:id="@+id/homeToGameResults"
            app:destination="@id/gameResultsFragment" />
        <action
            android:id="@+id/homeToPlayLottoGames"
            app:destination="@id/playLottoGamesFragment" />
    </fragment>
    <fragment
        android:id="@+id/checkoutFragment"
        tools:layout="@layout/checkout_fragment"
        android:name="lu.thebiggame.fragments.checkout.CheckoutFragment"
        android:label="CheckoutFragment" />
    <fragment
        android:id="@+id/gameResultsFragment"
        android:name="lu.thebiggame.fragments.gameresults.GameResultsFragment"
        android:label="game_results_fragment"
        tools:layout="@layout/game_results_fragment">
        <deepLink
            android:id="@+id/gameResultsFragmentDeepLink"
            app:uri="app://home/game-results-fragment" />
        <action
            android:id="@+id/gameResultsToPlayLottoGames"
            app:destination="@id/playLottoGamesFragment" />
    </fragment>
    <fragment
        android:id="@+id/congratulationsFragment"
        android:name="lu.thebiggame.fragments.congratulations.CongratulationsFragment"
        android:label="congratulations_fragment"
        tools:layout="@layout/congratulations_fragment" >
        <action
            android:id="@+id/congratulationsToClaim"
            app:destination="@id/claimFragment" />
        <deepLink
            android:id="@+id/congratulationsFragmentDeepLink"
            app:uri="app://home/congratulations-fragment" />
    </fragment>
    <fragment
        android:id="@+id/claimFragment"
        tools:layout="@layout/claim_fragment"
        android:name="lu.thebiggame.fragments.claim.ClaimFragment"
        android:label="ClaimFragment" />

    <include app:graph="@navigation/profile_nav_graph"/>
    <fragment
        android:id="@+id/aboutGameFragment"
        android:name="lu.thebiggame.fragments.page.PageFragment"
        android:label="page_fragment"
        tools:layout="@layout/page_fragment">

        <deepLink
            android:id="@+id/aboutGameFragmentDeepLink"
            app:uri="app://home/about-game-fragment" />
    </fragment>
    <fragment
        android:id="@+id/playLottoGamesFragment"
        android:name="lu.thebiggame.fragments.play.lottogames.PlayLottoGamesFragment"
        tools:layout="@layout/play_lotto_games_fragment"
        android:label="PlayLottoGamesFragment" >
        <action
            android:id="@+id/playLottoGamesToCheckout"
            app:destination="@id/checkoutFragment" />
        <deepLink
            android:id="@+id/playLottoGamesDeepLink"
            app:uri="app://home/play-lotto-games-fragment" />
        <action
            android:id="@+id/playLottoGamesToGameResults"
            app:destination="@id/gameResultsFragment" />
    </fragment>

</navigation>

<?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/games_nav_graph"
    app:startDestination="@id/gamesFragment">

    <fragment
        android:id="@+id/gamesFragment"
        android:name="lu.thebiggame.fragments.games.GamesFragment"
        android:label="games_fragment"
        tools:layout="@layout/games_fragment" />

    <include app:graph="@navigation/home_nav_graph"/>
</navigation>

<?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/profile_nav_graph"
    app:startDestination="@id/profileFragment">

    <fragment
        android:id="@+id/profileFragment"
        android:name="lu.thebiggame.fragments.profile.ProfileFragment"
        android:label="profile_fragment"
        tools:layout="@layout/profile_fragment" >
        <action
            android:id="@+id/profileToResults"
            app:destination="@id/resultsFragment" />
        <action
            android:id="@+id/profileToHelp"
            app:destination="@id/helpFragment" />
        <action
            android:id="@+id/profileToPersonal"
            app:destination="@id/personalFragment" />
        <action
            android:id="@+id/profileToChangePassword"
            app:destination="@id/changePasswordFragment" />
        <action
            android:id="@+id/profileToPage"
            app:destination="@id/pageFragment" />
    </fragment>
    <fragment
        android:id="@+id/resultsFragment"
        android:name="lu.thebiggame.fragments.results.ResultsFragment"
        android:label="results_fragment"
        tools:layout="@layout/results_fragment" >
        <argument
            android:name="startingTab"
            app:argType="integer"
            android:defaultValue="0" />
        <deepLink
            android:id="@+id/resultsFragmentDeepLink"
            android:autoVerify="true"
            app:uri="app://profile/results-fragment" />
        <action
            android:id="@+id/resultsToClaim"
            app:destination="@id/claimFragmentResults" />
    </fragment>
    <fragment
        android:id="@+id/helpFragment"
        android:name="lu.thebiggame.fragments.help.HelpFragment"
        android:label="help_fragment"
        tools:layout="@layout/help_fragment" >
        <action
            android:id="@+id/helpToPage"
            app:destination="@id/pageFragment" />
        <action
            android:id="@+id/helpToContact"
            app:destination="@id/contactUsFragment" />
        <action
            android:id="@+id/helpToFaq"
            app:destination="@id/faqFragment" />
    </fragment>
    <fragment
        android:id="@+id/personalFragment"
        android:name="lu.thebiggame.fragments.personal.PersonalFragment"
        android:label="personal_fragment"
        tools:layout="@layout/personal_fragment" />
    <fragment
        android:id="@+id/changePasswordFragment"
        android:name="lu.thebiggame.fragments.changepassword.ChangePasswordFragment"
        android:label="change_password_fragment"
        tools:layout="@layout/change_password_fragment" />
    <fragment
        android:id="@+id/pageFragment"
        android:name="lu.thebiggame.fragments.page.PageFragment"
        android:label="page_fragment"
        tools:layout="@layout/page_fragment" />
    <fragment
        android:id="@+id/contactUsFragment"
        android:name="lu.thebiggame.fragments.contactus.ContactUsFragment"
        android:label="contact_us_fragment"
        tools:layout="@layout/contact_us_fragment" />
    <fragment
        android:id="@+id/faqFragment"
        android:name="lu.thebiggame.fragments.faqfragment.FaqFragment"
        android:label="faq_fragment"
        tools:layout="@layout/faq_fragment" />
    <fragment
        android:id="@+id/claimFragmentResults"
        tools:layout="@layout/claim_fragment"
        android:name="lu.thebiggame.fragments.claim.ClaimFragment"
        android:label="ClaimFragment" />


</navigation>

初始化底部导航：

    private fun setupBottomNavigationBar() {

        activityMainBottomNav.itemIconTintList = null

        val navGraphIds = listOf(
            R.navigation.home_nav_graph,
            R.navigation.games_nav_graph,
            R.navigation.profile_nav_graph
        )

        val controller = activityMainBottomNav.setupWithNavController(
            navGraphIds = navGraphIds,
            fragmentManager = supportFragmentManager,
            containerId = R.id.nav_host_container,
            intent = intent
        )

        currentNavController = controller
    }

1 个答案:

答案 0 :(得分：0)

由于没有人愿意回答我，这就是我所做的。我可以将所有三个导航图中出现的所有片段都移到另一个图中，并将其命名为共享图。此外，为了导航到该图，我为其创建了标准动作，但是在导航之前，请确保更改共享图的起始位置。

    fun navigateToNestedGraph(navDir: NavDirections, destination: Int, navOps: NavOptions? = null){
        val view = (this as Fragment).requireView()
        val navController = Navigation.findNavController(view)
        val graph = navController.graph.findNode(R.id.shared_nav_graph)
        if (graph is NavGraph){
            graph.startDestination = destination
            navController.navigate(navDir, navOps)
        }
    }

这是我的Fragments实现的来自侦听器的函数。就是这样。

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