android - 带有架构导航组件的底部导航 fragment 的动画

Question

我已经成功地将底部导航与最新的android架构导航组件集成在一起。以下是我的完整代码。

导航

<?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/mobile_navigation"
    app:startDestination="@+id/navigation_home">

    <fragment
        android:id="@+id/navigation_home"
        android:name="in.zedone.bottomsample.ui.home.HomeFragment"
        android:label="@string/title_home"
        tools:layout="@layout/fragment_home" />

    <fragment
        android:id="@+id/navigation_saloons"
        android:name="in.zedone.bottomsample.ui.saloons.SaloonsFragment"
        android:label="@string/title_saloon"
        tools:layout="@layout/fragment_saloons" />

    <fragment
        android:id="@+id/navigation_offers"
        android:name="in.zedone.bottomsample.ui.offers.OffersFragment"
        android:label="@string/title_offer"
        tools:layout="@layout/fragment_offers" />

    <fragment
        android:id="@+id/navigation_account"
        android:name="in.zedone.bottomsample.ui.account.AccountFragment"
        android:label="@string/title_account"
        tools:layout="@layout/fragment_account" />

</navigation>

底部导航查看

<com.google.android.material.bottomnavigation.BottomNavigationView
     android:id="@+id/nav_view"
     android:layout_width="0dp"
     android:layout_height="wrap_content"
     android:layout_marginStart="0dp"
     android:layout_marginEnd="0dp"
     android:background="?android:attr/windowBackground"
     app:labelVisibilityMode="labeled"
     app:itemTextAppearanceActive="@style/BottomNavigationView.Active"
     app:itemTextAppearanceInactive="@style/BottomNavigationView"
     app:layout_constraintBottom_toBottomOf="parent"
     app:layout_constraintLeft_toLeftOf="parent"
     app:layout_constraintRight_toRightOf="parent"
     app:menu="@menu/bottom_nav_menu" />

主要 Activity

BottomNavigationView navView = findViewById(R.id.nav_view);
// Passing each menu ID as a set of Ids because each
// menu should be considered as top level destinations.
AppBarConfiguration appBarConfiguration = new AppBarConfiguration.Builder(
                R.id.navigation_home, R.id.navigation_saloons, R.id.navigation_offers,R.id.navigation_account)
                .build();
NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment);
NavigationUI.setupActionBarWithNavController(this, navController, appBarConfiguration);
NavigationUI.setupWithNavController(navView, navController);

现在如何在底部导航中选择每个选项卡/fragment 时添加过渡/动画？

Answer 1

不要使用 setupWithNavController 函数，而是按照这种方式。
首先，创建包含如下所示动画的 NavOptions。

val options = NavOptions.Builder()
            .setLaunchSingleTop(true)
            .setEnterAnim(R.anim.enter_from_bottom)
            .setExitAnim(R.anim.exit_to_top)
            .setPopEnterAnim(R.anim.enter_from_top)
            .setPopExitAnim(R.anim.exit_to_bottom)
            .setPopUpTo(navController.graph.startDestination, false)
            .build()

然后使用 setOnNavigationItemSelectedListener 来导航这样的动画。

bottomNavigationView.setOnNavigationItemSelectedListener { item ->
        when(item.itemId) {
            R.id.fragmentFirst -> {
                navController.navigate(R.id.fragmentFirst,null,options)
            }
            R.id.fragmentSecond -> {
                navController.navigate(R.id.fragmentSecond,null,options)
            }
            R.id.fragmentThird -> {
                navController.navigate(R.id.fragmentThird,null,options)
            }
        }
         true
    }

最后，您应该防止相同的项目选择情况，以便您可以添加以下代码。

bottomNavigationView.setOnNavigationItemReselectedListener { item ->
        return@setOnNavigationItemReselectedListener

我在项目中使用了类似的 bottomNavigation 来为页面转换添加动画。
我希望它有所帮助。