在带有导航组件的BottomNavigationView中传递参数

时间:2018-12-30 00:15:40

标签: kotlin androidx

我目前正在使用新的(对我来说)导航组件编写应用程序。我已经用一个导航图来浏览我的应用程序的基础知识,我有一个带有BottomNavigationView的片段,其中有3个单独的片段,我设法将其更新为使用导航组件(到目前为止我的问题)使用具有与导航项匹配的ID的菜单。我以前所有使用newInstance方法将捆绑包传递给onCreate的片段现在显然都没有使用,但是我仍然需要将捆绑包传递给我的片段。

由于片段是隐式创建的,因此我无法找到完成此操作的任何示例。

我的代码的结构为ClientFragment,这是导航抽屉等的主机片段;

class ClientFragment : Fragment() {

    private val viewModel: ClientViewModel by viewModel()

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

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

       viewModel.client = arguments?.getParcelable(ARG_CLIENT)!!

        toolbar_client.title = viewModel.client.name
        toolbar_client.setNavigationOnClickListener { Navigation.findNavController(view).navigateUp() }
    }
}

该类以前使用onView侦听器来监视我的片段,并带有一个newInstance方法,该方法使用viewModel.client工具。

我在nav_graph中的片段都是相似的。第一个片段;

class ClientDetailsFragment : Fragment() {

    private val viewModel: ClientViewModel by viewModel()

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

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

       // viewModel.client = arguments?.getParcelable(ARG_CLIENT)!!

        initClientDetails()
    }

    private fun initClientDetails() {
//        text_client_details_name.text = viewModel.client.name
//        text_client_details_account_number.text = viewModel.client.accountNumber
//        text_client_details_mobile_number.text = viewModel.client.mobileNumber
//        text_client_details_landline_number.text = viewModel.client.landlineNumber
//        text_client_details_email.text = viewModel.client.email
//        text_client_details_address.text = "NOT YET IMPLEMENTED"
//
//        text_client_description_body.text = viewModel.client.description
//        text_client_system_details_body.text = viewModel.client.systemDetails
    }
}

应用程序在注释行上崩溃;

// viewModel.client = arguments?.getParcelable(ARG_CLIENT)!! 

我的导航图和菜单是;

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/client_nav_graph"
    app:startDestination="@id/clientDetailsFragment">

    <fragment
        android:id="@+id/clientCustomersFragment"
        android:name="com.management.engineering.alarm.alarmengineermanagement.features.client.ClientCustomersFragment"
        android:label="ClientCustomersFragment"
        tools:layout="@layout/fragment_client_customers" />

    <fragment
        android:id="@+id/clientDetailsFragment"
        android:name="com.management.engineering.alarm.alarmengineermanagement.features.client.ClientDetailsFragment"
        android:label="ClientDetailsFragment"
        tools:layout="@layout/fragment_client_details"/>

    <fragment
        android:id="@+id/clientJobHistoryFragment"
        android:name="com.management.engineering.alarm.alarmengineermanagement.features.client.ClientJobHistoryFragment"
        android:label="ClientJobHistoryFragment"
        tools:layout="@layout/fragment_client_job_history" />

</navigation>

菜单;

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:id="@+id/clientDetailsFragment"
        android:icon="@drawable/ic_launcher_foreground"
        android:title="Details"/>
    <item
        android:id="@+id/clientJobHistoryFragment"
        android:icon="@drawable/ic_launcher_foreground"
        android:title="Job History"/>
    <item
        android:id="@+id/clientCustomersFragment"
        android:icon="@drawable/ic_launcher_foreground"
        android:title="Customers"/>
</menu>

我发现您可以向导航图添加参数,但是对于这种特定情况,并没有找到将它们放置在何处的信息,我也知道能够在使用.navigate进行导航时手动添加包。

我是否可以在ClientFragment中为每个片段设置参数

viewModel.client

更新:

我的自变量问题是通过使用在BottomNavigationView中的所有片段之间共享的视图模型解决的(我在向朋友键入问题时意识到了这一点),并且导航本身将其添加到ClientFragment; / p>

bottom_nav_client.setupWithNavController(
            Navigation.findNavController(
                    view.findViewById<View>(R.id.fl_client_nav_container)
            )
    )

和我用于fragment_client的xml;

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout  xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <androidx.appcompat.widget.Toolbar
        android:id="@+id/toolbar_client"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:background="@color/colorPrimary"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:navigationIcon="?attr/NavigationBackIconLight"
        app:titleTextColor="@color/white" />

    <fragment
        android:id="@+id/fl_client_nav_container"
        android:name="androidx.navigation.fragment.NavHostFragment"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layout_constraintBottom_toTopOf="@id/bottom_nav_client"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/toolbar_client"
        app:navGraph="@navigation/client_nav_graph" />

    <com.google.android.material.bottomnavigation.BottomNavigationView
        android:id="@+id/bottom_nav_client"
        android:layout_width="match_parent"
        android:layout_height="56dp"
        android:background="?android:attr/windowBackground"
        app:itemBackground="@color/colorPrimary"
        app:itemIconTint="@drawable/bottom_nav_color"
        app:itemTextColor="@color/white"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:menu="@menu/client_menu" />

</androidx.constraintlayout.widget.ConstraintLayout>

与上面显示的相同导航图和菜单结合在一起。

3 个答案:

答案 0 :(得分:3)

接受的答案中提到的代码实验室没有提及将参数传递给BottomNavigationView中的片段。

使用自定义参数覆盖由setupWithNavController()设置的OnNavigationItemSelectedListener:

val args = Bundle()

bottomNavigationView.setupWithNavController(navController)
bottomNavigationView.setOnNavigationItemSelectedListener { item ->
    navController.navigate(item.itemId, args)
    true
}

答案 1 :(得分:0)

导航体系结构组件 documentation显示了如何定义目标参数,在具体情况下,您应该创建一个自定义Parcelable类(即Client),并将其作为相应片段的参数。

<fragment
    android:id="@+id/clientCustomersFragment"
    android:name="com.management.engineering.alarm.alarmengineermanagement.features.client.ClientCustomersFragment"
    android:label="ClientCustomersFragment"
    tools:layout="@layout/fragment_client_customers" >

    <action
        android:id="@+id/client_to_details"
        app:destination="@+id/clientDetailsFragment" />

</fragment>

<fragment
    android:id="@+id/clientDetailsFragment"
    android:name="com.management.engineering.alarm.alarmengineermanagement.features.client.ClientDetailsFragment"
    android:label="ClientDetailsFragment"
    tools:layout="@layout/fragment_client_details">

    <argument
        android:name="client"
        app:argType="com.management.engineering.alarm.alarmengineermanagement.features.client.Client" />

</fragment>

'androidx.navigation.safeargs' gradle插件将生成可用于传递的类ClientToDetailsClientDetailsFragmentArgs。检索参数client

来源

val client: Client = TODO()
val navController: NavController = TODO()
navController.navigate(ClientToDetails(client))

目的地

val client =  ClientDetailsFragmentArgs.fromBundle(arguments).client

答案 2 :(得分:0)