导航架构组件 - 对话框片段

Question

是否可以使用带有DialogFragment的新导航架构组件？我是否必须创建自定义导航器？

我很乐意将它们与导航图中的新功能结合使用.

Answer 1

May 2019 Update:

DialogFragment are now fully supported starting from Navigation 2.1.0-alpha03, you can read more here and here

Old Answer for Navigation <= 2.1.0-alpha02:

I proceeded in this way:

1) Update Navigation library at least to version 2.1.0-alpha01 and copy both files of this modified gist in your project.

3) Then in your navigation host fragment, change the name parameter to your custom NavHostFragment

<fragment
    android:id="@+id/nav_host_fragment"
    android:name="com.example.app.navigation.MyNavHostFragment"
    app:defaultNavHost="true"
    app:navGraph="@navigation/nav_graph"
    android:layout_width="0dp"
    android:layout_height="0dp"
    app:layout_constraintBottom_toBottomOf="parent"
    app:layout_constraintEnd_toEndOf="parent"
    app:layout_constraintStart_toStartOf="parent"
    app:layout_constraintTop_toBottomOf="@id/toolbar" />

4) Create your DialogFragment subclasses and add them to your nav_graph.xml with:

<dialog
    android:id="@+id/my_dialog"
    android:name="com.example.ui.MyDialogFragment"
    tools:layout="@layout/my_dialog" />

5) Now launch them from fragments or activity with

findNavController().navigate(R.id.my_dialog)

or similar methods.

Answer 2

不,在1.0.0-alpha01构建时,作为导航图的一部分,不支持对话框.您应该继续使用show()来显示DialogFragment.

Answer 3

是的，这是可能的，您可以通过调用从对话框片段访问父片段的视图 getParentFragment().getView()。并使用视图进行导航。

这是例子

Navigation.findNavController(getParentFragment().getView()).navigate(R.id.nextfragment);

Answer 4

是的。该框架的制作方式是，您可以Navigator为非开箱即用的视图创建一个扩展抽象类的类，并将其添加到您NavController的方法中getNavigatorProvider().addNavigator(Navigator navigator)

如果您正在使用NavHostFragment，您还需要扩展它以添加自定义导航器或仅创建您自己的MyFragment实现NavHost接口。它非常灵活，您可以使用 中定义的自定义属性创建自己的 xml 参数values，就像创建自定义视图一样。像这样的东西（未测试）：

@Navigator.Name("dialog-fragment")
class DialogFragmentNavigator(
        val context: Context,
        private val fragmentManager: FragmentManager
) : Navigator<DialogFragmentNavigator.Destination>() {

    override fun navigate(destination: Destination, args: Bundle?,
                          navOptions: NavOptions?, navigatorExtras: Extras?
    ): NavDestination {
        val fragment = Class.forName(destination.name).newInstance() as DialogFragment
        fragment.show(fragmentManager, destination.id.toString())
        return destination
    }

    override fun createDestination(): Destination = Destination(this)

    override fun popBackStack() = fragmentManager.popBackStackImmediate()

    class Destination(navigator: DialogFragmentNavigator) : NavDestination(navigator) {

        // The value of <dialog-fragment app:name="com.example.MyFragmentDialog"/>
        lateinit var name: String

        override fun onInflate(context: Context, attrs: AttributeSet) {
            super.onInflate(context, attrs)
            val a = context.resources.obtainAttributes(
                    attrs, R.styleable.FragmentNavigator
            )
            name = a.getString(R.styleable.FragmentNavigator_android_name)
                    ?: throw RuntimeException("Error while inflating XML. " +
                            "`name` attribute is required")
            a.recycle()
        }
    }
}

用法

my_navigation.xml

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

    <fragment
        android:id="@+id/navigation_assistant"
        android:name="com.example.ui.HomeFragment"
        tools:layout="@layout/home">
        <action
            android:id="@+id/action_nav_to_dialog"
            app:destination="@id/navigation_dialog" />
    </fragment>

    <dialog-fragment
        android:id="@+id/navigation_dialog"
        android:name="com.example.ui.MyDialogFragment"
        tools:layout="@layout/my_dialog" />

</navigation>    

将导航的片段。

class HomeFragment : Fragment(), NavHost {

    private val navControllerInternal: NavController by lazy(LazyThreadSafetyMode.NONE){
        NavController(context!!)
    }

    override fun getNavController(): NavController = navControllerInternal

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        // Built-in navigator for `fragment` XML tag
        navControllerInternal.navigatorProvider.addNavigator(
            FragmentNavigator(context!!, childFragmentManager, this.id)
        )
        // Your custom navigator for `dialog-fragment` XML tag
        navControllerInternal.navigatorProvider.addNavigator(
            DialogFragmentNavigator(context!!, childFragmentManager)
        )
        navControllerInternal.setGraph(R.navigation.my_navigation)
    }

    override fun onCreateView(inflater: LayoutInflater, 
                              container: ViewGroup?, savedInstanceState: Bundle?): View? {
        super.onCreateView(inflater, container, savedInstanceState)
        val view = inflater.inflate(R.layout.home)
        view.id = this.id

        view.button.setOnClickListener{
            getNavController().navigate(R.id.action_nav_to_dialog)
        }

        return view
    }
}