将SearchView查询从起始片段传递到另一个片段

Question

在我的Fragment类中，我有这个：

override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
        inflater.inflate(R.menu.my_menu, menu)
        val searchItem = menu.findItem(R.id.action_search)
        searchView = searchItem.actionView as SearchView
        searchView.apply{
            queryHint = "Search"
            isIconified = false
            setOnQueryTextListener(object : SearchView.OnQueryTextListener{
                override fun onQueryTextSubmit(query: String): Boolean {
                    // pass the query to the other fragment and navigate to it
                    findNavController().navigate(GroupListFragmentDirections.actionGroupListFragmentToSearchedGroupListFragment(query))
                    return false
                }

                override fun onQueryTextChange(newText: String): Boolean {
                    // start the search
                    //groupListViewModel.searchGroups(newText)
                    return false
                }
            })
        }
    }

现在，发生的事情是我想将查询传递给另一个片段并导航到它。然后，另一个片段以某种方式处理查询。但是Android Studio告诉我SearchView没有设置NavController。这是我在LogCat中找到的错误消息：

java.lang.IllegalStateException: View androidx.appcompat.widget.SearchView{c83b4ef VFE...... ........ 147,10-987,136 #7f08003d app:id/action_search} does not have a NavController set
        at androidx.navigation.Navigation.findNavController(Navigation.java:84)
        at androidx.navigation.ViewKt.findNavController(View.kt:28)
        at com.celik.abdullah.mylim4.ui.GroupListFragment$onCreateOptionsMenu$1$1.onQueryTextSubmit(GroupListFragment.kt:93)
        at androidx.appcompat.widget.SearchView.onSubmitQuery(SearchView.java:1191)
        at androidx.appcompat.widget.SearchView$7.onEditorAction(SearchView.java:1168)
        at android.widget.TextView.onEditorAction(TextView.java:5911)
        at com.android.internal.widget.EditableInputConnection.performEditorAction(EditableInputConnection.java:138)
        at com.android.internal.view.IInputConnectionWrapper.executeMessage(IInputConnectionWrapper.java:360)
        at com.android.internal.view.IInputConnectionWrapper$MyHandler.handleMessage(IInputConnectionWrapper.java:85)
...

我使用Android Architecture Components中的NavigationUI库。 MainActivity的布局包含NavHostFragment布局小部件。您在上面看到的片段代码是起始片段（用户在打开应用程序时看到的片段）。

我假定不允许在searchview的侦听器内使用findNavController（）。不过，是否有办法将查询从搜索视图传递到下一个片段。

这是我的活动布局：

// activity_main.xml
<LinearLayout android:layout_width="match_parent"
    android:layout_height="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical"
    xmlns:android="http://schemas.android.com/apk/res/android">

        <fragment
            android:id="@+id/myNavHostFragment"
            android:name="androidx.navigation.fragment.NavHostFragment"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:defaultNavHost="true"
            app:navGraph="@navigation/navigation" />

</LinearLayout>

和这里是我的navigation.xml：

<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/groupListFragment">

    <fragment
        android:id="@+id/groupListFragment"
        android:name="com.celik.abdullah.mylim4.ui.GroupListFragment"
        android:label="GroupListFragment"
        tools:layout="@layout/fragment_group_list">
        <action
            android:id="@+id/action_groupListFragment_to_searchedGroupListFragment"
            app:destination="@id/searchedGroupListFragment" />
    </fragment>
    <fragment
        android:id="@+id/searchedGroupListFragment"
        android:name="com.celik.abdullah.mylim4.ui.SearchedGroupListFragment"
        android:label="SearchedGroupListFragment"
        tools:layout="@layout/fragment_searched_group_list">
        <argument
            android:name="query"
            app:argType="string" />
    </fragment>
</navigation>

Answer 1

如果您在SearchView中使用Toolbar，则应在导航中设置Toolbar：