将功能 SearchView 添加到一个特定的 Fragment

Question

我有一个片段，我想在其中添加一个 SearchView。我已经在菜单中找到了它，它的可点击和所有内容，但我发现的每个实际搜索内容的指南要么已过时，要么不完全符合我的需要。

这是我的片段

    class ViewFragment : Fragment () {

    override fun onCreateView(inflater: LayoutInflater,container: ViewGroup?,
savedInstanceState: Bundle?
    ): View? {
        val binding: ViewFragmentBinding = DataBindingUtil.inflate(
            inflater, R.layout.view_fragment, container, false)

        val application = requireNotNull(this.activity).application

        setHasOptionsMenu(true)
        binding.setLifecycleOwner(this)

        viewFragmentViewModel.navigateToEdit.observe(this, Observer {translation ->
            translation?.let {
                this.findNavController().navigate(
                    ViewFragmentDirections
                        .actionViewFragmentToEditFragment(translation)
                )
                viewFragmentViewModel.onEditNavigated()
            }
        })

        val adapter = TranslationAdapter(TranslationListener { translationID ->
            viewFragmentViewModel.onTranslationClicked(translationID)
        })
        binding.translationList.adapter = adapter

        viewFragmentViewModel.translations.observe(viewLifecycleOwner, Observer {
            it?.let {
                adapter.submitList(it)
            }
        })

        return binding.root
    }

    override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater){
        inflater.inflate(R.menu.search_menu, menu)
        super.onCreateOptionsMenu(menu, inflater)

    }

这是我的搜索菜单

<menu 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:layout_width="match_parent"
    android:layout_height="match_parent">


    <item
        android:id="@+id/action_search"
        android:icon="@android:drawable/ic_menu_search"
        app:showAsAction="always|collapseActionView"
        app:actionViewClass="android.widget.SearchView"
        android:title="Search"/>
</menu>

谁能告诉我如何设置所有内容，以便我可以访问用户输入的搜索字符串并将新列表提交到 RecycleView？或者只是指出我正确的方向！

提前谢谢你！

编辑：这是更新。我有一个 MutableLiveData 我在其中放置查询并观察它，以便我可以对它的观察功能采取行动。我在要更新的 ViewModel 中有一个变量 translationList。

class ViewFragment : Fragment (), SearchView.OnQueryTextListener {


private var searchText = MutableLiveData<String>()

override fun onCreateView(
    inflater: LayoutInflater,
    container: ViewGroup?,
    savedInstanceState: Bundle?
): View? {

...

    val adapter = TranslationAdapter(TranslationListener { translationID ->
        viewFragmentViewModel.onTranslationClicked(translationID)
    })
    binding.translationList.adapter = adapter

    viewFragmentViewModel.translations.observe(viewLifecycleOwner, Observer {
        it?.let {
            adapter.submitList(it)
        }
    })

    searchText.observe(this, Observer {searchString ->
        searchString?.let {
            if(searchString == ""){
                adapter.submitList(viewFragmentViewModel.translations.value)
            }
            else{
                adapter.submitList(viewFragmentViewModel.searchTranslations(searchString))
            }

        }
    })

}

override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater){
    inflater.inflate(R.menu.search_menu, menu)

    val menuItem = menu.findItem(R.id.action_search)
    val searchView = menuItem.actionView as SearchView
    searchView.setOnQueryTextListener(this)
    super.onCreateOptionsMenu(menu, inflater)
}

override fun onQueryTextChange(newText: String?): Boolean {

    searchText.value = newText
    return true
}

override fun onQueryTextSubmit(query: String?): Boolean {
    return false
}

}

对于闭包，由于我已经有一个列表，其中包含我想要搜索的数据库中的所有对象，因此只需使用过滤器浏览该列表就更容易了。

Answer 1

步骤 - 1： 在您的 ViewFragment 中实现 SearchView.OnQueryTextListener

class ViewFragment : Fragment(), SearchView.OnQueryTextListener {

    ...

    override fun onQueryTextSubmit(query: String?): Boolean {
        return false
    }

    override fun onQueryTextChange(newText: String?): Boolean {

        //Do your operation here

        return true
    }
}

步骤 - 2： 从菜单中获取 SearchView 并使用侦听器进行初始化

override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
    inflater.inflate(R.menu.search_menu, menu)

    val meniItem = menu?.findItem(R.id.action_search)
    val searchView = meniItem?.actionView as SearchView?
    searchView?.setOnQueryTextListener(this)

    super.onCreateOptionsMenu(menu, inflater)
}

第 3 步：在 onQueryTextChange 内部获取您的搜索查询并执行操作

更新：如下更改您的实现：

fun searchTranslations(searchString: String) : List<Translation>? {
    return database.getTranslationsBySearch(searchString).value
}

和道

@Query("SELECT * FROM word_translation_table WHERE word_ger LIKE '% :string %'  OR word_es LIKE '% :string %' ")
fun getTranslationsBySearch(string: String): LiveData<List<Translation>>