RecyclerView

关于RecyclerView和ListView，不多说什么，简单RecyclerView用法，性能更好但是相对稍微复杂一丢丢：

• layout.xml

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/exp_data_list"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

• Adapter, with simple callback of click on a item

class SimpleListAdapter(private var listData: Array<String>) : RecyclerView.Adapter<SimpleListAdapter.Companion.ViewHolder>() {
    private var clickCallback: ((String) -> Unit)? = null
    fun setClickCallback(callback: (String) -> Unit): SimpleListAdapter {
        clickCallback = callback
        return this
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder {
        return ViewHolder(LayoutInflater.from(parent.context).inflate(R.layout.simple_list_item, parent, false))
    }

    override fun onBindViewHolder(holder: ViewHolder, position: Int) {
        val item = listData[position]
        holder.textView?.text = item
        holder.textView?.setOnClickListener { clickCallback?.invoke(item) }
    }

    override fun getItemCount(): Int {
        return listData.size
    }

    companion object {
        class ViewHolder(rootView: View) : RecyclerView.ViewHolder(rootView) {
            val textView: TextView? = rootView.findViewById(R.id.item_text)
        }
    }
}

• Use it! In Activity or else.

val data = arrayOf("hello", "monday", "happy", "yes", "sounds", "loving", "holiday", "good", "cuty", "wonderful", "andrew", "bell", "custom")
val dataRecyclerView = findViewById(R.id.exp_data_list)
val adapter = SimpleListAdapter(data).setClickCallback { result ->
    Toast.makeText(this, "Click page on $result", Toast.LENGTH_SHORT).show()
}
dataRecyclerView?.layoutManager = LinearLayoutManager(this, RecyclerView.VERTICAL, false)
dataRecyclerView?.adapter = adapter

That's it.

SearchView

Usage

• layout.xml, two elements, one for search box one for search result

   <androidx.appcompat.widget.SearchView
        android:id="@+id/exp_searchView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="textFilter" />

    <TextView
        android:id="@+id/exp_content"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/design_default_color_primary"
        android:padding="10dp"
        android:text="hello"
        android:visibility="gone" />

• use it, with SearchAutoComplete

val data = arrayOf("hello", "monday", "happy", "yes", "sounds", "loving", "holiday", "good", "cuty", "wonderful", "andrew", "bell", "custom")
val searchView = findViewById(R.id.exp_searchView)
val searchResultView = findViewById(R.id.exp_content)
val searchAutoComplete = searchView?.findViewById(androidx.appcompat.R.id.search_src_text) as SearchView.SearchAutoComplete
val simpleAdapter = ArrayAdapter(this, android.R.layout.simple_list_item_1, data)
searchAutoComplete.setAdapter(simpleAdapter)
searchAutoComplete.threshold = 1
searchAutoComplete.setOnItemClickListener { parent, view, position, id ->
    val result = simpleAdapter.getItem(position)
    Toast.makeText(this, "Click on $result", Toast.LENGTH_SHORT).show()
    searchResultView?.visibility = View.VISIBLE
    searchResultView?.text = result
}

效果就是，点击搜索按钮，进入搜索页面，有输入就会开始匹配，输入框下会显示列表展示可选的项，点击可选项后会触发callback，弹一个toast同时一个textview展示结果。