Kotlin：获取点击项目列表视图的值（片段+适配器）

Posted 2023-05-07

【中文标题】Kotlin：获取点击项目列表视图的值（片段+适配器）

【英文标题】：Kotlin : get value of the clicked item list view (Fragment + Adapter)

【发布时间】：2019-06-06 10:42:04

【问题描述】：

我正在尝试从 ListView 之外的列表视图中获取单击的值。当我单击我的项目时，我想在我的片段中填充一个 textView。

在片段中，我有一个 searchView 和 ListView。

这是我的适配器：

class ListAdapterHoraire (context: Context, resource: Int, list: ArrayList<String>, private val arguments: Bundle?, private val forScol : Boolean) : ArrayAdapter<String>(context, resource, list) 

    private val TAG = ListAdapterCustom::class.java.simpleName
    var nameArret: String = ""

    override fun getView(position: Int, convertView: View?, parent: ViewGroup): View 
        val view = super.getView(position, convertView, parent)

        val arret = view.findViewById<TextView>(R.id.arret)
        val receivedBundle = arguments    
        arret.setOnClickListener 
            val fragment = HorairePassage()
            fragment.arguments = receivedBundle
            nameArret = arret.text.toString()
            Log.i(TAG, "$arret.text clicked")
            getArretCode(arret.text.toString(), fragment) //récupération du code arret + changement de fragment (en cascade)
        

        if (position % 2 == 1) 
            view.setBackgroundResource(R.color.colorWhite)
         else 
            view.setBackgroundResource(R.color.grayBackground)
        



        return view
    

片段的一部分：

search.setOnQueryTextListener(object : android.support.v7.widget.SearchView.OnQueryTextListener 
            override fun onQueryTextSubmit(newText: String): Boolean 
                return false
            

            override fun onQueryTextChange(newText: String): Boolean 
                if(newText.length > 3)
                    loadingArretSearch.visibility = View.VISIBLE
                    getListeArrets(view, newText.trim(), resultArgument)
                    adapter = ListAdapterHoraire(view.context, R.layout.list_adapter, lignes, resultArgument, false)
                    listSearchView.adapter = adapter
                    adapter.filter.filter(newText.trim())
                    if(newText.trim() != "")
                        listSearchView.visibility = View.VISIBLE
                    else
                        listSearchView.visibility = View.GONE
                    
                else
                    lignes.clear()
                    loadingArretSearch.visibility = View.GONE
                    listSearchView.visibility = View.GONE
                
                return false

            

        )

【参考方案1】：

对于这样的情况 --> 尝试将回调传递给适配器，然后您可以从您的活动中使用任何方法，然后您可以从您的活动中做您想做的事情。

class MyRecyclerViewAdapter(params , val itemClick: (Int) -> Unit): RecyclerView.Adapter<RecyclerView.ViewHolder>() 
    internal inner class MyViewHolder(view: View) : RecyclerView.ViewHolder(view) 
        ...
        itemView.setOnClickListener( itemClick(layoutPosition) )
    


In your fragment or Activity 

val myAdapter = MyRecyclerViewAdapter(params)  position ->
    // do something
 

--> 你的情况

ListAdapterHoraire(view.context, R.layout.list_adapter, lignes, resultArgument, false)value->
  // do something
  

class ListAdapterHoraire (context: Context, resource: Int, list: ArrayList<String>, private val arguments: Bundle?, private val forScol : Boolean,onItemClicked: (text: String) -> Unit) : ArrayAdapter<String>(context, resource, list) 

         ...


         arret.setOnClickListener  onItemClicked(arret.text.toString()) 

         ...

        

【讨论】：

你能在没有回收站视图的情况下调整这个吗？

你可以看看这个例子吗

adapter = ListAdapterHoraire(view.context, R.layout.list_adapter, lignes, resultArgument, false) value -> Log.i(TAG, "clicked value $value")

和你的适配器

arret.setOnClickListener onItemClicked(arret.text.toString())

【参考方案2】：

尝试在构造函数中传递一个函数作为参数，并在调用 onClickListener 时调用它：

class ListAdapterHoraire (context: Context, resource: Int, list: ArrayList<String>, private val arguments: Bundle?, private val forScol : Boolean,
 private val onItemClicked: (text: String) -> Unit) : ArrayAdapter<String>(context, resource, list)        
         ...


         arret.setOnClickListener  onItemClicked(arret.text.toString()) 

         ...

        

所以，在你的片段中更新适配器实例

adapter = ListAdapterHoraire(view.context, R.layout.list_adapter, 
             lignes, resultArgument, false,
              text -> Log.i("TAG", text) /** Do something here **/ )
 ...

【讨论】：

我不明白...并且在我的适配器中未检测到“onItemClicked”