Kotlin 在 RecycleView 项目中打开 AlertDialog 点击

Question

我有RecyclerView，我想在单击RecyclerView 的项目时打开AlertDialog，我正在尝试遵循This java based Question 的概念，但它对我不起作用

我的适配器

class OperationAdapter (val context: Context,private val arrayList: ArrayList <Operations>):
RecyclerView.Adapter <OperationAdapter.Holder> () {

companion object {
    val TAG: String = OperationAdapter::class.java.simpleName
}

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

override fun getItemCount (): Int = arrayList. size

override fun onBindViewHolder (holder: Holder, position: Int) {

    val opera = arrayList[position]
    holder.setData(opera, position)

}

inner class Holder (itemView: View): RecyclerView.ViewHolder (itemView) {

    private var currentOpera: Operations? = null
    private var currentPosition: Int = 0


    init {

        itemView.cardview.setOnClickListener {
            currentOpera?.let {

                AlertDialog.Builder(context)
                    .setTitle("My Title")
                    .setMessage("My Message")
                    .create()
                    .show()

            }
        }

        //the end of the init
    }

    //getting data from Operations and bind it into View
    fun setData(operation: Operations?, position: Int) {
        operation?.let {
            itemView.txtphonenumber.text = operation.phone
            itemView.txttime.text = operation.etime
        }

        this.currentOpera = operation
        this.currentPosition = position
    }
}

设置回收视图

//set up the recycleview
    mRecyclerView.setHasFixedSize (true)
    mRecyclerView. layoutManager = LinearLayoutManager(this)

          //adapter
          val adapter = OperationAdapter(applicationContext,arrayList)
                        adapter.notifyDataSetChanged()
                        mRecyclerView.adapter = adapter

请给点建议

Answer 1

Your code works我检查并复制了您的适配器代码，它可以工作，请将您的 xml 布局和启动该适配器的代码发送给我

更新：

您不能发送 applicationContext，您应该发送您的活动的上下文。 修复那个val adapter = OperationAdapter(this, arrayList）你不能在应用程序类中创建一个对话框，因为对话框应该附加到一个窗口，一个应用程序不是UI类并且没有窗口，所以它不能显示对话框。

Answer 2

首先，永远不要将你的 onclick 放在 onBindViewHolder 中。那不是一个好习惯。其次，如果您想在 item 上执行任何点击事件，您可以选择接口或将您的 item 点击监听器放在扩展 RecyclerView.ViewHolder 的 ViewHolder 类（内部类）中。

item.setOnClickListenr{
  AlertDialog.Builder(this)
            .setTitle("My Title")
            .setMessage("My Message"))
            .setPositiveButton("Yes") { dialog, which -> todoFunctiononpositiveclick() }
            .setNegativeButton("No") { dialog, which -> dialog.dismiss() }
            .show()
 }

使用此链接可以更好地了解使用接口 https://android.jlelse.eu/click-listener-for-recyclerview-adapter-2d17a6f6f6c9 与适配器进行交互

Answer 3

你忘记了 create()

val alertDialog = AlertDialog.Builder(context)
        .setTitle("My title")
        .setCancelable(true)
        .setMessage("My message")
        .create()

        alertDialog.show()

希望对你有帮助