android kotlin 如何从回收器视图中删除项目

Question

我正在使用 Kotlin ，当我从 Recyclerview 中删除该项目时，它会重新排列列表中的项目，这就是我的编码方式。我在java中也做了同样的事情，但在java中它工作得很好。但在 kotlin 中它会产生问题。

                mylist.removeAt(position)
                notifyItemRemoved(position)
                notifyItemRangeChanged(position,mylist.size)

这是我的代码，用于删除适配器中的项目，下面是我如何在列表中设置数据

                class Gallery_adm_adp(
val mylist: ArrayList<Model_class_one>,
val fragmentActivity: FragmentActivity,
val pages: Int
      ) :
      RecyclerView.Adapter<Gallery_adm_adp.Viewholder>() {
      var currentpage = 2
      lateinit var loadmore: RelativeLayout
       lateinit var image: ImageView
         lateinit internal var edit_menu: ImageView


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

    @SuppressLint("ShowToast")
    fun mydata(list: Model_class_one?, position: Int) {
        edit_menu = itemView.findViewById(R.id.edit_menu)
        Log.i("List_check", "running position>> " + position)
        loadmore.visibility = View.GONE

        Glide.with(fragmentActivity).load(list!!.Image).into(image)

        if (position == mylist.size - 1) {
            if (pages >= currentpage) {
                loadmore.setVisibility(View.VISIBLE)
                callnextapi()
            } else {
                loadmore.setVisibility(View.GONE)
            }
        } else {
            loadmore.setVisibility(View.GONE)
        }

        edit_menu.setOnClickListener {


            val id = list.ID
            popup(itemView, id, position)
            Log.d("clicks", "position" + position)
        }
    }
}

private fun popup(itemView: View, id: String, position: Int) {
    val popup: PopupMenu
    popup = PopupMenu(fragmentActivity, itemView.edit_menu)
    popup.inflate(R.menu.menu_delete)
    popup.setOnMenuItemClickListener { item ->
        when (item.itemId) {
            R.id.delete -> {
                showdialog(id, position)
            }
        }
        false
    }
    //displaying the popup
    popup.show()
}

private fun showdialog(ids: String, position: Int) {
    val builder = AlertDialog.Builder(fragmentActivity)
    builder.setTitle("Delete")
        .setMessage("Do You Want to delete this post")
        .setCancelable(false)
        .setPositiveButton("Yes") { dialog, id ->
            deleteitem(ids, position)
        }.setNegativeButton("No") { dialogInterface, i ->
        }
    val alert = builder.create()
    alert.show()
}

private fun toast(text: String) {
    ((fragmentActivity as MainActivity_Admin).customtoast(text))
    Toast.makeText(fragmentActivity, text, Toast.LENGTH_SHORT).show()
}

private fun deleteitem(id: String, position: Int) {
    val requestQueue = Volley.newRequestQueue(fragmentActivity)
    val URL = Constant.DeleteGallery + id
    val stringRequest = object : StringRequest(Request.Method.POST, URL,
        Response.Listener { response ->
            Log.i("VOLLEY_res", "my responce>>$response")
            try {
                val result = response
                toast(result)
                mylist.removeAt(position)
                notifyItemRemoved(position)
                notifyItemRangeChanged(position, mylist.size)

            } catch (e: JSONException) {
                e.printStackTrace()
                toast("Can't Delete .. Please Try Again")
            }
        }, Response.ErrorListener { error ->
            toast("Check Internet Connection and Try Again")
        }) {
    }
    requestQueue.add(stringRequest)

}


override fun getItemViewType(position: Int): Int {
    return position
}

private fun callnextapi() {
    val requestQueue = Volley.newRequestQueue(fragmentActivity)
    val URL = Constant.Gallery + currentpage

    val stringRequest = object : StringRequest(Request.Method.POST, URL,
        Response.Listener { response ->
            try {
                val result = JSONObject(response)
                val ListDetails = result.getJSONArray("ListDetails")
                val length = ListDetails.length()
                for (i in 0 until length) {
                    val objJson = ListDetails.getJSONObject(i)
                    val ID = objJson.getString("ID")
                    val UserName = objJson.getString("UserName")
                    val Image = objJson.getString("Image")
                    val UserID = objJson.getString("UserID")
                    var Date = objJson.getString("Date")
                    Date = Date.replace("12:00:00 AM","")
                    mylist.add(Model_class_one(ID, UserName, Image, UserID,Date))
                }
                notifyDataSetChanged()
                currentpage = currentpage + 1

            } catch (e: JSONException) {
                e.printStackTrace()
            }
        }, Response.ErrorListener { error ->
        }) {
    }
    requestQueue.add(stringRequest)

}

override fun onCreateViewHolder(parent: ViewGroup, p1: Int): Gallery_adm_adp.Viewholder {
    val layout = LayoutInflater.from(fragmentActivity as Context?).inflate(R.layout.gallery_adp_admin, parent, false)
    loadmore = layout.findViewById(R.id.loadmore)
    image = layout.findViewById(R.id.image)
    return Viewholder(layout)
}

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

override fun onBindViewHolder(holder: Gallery_adm_adp.Viewholder, position: Int) {
              val Values = mylist[position]
                holder.mydata(Values, position)
              }

              }

//这里有一些图像，您可以很好地理解列表是如何洗牌的

我的第一个清单

删除了该项目

变化

再次完成

看看下一步

看下一步6

它甚至显示已删除的项目..我希望你给我提出好主意

感谢大家的帮助。我已尽力提供帮助。

Answer 1

在您的 Kotlin 项目中尝试此适配器将帮助您：-

import android.support.v7.widget.RecyclerView
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import com.gropse.dentalsafety.R
import com.gropse.dentalsafety.pojo.GetPlanListResultDentist
import com.gropse.serviceme.utils.AppConstants
import kotlinx.android.synthetic.main.subscription_list_item.view.*
import java.util.*

class PlanListAdapter( private var listener: OnItemClick?) : RecyclerView.Adapter<PlanListAdapter.CategoryViewHolder>() {
    private val list = ArrayList<GetPlanListResultDentist>()
    private  var type= AppConstants.ACTION_NOTHING

    interface OnItemClick {
        fun onClick(bean: GetPlanListResultDentist, type: Int)
    }

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

    override fun onBindViewHolder(holder: CategoryViewHolder, position: Int) {
        holder.onBind(position)
    }

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

    fun removeItem(position: Int) {
        list.remove(position)
        notifyDataSetChanged()
    }

    fun addList(newList: ArrayList<GetPlanListResultDentist>) {
        list.addAll(newList)
        notifyDataSetChanged()
    }

    fun clear() {
        list.clear()
        notifyDataSetChanged()
    }

    inner class CategoryViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView), View.OnClickListener {

        init {
            itemView.setOnClickListener(this)
            itemView.viewList.setOnClickListener(this)
            itemView.editData.setOnClickListener(this)
            itemView.clearItem.setOnClickListener(this)
        }

        fun onBind(position: Int) {
            itemView.tag = position
            itemView.viewList.tag = position
            itemView.editData.tag = position
            itemView.clearItem.tag = position
            val bean = list[position]
            itemView.monthlyrateTV.setText(bean.monthly_fee+"$")
            itemView.yearlyrateTV.setText(bean.yearly_fee+"$")
            itemView.noofferTV.text = bean.services?.size.toString()+" "+"Service Offered"
            if (bean.user_type.equals("0")) {
                itemView.usertypeTV.setText("Adult")
            } else {
                itemView.usertypeTV.setText("Child")
            }


        }

        override fun onClick(v: View) {
            when(v?.id){
                R.id.viewList->{
                    type=AppConstants.TYPE_VIEW_LIST
                }
                R.id.editData->{
                    type=AppConstants.TYPE_EDIT_LIST
                }
                R.id.clearItem->{
                    type=AppConstants.TYPE_CLEAR_LIST
                }
                else->{
                    type=AppConstants.ACTION_NOTHING
                }
            }
            if (listener != null) listener?.onClick(list[v.tag as Int], type)


        }
    }
}