问Android给了我: Type参数不在它的范围之内:应该是'RecyclerView.ViewHolder!‘的子类型！

EN

import android.view.View
import android.view.ViewGroup
import android.widget.TextView
import androidx.recyclerview.widget.RecyclerView
import com.surajpatil.navigationdrawer1.R

class DashboardRecyclerAdapter : RecyclerView.Adapter<DashboardRecyclerAdapter.DashboardViewHolder>(){

    class DashboardViewHolder(view:View)
    {
        val textView: TextView = view.findViewById(R.id.txtRecyclerRowItem)

    }

    override fun onCreateViewHolder(parent: ViewGroup , viewType: Int): DashboardViewHolder {
        TODO("Not yet implemented")
    }

    override fun onBindViewHolder(holder: DashboardViewHolder , position: Int) {
        TODO("Not yet implemented")
    }

    override fun getItemCount(): Int {
        TODO("Not yet implemented")
    }
}