类型不匹配。 必需：找到的上下文：在片段中

Question

In my SearchFragment.kt I have:

private lateinit var userDb: FirebaseFirestore
private lateinit var users: MutableList<User>
private lateinit var adapter: UsersAdapters

fun getUsers() {
    users = mutableListOf()
    adapter = UsersAdapters(this, users)

    userDb = FirebaseFirestore.getInstance()
    val userReference = userDb.collection("users")
    userReference.addSnapshotListener { snapshot, exception ->
        if (exception != null || snapshot == null) {
            Log.i("TAG", "Somethings Wrong", exception)
            return@addSnapshotListener
        }
        val userList = snapshot.toObjects(User::class.java)
        for (user in userList) {
            Log.i("TAG", "Document ${user.username}")
        }
    }
}

Which gets called in in onViewCreated

override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
    super.onViewCreated(view, savedInstanceState)
    getUsers()
}

My UserAdapter.kt look like:

package com.example.myapp

import android.content.Context
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.recyclerview.widget.RecyclerView
import com.bumptech.glide.Glide
import kotlinx.android.synthetic.main.item_user.view.*

import com.example.myapp.models.User


class UsersAdapters (val context: Context, val users: List<User>) :
    RecyclerView.Adapter<UsersAdapters.ViewHolder>() {

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

override fun getItemCount() = users.size

override fun onBindViewHolder(holder: ViewHolder, position: Int) {
    holder.bind(users[position])
}

inner class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
    fun bind(user: User) {
        itemView.etUsername.text = user?.username
        Glide.with(context).load(user.profileURL).into(itemView.profileImage)
    }
}
}

In SearchFragment.kt on the following line:

adapter = UsersAdapters(this, users)

Im getting the following error:

Type mismatch.
Required:
Context
Found:
SearchFragment

Answer 1

1. Do not pass the context to the adapter. Remove it, you don't need it.

2. When inflating your view, use parent.context instead of the outer context. you can also inline that return statement, like.

   return LayoutInflater.from(parent.context).inflate(R.layout.item_user, parent, false)

3. You are using Glide, within your ViewHolder class,

replace

Glide.with(context).load(user.profileURL).into(itemView.profileImage)

with

Glide.with(itemView).load(user.profileURL).into(itemView.profileImage)

Glide will take the view as a parameter. That works and it is the right way to write your code.

Answer 2

尝试这个：

adapter = UsersAdapters(requireActivity(), users)

Answer 3

In my case

class ModeradorFragment: Fragment() {
override fun onAttach(context: Context) {
    Log.d(Constraints.TAG, "onAttach")
    super.onAttach(context)
}

I put the on attach at the beginning of the class then use it in my linear layout

val layoutManager1 = LinearLayoutManager(context, LinearLayoutManager.HORIZONTAL, false)
val adapterpreg = PreguntasAdapter(this@ModeradorFragment, data)