Question

我想在recyclerview项目上实现onClickListener。这是我的 CustomAdapter.kt 代码。

import pygame
import os
import sys

pygame.init()
screen = pygame.display.set_mode((448, 576))
done = False

y = 320
x = 216

clock = pygame.time.Clock()
PACMANSPRITE = pygame.image.load("pacman.png").convert_alpha()

class pacman(pygame.sprite.Sprite):
    def __init__(self, image, x, y):
        self.image = image
        self.y=y
        self.x=x
        screen.blit((image), (x,y))


    def movement(self):
        pressed= pygame.key.get_pressed()
        if pressed[pygame.K_UP]:
            self.y=y-10
        if pressed[pygame.K_DOWN]:
            self.y=y+10
        if pressed[pygame.K_LEFT]:
            self.x=x-10
        if pressed[pygame.K_RIGHT]:
            self.x=x+10
        screen.blit(image, (x,y))

while not done:
        for event in pygame.event.get():
                if event.type == pygame.QUIT:
                        done = True
                        pygame.quit()
                        sys.exit()

        screen.fill((0, 0, 0))


        pacman(PACMANSPRITE, x ,y)
        pacman.movement()



        pygame.display.flip()
        clock.tick(60)

我想从我的活动中点击监听器回调。

Answer 1

class CustomAdapter(
    val userList: List<User>, 
    val listener: (User) -> Unit
) : RecyclerView.Adapter<CustomAdapter.ViewHolder>() {

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CustomAdapter.ViewHolder = ViewHolder(LayoutInflater.from(parent.context).inflate(R.layout.row_layout, parent, false))

    override fun onBindViewHolder(holder: CustomAdapter.ViewHolder, position: Int) {
        holder.bindItems(userList[position])
    }

    override fun getItemCount(): Int = userList.size

    inner class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
            private val textViewName: TextView = itemView.findViewById(R.id.textViewUsername)
            private val textViewAddress: TextView  = itemView.findViewById(R.id.textViewAddress)

        fun bindItems(user: User) = with(itemView) {
            textViewName.text = user.name
            textViewAddress.text = user.address
            setOnClickListener { listener(user) }
        }
    }
}

然后

val adapter = CustomAdapter(userList) { user ->
    // do something with user on click
}
recyclerView.adapter = adapter

Answer 2

好的，让我们分3步完成

1-您使用onClick方法定义一个接口作为回调像这样

        for (DocumentFile file : pickedDir.listFiles()) {
            if (file.isDirectory() && file.getName().equals("Portfolio")) {
                file.createDirectory("Subdirectory");
            }
        }

在适配器中的2-秒在视图持有者中添加一个单击侦听器，并调用这样的接口方法

修改

interface UserClickCallbacks { fun onUserClick(user: User) }

3-在您的活动中，您实施了class CustomAdapter(val userList: ArrayList<User>, private val userClickCallbacks: UserClickCallbacks) : RecyclerView.Adapter<CustomAdapter.ViewHolder>() { //this method is returning the view for each item in the list class MyAdapter(val userList: ArrayList<User>) override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CustomAdapter.ViewHolder { val v = LayoutInflater.from(parent.context).inflate(R.layout.row_layout, parent, false) return ViewHolder(v) } //this method is binding the data on the list override fun onBindViewHolder(holder: CustomAdapter.ViewHolder, position: Int) { holder.textViewName.text = user.name holder.textViewAddress.text = user.address } //this method is giving the size of the list override fun getItemCount(): Int { return userList.size } //the class is hodling the list view class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView), View.OnClickListener { init { view.setOnClickListener(this) } val textViewName = itemView.findViewById(R.id.textViewUsername) val textViewAddress = itemView.findViewById(R.id.textViewAddress) override fun onClick(p0: View?) { userClickCallbacks.onUserClick(userList[adapterPosition]) } } }界面并覆盖像这样的UserClickCallbacks方法

onUserClick()

Answer 3

不要忘记将inner添加到ViewHolder课程，否则您将无法访问位于listener内的Adapter对象：

package com.niel.customview

import android.support.v7.widget.RecyclerView
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.ImageView

/**
 * Created by nileshdeokar on 12/03/2018.
 */
class MediaAdapter(private var mData: ArrayList<String>) : RecyclerView.Adapter<MediaAdapter.ViewHolder>() {

    lateinit var listener: OnItemClickedListener

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

    }

    override fun onBindViewHolder(holder: ViewHolder?, position: Int) {
        val model = mData[position]
    }

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


    inner class ViewHolder : RecyclerView.ViewHolder, View.OnClickListener {
        var imageViewSq: ImageView

        constructor(itemView: View?) : super(itemView) {
            imageViewSq = itemView?.findViewById(R.id.imgSq)!!
            itemView.setOnClickListener(this)
        }

        override fun onClick(p0: View?) {
            listener.onItemClick(adapterPosition)
        }
    }

    fun setOnItemClickedListener(listener: OnItemClickedListener) {
        this.listener = listener
    }

    interface OnItemClickedListener {
        fun onItemClick(position: Int) 
    }

}

如何在kotlin中的customadpter项目上实现clicklistener？

3 个答案: