如何在fragment中打开recyclerView上的不同活动?

Question

我使用一个recyclerView来显示我的listtiitems在home片段。但我一直被困在如何打开一个不同的活动时，项目点击。接下来我该怎么做?你能帮我解决这个问题吗?我很感激你的帮助。

HomeFragment.kt

class HomeFragment : Fragment() {
private var _binding: FragmentHomeBinding? = null
private val binding get() = _binding!!
lateinit var recycle1:RecyclerView
private val list = ArrayList<Locations>()
private val adapter:Adapter = Adapter(list)
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
var v =inflater.inflate(R.layout.fragment_home, container, false)
recycle1 = v.findViewById(R.id.rv_item)
recycle1.layoutManager = LinearLayoutManager(activity)
list.clear()
testData()
val adapterr = Adapter(list)
recycle1.adapter = adapterr
adapter.notifyDataSetChanged()
recycle1.setHasFixedSize(true)
return v
}
private fun testData(){
list.add(Locations(R.drawable.book_cafe,"The Book Cafe","20 Martin Rd","Cafe"))
list.add(Locations(R.drawable.citysprouts,"City Sprouts","102 Henderson Road","Cafe"))
list.add(Locations(R.drawable.esplanade,"Library@esplande","8 Raffles Ave","Library"))
list.add(Locations(R.drawable.hf,"Library@Harbourfront","1 HarbourFront Walk","Library"))
list.add(Locations(R.drawable.mangawork,"MangaWork","291 Serangoon Rd","Cafe"))
list.add(Locations(R.drawable.orchard,"Library@orchard","277 Orchard Road","Library"))
list.add(Locations(R.drawable.rabbitandfox,"Rabbit&Fox","160 Orchard Rd","Cafe"))
list.add(Locations(R.drawable.sixlettercoffee,"T6 Letter Coffee","259 Tanjong Katong Rd","Cafe"))
}

}

Adapter.kt

class Adapter (val listItem:ArrayList<Locations>) : RecyclerView.Adapter<Adapter.RecycleViewHolder>(){
inner class RecycleViewHolder(itemView: View):RecyclerView.ViewHolder(itemView){
val itemImage: ShapeableImageView = itemView.findViewById(R.id.item_image)
val heading: TextView = itemView.findViewById(R.id.item_title)
val detail: TextView = itemView.findViewById(R.id.item_detail)
val category: TextView = itemView.findViewById(R.id.item_categories)
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecycleViewHolder {
val view:View = LayoutInflater.from(parent.context).inflate(R.layout.list_item, parent, false)
return RecycleViewHolder(view)
}
override fun getItemCount(): Int {
return listItem.size
}
override fun onBindViewHolder(holder: RecycleViewHolder, position: Int) {
val item = listItem[position]
holder.itemImage.setImageResource(item.itemImage)
holder.heading.text = item.headings
holder.detail.text = item.detail
holder.category.text = item.category
}

位置。kt

data class Locations(var itemImage:Int,var headings :String,var detail :String,var category :String)

Answer 1

你必须借助一个界面来导航:

首先创建一个接口，命名为Navigate

interface Navigate {

fun onRecyclerViewItemClicked(location : Location)
}

那么你必须在适配器和片段中使用这个接口:在适配器中，您必须执行以下操作:

class Adapter (val listItem:ArrayList<Locations>) : RecyclerView.Adapter<Adapter.RecycleViewHolder>(){
//Declare listener object
var listener: Navigate? = null

inner class RecycleViewHolder(itemView: View):RecyclerView.ViewHolder(itemView){
val itemImage: ShapeableImageView = itemView.findViewById(R.id.item_image)
val heading: TextView = itemView.findViewById(R.id.item_title)
val detail: TextView = itemView.findViewById(R.id.item_detail)
val category: TextView = itemView.findViewById(R.id.item_categories)
}
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecycleViewHolder {
val view:View = LayoutInflater.from(parent.context).inflate(R.layout.list_item, parent, false)
return RecycleViewHolder(view)
}
override fun getItemCount(): Int {
return listItem.size
}
override fun onBindViewHolder(holder: RecycleViewHolder, position: Int) {
val item = listItem[position]
holder.itemImage.setImageResource(item.itemImage)
holder.heading.text = item.headings
holder.detail.text = item.detail
holder.category.text = item.category
// Now suppose you want to navigate to another fragment / Activity on click of the itemImage , then do the following 
holder.itemImage.setOnClickListener{

listener?.onRecyclerViewItemClicked(item)
}
}

现在在你的片段中扩展导航类并实现重写方法:

class HomeFragment : Fragment() , Navigate {
// Rest of your code

override fun onRecyclerViewItemClicked(location : Location){
// The argument location here is the information of the item that is clicked of 
// the RecyclerView
// Here write your code to navigate to the next fragment / activity based on what 
//you are using NavController / Fragment Manager
}

}

Answer 2

在视图holder的init{}块中设置一个clickListener例如。

inner class RecycleViewHolder(itemView: View):RecyclerView.ViewHolder(itemView){
val itemImage: ShapeableImageView = itemView.findViewById(R.id.item_image)
val heading: TextView = itemView.findViewById(R.id.item_title)
val detail: TextView = itemView.findViewById(R.id.item_detail)
val category: TextView = itemView.findViewById(R.id.item_categories)

init {
itemView.setOnClickListener { // start your activity using view context  }
}
}

永远不要在onBindViewHolder()方法中设置点击监听器，因为点击监听器会设置多次，因为每次在回收器视图中绑定项目时都会调用此方法方法。参考官方文档