Question

我想使用Kotlin从RecyclerView开始一项新的活动。

我仍在探索Kotlin，目前停留在如何从RecyclerView中打开新活动的地方。

class HomeScreenRecyclerAdapter : RecyclerView.Adapter<HomeScreenRecyclerAdapter.ViewHolder>()
{
    private val titles = arrayOf("About Me",
            "About Me", "About Me", "About Me"
    )
    private val details = arrayOf("Item one details", "Item two details",
            "Item three details", "Item four details")


    private val images = intArrayOf(R.drawable.ic_launcher_background,
            R.drawable.ic_launcher_background, R.drawable.ic_launcher_background,
            R.drawable.ic_launcher_background)

    override fun onCreateViewHolder(viewGroup: ViewGroup, i: Int): ViewHolder {
        val v = LayoutInflater.from(viewGroup.context)
                .inflate(R.layout.main_card_view, viewGroup, false)
        return ViewHolder(v)
    }

    override fun onBindViewHolder(viewHolder: ViewHolder, position: Int) {
        viewHolder.itemTitle.text = titles[position]
        viewHolder.itemDetail.text = details[position]
        viewHolder.itemImage.setImageResource(images[position])
    }

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

    inner class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        val intent: Intent? = null
        var itemImage: ImageView
        var itemTitle: TextView
        var itemDetail: TextView
        init {
            itemImage = itemView.findViewById(R.id.main_image_view)
            itemTitle = itemView.findViewById(R.id.main_title_view)
            itemDetail = itemView.findViewById(R.id.main_description_view)

            itemView.setOnClickListener { 

            }
        }
    }
}

我只是想不出如何为RecyclerView中的每个项目启动一个新活动。我知道我正在使事情变得更复杂。

Answer 1

只需尝试以下解决方案：首先，在您的适配器中，将监听器写入您的recyclerview项目：

class HomeScreenRecyclerAdapter(val data: ArrayList<Data>) : RecyclerView.Adapter<ContactAdapter.ViewHolder>() {
private var listener: ((Data) -> Unit)? = null
...

fun setOnItemClickListener(f: (Data) -> Unit) {
     listener = f
}

在init里面：

 itemView.setOnClickListener {
      listener?.invoke(data[adapterPosition])
 }

最后，在“活动”中，您可以使用手柄项clickListeners：


private val data = ArrayList<Data>()
val adapter = HomeScreenRecyclerAdapter(data)

 adapter.setOnItemClickListener {
    when(it){
      1->{startActivity(Intent(context, YourActivity1::class.java))}
      2->{startActivity(Intent(context, YourActivity2::class.java))}
      ...
      else->{}
    }
 }

数据是您商品的模型类。仅此而已，希望对您有所帮助！

Answer 2

只需在ViewHolder itemOnClick方法内启动活动，如下所示。并且您需要传递适配器活动的上下文引用。

class HomeScreenRecyclerAdapter(var mContext:Context) : RecyclerView.Adapter<HomeScreenRecyclerAdapter.ViewHolder>()
{
    private val titles = arrayOf("About Me",
        "About Me", "About Me", "About Me")

    private val details = arrayOf("Item one details", "Item two details",
        "Item three details", "Item four details")


    private val images = intArrayOf(R.drawable.ic_launcher_background,
        R.drawable.ic_launcher_background, R.drawable.ic_launcher_background,
        R.drawable.ic_launcher_background)

    override fun onCreateViewHolder(viewGroup: ViewGroup, i: Int): ViewHolder {
       val v = LayoutInflater.from(viewGroup.context)
            .inflate(R.layout.main_card_view, viewGroup, false)
       return ViewHolder(v)
    }

    override fun onBindViewHolder(viewHolder: ViewHolder, position: Int) {
       viewHolder.itemTitle.text = titles[position]
       viewHolder.itemDetail.text = details[position]
       viewHolder.itemImage.setImageResource(images[position])
    }

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

   inner class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
      val intent: Intent? = null
      var itemImage: ImageView
      var itemTitle: TextView
      var itemDetail: TextView
     init {
        itemImage = itemView.findViewById(R.id.main_image_view)
        itemTitle = itemView.findViewById(R.id.main_title_view)
        itemDetail = itemView.findViewById(R.id.main_description_view)

        itemView.setOnClickListener { 
             mContext.startActivity(Intent(mContext, ActivityNameWhichYouWantCall::class.java))
        }
    }
  }
}

Answer 3

只需使用此：

context.startActivity(Intent(context, Activity::class.java))

Kotlin RecyclerView开始新活动

3 个答案: