如何在 kotlin android studio 中采用 arraylist 参数在回收器适配器中创建辅助构造函数

Question

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我正在尝试在 recyclerView 适配器中创建其他构造函数但出现错误 请告诉我如何在回收器适配器中创建辅助构造函数，在 kotlin android studio

中采用 arraylist 参数

class CustomRecyclerAdapter constructor(
    val context1: Context,
    val topics: Array<String>,
    private var alist: ArrayList<Array<String>>
) : RecyclerView.Adapter<CustomRecyclerAdapter.ViewHolder>() {

    constructor(sss: ArrayList<Array<String>>, ttt: Array<String>) : this(sss) {
        this.alist = sss
    }

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

    }

    override fun onBindViewHolder(holder: CustomRecyclerAdapter.ViewHolder, position: Int) {
        holder.topicTextView.text = topics[position]
    }

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

    inner class ViewHolder(itemView: View) : RecyclerView.ViewHolder(itemView) {
        var topicTextView: TextView = itemView.findViewById(R.id.gir_topics_tvid)


    }

}

Answer 1

请使用这些构造函数：

class CustomRecyclerAdapter constructor(
    val context: Context, 
    val topics: Array<String> = emptyArray(),
    private var alist: ArrayList<String> 
 ) : RecyclerView.Adapter<CustomRecyclerAdapter.ViewHolder>() {

    constructor(context: Context, sss: ArrayList<String>) : this(context, alist = sss) 

    // ...
}

在主构造函数中，您需要为 topics 指定一个默认值。也给副构造函数加上context: Context参数，在调用主构造函数时传给this()