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科特林的SectionedRecyclServiceAdapter

android-recyclerview kotlin android

Best Best · 技术社区 · 7 年前

谁能把java代码重构成kotlin代码?

这是我的密码

食物适应性。kt

class FoodListAdapter: StatelessSection(SectionParameters.builder()
    .itemResourceId(R.layout.content_food_list)
    .headerResourceId(R.layout.header_food_list)
    .build()) {

    val itemList = arrayListOf<Int>(1, 2, 3 ,4)

    override fun getContentItemsTotal(): Int {
        return itemList.size
    }

    override fun onBindItemViewHolder(holder: RecyclerView.ViewHolder?, position: Int) {
        val itemHolder = holder as MyItemViewHolder

        // bind your view here
        itemHolder.tvItem.setText(itemList[position])
    }

    override fun getItemViewHolder(view: View?): RecyclerView.ViewHolder {
        return MyItemViewHolder(view!!)
    }
}

class MyItemViewHolder(itemView: View): RecyclerView.ViewHolder(itemView) {
    lateinit var tvItem: TextView
    init {
        tvItem = itemView.findViewById(R.id.txtItem) as TextView
    }
}

不吃东西。kt

class FoodActivity : AppCompatActivity() {

private var context: Context? = null

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_food_list)

    context = this
    val sectionAdapter = SectionedRecyclerViewAdapter()

// Add your Sections
        sectionAdapter.addSection(FoodListAdapter())

// Set up your RecyclerView with the SectionedRecyclerViewAdapter
        val recyclerView = findViewById(R.id.foodList) as RecyclerView
        recyclerView.setLayoutManager(LinearLayoutManager(context))
        recyclerView.adapter(sectionAdapter)
    }
}

我有个问题是 “无法将类型为'RecyclerView.adapter<(原始)RecyclerView.ViewHolder!>?'的表达式'adapter'作为函数调用。找不到函数'invoke()'” 在recyclerView之后。适配器(部分适配器) 有人请指导我解决这个问题。对不起,我英语不好

0 回复 | 直到 7 年前

Patrik Figura 7 年前

class FoodListAdapter(val itemList): StatelessSection(SectionParameters.builder()
    .itemResourceId(R.layout.content_food_list)
    .headerResourceId(R.layout.header_food_list)
    .build()) {

    override fun getContentItemsTotal(): Int {
        return itemList.size
    }

    override fun onBindItemViewHolder(holder: RecyclerView.ViewHolder, position: Int) {
        val itemHolder = holder as MyItemViewHolder
        itemHolder.tvItem.setText(itemList[position])
    }

    override fun getItemViewHolder(view: View?): RecyclerView.ViewHolder {
        return MyItemViewHolder(view!!)
    }
}

class MyItemViewHolder(itemView: View): RecyclerView.ViewHolder(itemView) {
    internal val tvItem: TextView =itemView.findViewById(R.id.txtItem)
}

对于你的活动,你不需要上下文变量活动扩展上下文

class FoodActivity : AppCompatActivity() {

override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.activity_food_list)

    val sectionAdapter = SectionedRecyclerViewAdapter()

        val itemList = arrayListOf<Int>(1, 2, 3 ,4)
        sectionAdapter.addSection(FoodListAdapter(itemList))

        val recyclerView:RecyclerView = findViewById(R.id.foodList)
        recyclerView.layoutManager = LinearLayoutManager(context)
        recyclerView.adapter = sectionAdapter
    }
}

正如@CampbellMG提到的,您需要使用 recyclerView.adapter = sectionAdapter 或 recyclerView.setAdapter(sectionAdapter)

recyclerView.adapter=sectionAdapter 更地道

CampbellMG 7 年前

您正在尝试将类属性作为函数访问

在Java中,您可以将适配器设置为:

recyclerView.setAdapter(sectionAdapter)

在科特林,这看起来像:

recyclerView.adapter = sectionAdapter

看一看 here 了解更多信息。