如何在 kotlin 中实现 List<data class>（子列表）的 parcelable？

Posted 2023-04-19

【中文标题】如何在 kotlin 中实现 List<data class>（子列表）的 parcelable？

【英文标题】：How to implementation parcelable for List<data class> (child list) in kotlin?

【发布时间】：2020-12-31 19:44:51

【问题描述】：

我想用 parcelable 将数据类意图用于其他活动。但是当我想打算使用变量类型列表时，我卡住了。我不知道如何实现，因为这是我第一次使用 parcelable

这是我的 POJO/模型

@Parcelize
data class HistoryTree(
val id: Int,
val landOwner: String,
val treeNumber: String,
val membershipId: String,
val speciesId: Int,
val speciesName: String,
val diameter: Double,
val areaName: String,
val woodProducts: List<HistoryProduct>) :Parcelable

@Parcelize
data class HistoryProduct(
val id: Int,
val treeId: Int,
val logStatus: Int,
val orderId: Int,
val logSequenceNumber: Int,
val logNumber: String,
val diameter: String,
val length: String,
val circumference: String,
val logType: Int,
val statusPecah: Int?,
val lubangGerek: Int?,
val pinhole: Int?,
val belimbing: Int?,
val createdBy: Int,
val deleted: Int,
val isTake: Int,
val rejectStatusPetani: Int
) : Parcelable

这是我的活动

package com.sobi.penebangan.historylist
class HistoryListActivity : AppCompatActivity(), CoroutineScope 
private lateinit var job: Job
override val coroutineContext: CoroutineContext
    get() = Dispatchers.Main + job

@Inject
lateinit var viewModelFactory: ViewModelProvider.Factory

private val vm: HistoryListViewModel by lazy  ViewModelProviders.of(this, viewModelFactory).get(HistoryListViewModel::class.java) 

private var trees = mutableListOf<HistoryTree>()

private val treeAdapter = object : RecyclerView.Adapter<HistoryItemViewHolder>() 
    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): HistoryItemViewHolder 
        val ui = HistoryItemUi()
        val view = ui.createView(AnkoContext.create(parent.context, parent))
        return HistoryItemViewHolder(ui, view)
    

    override fun getItemCount(): Int = trees.size



    override fun onBindViewHolder(holder: HistoryItemViewHolder, position: Int) 
        holder.bind(trees[position]) 
            val product = it.woodProducts
            val activity = Intent(this@HistoryListActivity, ProductHistoryListActivity::class.java)
            activity.putExtra(ProductHistoryListActivity.paramTreeNumber, it.treeNumber)
            activity.putExtra(ProductHistoryListActivity.paramHistoryData, it.woodProducts)
            startActivity(activity)

        
    

当我想要使用变量 woodProduct 时出现错误，因为类型数据是 List

谁能帮帮我？

【问题讨论】：

***.com/a/50152749/4168607

谢谢你。我会试试的

【参考方案1】：

在第一个活动中，同时将列表数据添加到意图转换为ArrayList<out Parcelable>

例如：

intent.putParcelableArrayListExtra("arrayList",it.woodProducts as 
ArrayList<out Parcelable>)

然后在第二个活动中获取数据时将其转换为 ArrayList

例如：

    val list =  intent.extras
    val prodList: List<HistoryProduct> = list?.get("arrayList") as ArrayList<HistoryProduct>