如何在包含 ArrayList<String> 的 class 上实现 Parcelable?

How to implement Parcelable on my class which contains an ArrayList<String>?

我只想知道如何读写ArrayList。我用 Kotlin。

data class CustomerTxn(

    @field:SerializedName("txn_note")
    val txnNote: String? = null,

    @field:SerializedName("txn_date")
    val txnDate: String? = null,

    @field:SerializedName("amount")
    val amount: String? = null,

    @field:SerializedName("txn_type")
    val txnType: String? = null,

    @field:SerializedName("contact")
    val contact: String? = null,

    @field:SerializedName("transaction_images")
    var transactionImages: ArrayList<String>? = null,

    @field:SerializedName("created_at")
    val createdAt: String? = null,

    @field:SerializedName("cashbook")
    val cashbook: String? = null,

    @field:SerializedName("view_type")
    val viewType: String? = null,

    @field:SerializedName("id")
    val id: String? = null,

    @field:SerializedName("modified_at")
    val modifiedAt: String? = null
    ):Parcelable {
        constructor(parcel: Parcel) : this(
        parcel.readString(),
        parcel.readString(),
        parcel.readString(),
        parcel.readString(),
        parcel.readString(),
        parcel.readArrayList(null),
        parcel.readString(),
        parcel.readString(),
        parcel.readString(),
        parcel.readString(),
        parcel.readString()) {
}

override fun writeToParcel(parcel: Parcel, flags: Int) {
    parcel.writeString(txnNote)
    parcel.writeString(txnDate)
    parcel.writeString(amount)
    parcel.writeString(txnType)
    parcel.writeString(contact)
    parcel.writeList(transactionImages)
    parcel.writeString(createdAt)
    parcel.writeString(cashbook)
    parcel.writeString(viewType)
    parcel.writeString(id)
    parcel.writeString(modifiedAt)
}

override fun describeContents(): Int {
    return 0
}

companion object CREATOR : Parcelable.Creator<CustomerTxn> {
    override fun createFromParcel(parcel: Parcel): CustomerTxn {
        return CustomerTxn(parcel)
    }

    override fun newArray(size: Int): Array<CustomerTxn?> {
        return arrayOfNulls(size)
    }
}

这些行给我错误:

parcel.readArrayList(null)
parcel.writeList(transactionImages)

parcel.readArrayList(null) 的错误: 类型不匹配。 Required:ArrayList<字符串>?找到(ArrayList<任何!>?..ArrayList<*>?)

parcel.writeList(transactionImages) 的错误: Java 预期类型不匹配 (Mutable)List<(raw) Any?>!但发现 ArrayList?。使用显式转换

我正在使用 Java 而不是 Kotlin 但我认为这个问题可以通过相同的解决方案来解决。

我经常使用:

  • parcel.createStringArrayList() 而不是 parcel.readArrayList(null)
  • parcel.writeStringList(transactionImages) 而不是 parcel.writeList(transactionImages)

抱歉,OOT,但您可以使用 @Parcelize 创建 Parcelable class:

@Parcelize
data class CustomerTxn(

    @field:SerializedName("txn_note")
    val txnNote: String? = null,

    @field:SerializedName("txn_date")
    val txnDate: String? = null,

    @field:SerializedName("amount")
    val amount: String? = null,

    @field:SerializedName("txn_type")
    val txnType: String? = null,

    @field:SerializedName("contact")
    val contact: String? = null,

    @field:SerializedName("transaction_images")
    var transactionImages: ArrayList<String>? = null,

    @field:SerializedName("created_at")
    val createdAt: String? = null,

    @field:SerializedName("cashbook")
    val cashbook: String? = null,

    @field:SerializedName("view_type")
    val viewType: String? = null,

    @field:SerializedName("id")
    val id: String? = null,

    @field:SerializedName("modified_at")
    val modifiedAt: String? = null
): Parcelable

所以不用担心将 ArrayList<String> 保存到包裹中。