问可Parcelable不保存变量

EN

data class MyParcelableClass(
    val fieldA: String,
    val fieldB: Int,
    val fieldC: AnotherParcelableClass
) : Parcelable {

    // This is the one I'm having problems with
    var troublesomeVariable: TroublesomeParcelableClass? = null
        set(value) {
            field = value
            if (field != null)
                // do stuff (irrelevant to the question)
        }

    override fun writeToParcel(dest: Parcel?, flags: Int) {
        dest?.run {
            writeString(fieldA)
            writeInt(fieldB)
            writeParcelable(fieldC, flags)
            writeParcelable(troublesomeVariable, flags) 
            /*
             * At this point, troublesomeVariable is null, 
             * even though a value has already been assigned
             */
        }
    }

    override fun describeContents() = 0

    companion object CREATOR : Parcelable.Creator<MyParcelableClass> {
        override fun createFromParcel(source: Parcel): MyParcelableClass {
            val fieldA = source.readString()!!
            val fieldB = source.readInt()
            val fieldC = source.readParcelable<AnotherParcelableClass>(AnotherParcelableClass::class.java.classLoader)!!
            val troublesomeVariable = source.readParcelable<TroublesomeParcelableClass>(TroublesomeParcelableClass::class.java.classLoader)!!
            /*
             * Since troublesomeVariable has been written as null to the parcel,
             * it will obviously be null here as well
             */

            return MyParcelableClass(fieldA, fieldB, fieldC).also {
                it.troublesomeVariable = troublesomeVariable
            }
        }

        override fun newArray(size: Int): Array<MyParcelableClass?> = arrayOfNulls(size)
    }

}