Android HashMap in Bundle?

Question

The android.os.Message uses a Bundle to send with it\'s sendMessage-method. Therefore, is it possible to put a HashMap inside a

Answer 1

I am using my kotlin implementation of Parcelable to achieve that and so far it works for me. It is useful if you want to avoid the heavy serializable.

Also in order for it to work, I recommend using it with these

Declaration

class ParcelableMap<K,V>(val map: MutableMap<K,V>) : Parcelable {
    constructor(parcel: Parcel) : this(parcel.readMap(LinkedHashMap<K,V>()))

    override fun writeToParcel(parcel: Parcel, flags: Int) {
        parcel.writeMap(map)
    }

    override fun describeContents(): Int {
        return 0
    }

    companion object CREATOR : Parcelable.Creator<ParcelableMap<Any?,Any?>> {
        @JvmStatic
        override fun createFromParcel(parcel: Parcel): ParcelableMap<Any?,Any?> {
            return ParcelableMap(parcel)
        }
        @JvmStatic 
        override fun newArray(size: Int): Array<ParcelableMap<Any?,Any?>?> {
            return arrayOfNulls(size)
        }
    }

}

Use

write

val map = LinkedHashMap<Int, String>()
val wrap = ParcelableMap<Int,String>(map)
Bundle().putParcelable("your_key", wrap)

read

val bundle = fragment.arguments ?: Bundle()
val wrap = bundle.getParcelable<ParcelableMap<Int,String>>("your_key")
val map = wrap.map

Don't forget that if your map K,V are not parceled by default they must implement Parcelable