Android Kotlin-4 Intent換頁與Parcelize模型

1.Intent換頁
2.Parcelize模組
3.Intent搭配Parcelize模組

1. Intent換頁

    val intent = Intent(this, SecondActivity::class.java)
    startActivity(intent)
    finish()//關掉當前頁面
   

2. Parcelize模組，Kotlin版本在1.1.4以上皆已支援
   以前尚未支援的時候，需要這樣寫

   class User(var name: String?, var info: String?): Parcelable {
        constructor(parcel: Parcel): this(
        parcel.readString()
        ,parcel.readString())
   
        override fun describeContents(): Int {
            return 0
        }
   
        override fun writeToParcel(dest: Parcel?, flags: Int) {
            dest?.writeString(name)
            dest?.writeString(info)
        }
   
        companion object CREATOR: Parcelable.Creator<User> {
            override fun createFromParcel(source: Parcel): User {
                return User(source)
            }
   
            override fun newArray(size: Int): Array<User?> {
                return arrayOfNulls(size)
            }
        }
    }
   

   現在支援後，只需這樣寫

    @Parcelize
    class User(var name: String?, var info: String?): Parcelable {
   
    }
   

3. Intent搭配Parcelize模組

    //按下button傳入Parcelize模組，並換頁
    button.setOnClickListener {
        val appleUser = User("Apple", "A1")
        val javaUser = User("Java", "B1")
        val kotlinUser = User("Kotlin", "C1")
        val intent = Intent(this, SecondActivity::class.java)
        intent.putExtra("user", arrayListOf(appleUser, javaUser, kotlinUser))
        startActivity(intent)
        finish()
    }
    //在onCreate的地方，將Parcelize模組的資料讀出來
    val user = intent.getParcelableArrayListExtra<MainActivity.User>("user")
   
    user?.run {
        indices.forEach {
            println("name ${user[it].name}  info ${user[it].info}")
        }
    }