如何在活动之间进行切换和保存？(Kotlin)

// 在ActivityA中
val intent = Intent(this, ActivityB::class.java)
startActivity(intent)

// 在ActivityA中
val intent = Intent(this, ActivityB::class.java)
startActivityForResult(intent, REQUEST_CODE)

// 在ActivityB中，当需要返回数据时
val returnIntent = Intent()
returnIntent.putExtra("resultKey", "resultValue")
setResult(Activity.RESULT_OK, returnIntent)
finish()

// 在ActivityA中重写onActivityResult方法
override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
    super.onActivityResult(requestCode, resultCode, data)
    if (requestCode == REQUEST_CODE && resultCode == Activity.RESULT_OK) {
        val result = data?.getStringExtra("resultKey")
        // 使用返回的结果
    }
}

// 从ActivityA向ActivityB传递数据
val intent = Intent(this, ActivityB::class.java)
intent.putExtra("extraKey", "extraValue")
startActivity(intent)

// 在ActivityB中接收数据
val value = intent.getStringExtra("extraKey")

// 保存数据
val sharedPreferences = getSharedPreferences("MySharedPref", Context.MODE_PRIVATE)
val editor = sharedPreferences.edit()
editor.putString("key", "value")
editor.apply()

// 读取数据
val value = sharedPreferences.getString("key", "default_value")