13.12 保存到 Realm 中

新增待办事项，存入Realm数据库：

private fun createTodoFrom(title: EditText, todoContent: EditText) {
    realm.beginTransaction()
    // Either update the edited object or create a new one.
    var t = todo ?: realm.createObject(Todo::class.java)
    t.id = todo?.id ?: UUID.randomUUID().toString()
    t.title = title.text.toString()
    t.content = todoContent.text.toString()
    realm.commitTransaction()
    activity.supportFragmentManager.popBackStack()
}