【发布时间】：2020-12-08 16:26:23
【问题描述】：
我想知道如何使用 LiveData 将数据从一个片段传递到另一个片段
我有这段代码并做了一些我知道但它不起作用的事情请帮助...
这是我的第一个片段
enter code here
类 ItemDetailsfragment : Fragment() { lateinit var viewmodel: ViewModelPassItem
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val view = inflater.inflate(R.layout.details_items_page, container, false)
val title = arguments?.getString("title")
view.title_details_item.text = title
val price = arguments?.getString("price")
view.price_item_details.text = price
val image = arguments?.getString("image")
Picasso.get().load(image).into(view.image_items_detail)
return view
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
viewmodel = ViewModelProviders.of(activity!!).get(ViewModelPassItem::class.java)
val title: TextView = view.findViewById(R.id.title_details_item)
view.plus_icon_item_details.setOnClickListener {
viewmodel.passdata(title.text.toString())
val myfragment = Cart_Fragment()
}
}
}
这是第二个片段
enter code here
类 Cart_Fragment : Fragment() {
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View? {
val viewitem = inflater.inflate(R.layout.cart_fragment, container, false)
val choosebtn: Button = viewitem.findViewById(R.id.choose_titme_and_submit_order_btn)
choosebtn.visibility = View.GONE
val rl_cart = viewitem.findViewById<RecyclerView>(R.id.recycler_view_cart)
rl_cart.visibility = View.GONE
val navbar: BottomNavigationView = activity!!.findViewById(R.id.nav_view_bottom_main)
navbar.visibility = View.GONE
val homeicon: ImageButton = viewitem.home_icon_cart
homeicon.setOnClickListener {
activity?.let {
val intent = Intent(requireContext(), HomeActivity::class.java)
it.startActivity(intent)
}
}
viewitem.start_shopping_in_cart.setOnClickListener {
activity?.let {
val intent = Intent(requireContext(), HomeActivity::class.java)
it.startActivity(intent)
}
}
return viewitem
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
val viewmodel = ViewModelProviders.of(activity!!).get(ViewModelPassItem::class.java)
viewmodel.pass.observe(activity!!, Observer {
d("main", "${it.toString()}")
})
}
}
这是我的 ViewModel 类
enter code here
类 ViewModelPassItem:ViewModel() {
val pass = MutableLiveData<String>()
fun passdata (title : String) {
pass.postValue(title)
} }
好的
当我点击 btn 来获取我传递的字符串时，什么也没发生...
【问题讨论】：
标签： android kotlin android-fragments