小编Kar*_*yan的帖子

我有一个显示数据的 Recyclerview 活动。现在我想更新我RecyclerView曾经获得的新数据。现在每次关闭并重新打开我的应用程序时，都会显示新数据。但我希望它无需关闭即可更新我的视图。

我试过这个，

但没有任何效果，

fun setupViewPager(viewPager: ViewPager, it: List<TransactionEntity>, incoming: TransactionAdapterDirection, mainActivity: MainActivity) {

        val cc: Context = mainActivity.applicationContext

        if(adapter.count < 2) {
            if (incoming.equals(OUTGOING)) {
                val gson = Gson()
                val gson1 = GsonBuilder().create()
                val model = it
                val IT = gson.toJson(model)

                val pref = cc.applicationContext.getSharedPreferences("MyPrefSend", 0)
                val editor = pref.edit()
                editor.putString("NEWIT_SEND", IT)
                editor.apply()

                adapter.addFragment(SendingFragment(),"SEND")
                adapter.notifyDataSetChanged()
            } else if (incoming.equals(INCOMING)) {
                val gson = Gson()
                val gson1 = GsonBuilder().create()
                val model = it
                val IT = gson.toJson(model) …

我正在Android使用 Kotlin开发应用程序。在我的应用程序中Tab，ViewPager我实现了两个选项卡。当我移动到另一个活动并压缩到选项卡视图活动时，应用程序停止并logcat显示在错误下方。

java.lang.RuntimeException：无法启动活动 ComponentInfo{com.crypto.wallet/com.crypto.wallet.activities.MainActivity}：android.support.v4.app.Fragment$InstantiationException：无法实例化片段 com.crypto.wallet .activities.ReceiveFragment：找不到片段构造函数

我的片段.kt

@SuppressLint("ValidFragment")
class ReceiveFragment(private val transactionList: List<TransactionEntity>, val appDatabase: AppDatabase, private val direction: TransactionAdapterDirection,
                      val networkDefinitionProvider: NetworkDefinitionProvider) : Fragment(){

    private var linearLayoutManager: LinearLayoutManager? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

    }

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {

        val rootView = inflater.inflate(R.layout.receive_fragment, container, false)
        val recyclerView = rootView.findViewById<RecyclerView>(R.id.transaction_recycler_in) as RecyclerView
        linearLayoutManager = LinearLayoutManager(getActivity(), LinearLayout.VERTICAL, false)
        recyclerView.layoutManager = linearLayoutManager
        recyclerView.adapter = TransactionRecyclerAdapter(transactionList,appDatabase,direction,networkDefinitionProvider)
        recyclerView.setHasFixedSize(true); …