如何在Kotlin中的导航抽屉活动中添加OnFragmentInteractionListener？
我试图做一个应用程序使用导航抽屉活动但我需要使用碎片当我是添加片段，并试图切换片段之间的崩溃我不是为什么它崩溃事务抛出一个错误：
Process: com.a3.aakap.ftrial, PID: 6958 java.lang.RuntimeException: Unable to start activity ComponentInfo{com.a3.aakap.ftrial/com.a3.aakap.ftrial.MainActivity}: java.lang.RuntimeException: com.a3.aakap.ftrial.MainActivity@9483ac4 must implement OnFragmentInteractionListener 而我无法修复它，因为我是新的在这里这是我的MainAcivity.kt文件：
class MainActivity : AppCompatActivity(), NavigationView.OnNavigationItemSelectedListener { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) setSupportActionBar(toolbar) fab.setOnClickListener { view -> Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG).setAction("Action", null).show() } val toggle = ActionBarDrawerToggle(this, drawer_layout, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close) drawer_layout.addDrawerListener(toggle) toggle.syncState() nav_view.setNavigationItemSelectedListener(this) title = "Fragment One" val fragment = FirstFragment() val fragmentTransaction = supportFragmentManager.beginTransaction() fragmentTransaction.replace(R.id.first_activity, fragment, "FragmentOne") //create first framelayout with id fram in the activity where fragments will be displayed fragmentTransaction.commit() } override fun onBackPressed() { if (drawer_layout.isDrawerOpen(GravityCompat.START)) { drawer_layout.closeDrawer(GravityCompat.START) } else { super.onBackPressed() } } override fun onCreateOptionsMenu(menu: Menu): Boolean { // Inflate the menu; this adds items to the action bar if it is present. menuInflater.inflate(R.menu.main, menu) return true } override fun onOptionsItemSelected(item: MenuItem): Boolean { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. when (item.itemId) { R.id.action_settings -> return true else -> return super.onOptionsItemSelected(item) } } override fun onNavigationItemSelected(item: MenuItem): Boolean { // Handle navigation view item clicks here. when (item.itemId) { R.id.first_activity -> { title = "Fragment One" val fragment = FirstFragment() val fragmentTransaction = supportFragmentManager.beginTransaction() fragmentTransaction.replace(R.id.first_activity, fragment, "FragmentOne") //create first framelayout with id fram in the activity where fragments will be displayed fragmentTransaction.commit() // Handle the camera action } R.id.second_activity -> { title = "Fragment Second" val fragment = FirstFragment() val fragmentTransaction = supportFragmentManager.beginTransaction() fragmentTransaction.replace(R.id.second_activity, fragment, "FragmentOne") //create first framelayout with id fram in the activity where fragments will be displayed fragmentTransaction.commit() } R.id.nav_share -> { } R.id.nav_exit -> { System.exit(0) } } drawer_layout.closeDrawer(GravityCompat.START) return true }
}
请帮助我，我试图解决它，但我不能请帮助我
这是我的第一个片段代码：
package com.a3.aakap.ftrial import android.content.Context import android.net.Uri import android.os.Bundle import android.support.v4.app.Fragment import android.view.LayoutInflater import android.view.View import android.view.ViewGroup
/ ** *一个简单的[Fragment]子类。 *包含这个片段的活动必须实现* [FirstFragment.OnFragmentInteractionListener]接口来处理交互事件。 *使用[FirstFragment.newInstance]工厂方法*创建这个片段的一个实例。 * / class FirstFragment：Fragment（）{
// TODO: Rename and change types of parameters private var mParam1: String? = null private var mParam2: String? = null private var mListener: OnFragmentInteractionListener? = null override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) if (arguments != null) { mParam1 = arguments.getString(ARG_PARAM1) mParam2 = arguments.getString(ARG_PARAM2) } } override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?, savedInstanceState: Bundle?): View? { // Inflate the layout for this fragment return inflater!!.inflate(R.layout.fragment_first, container, false) } // TODO: Rename method, update argument and hook method into UI event fun onButtonPressed(uri: Uri) { if (mListener != null) { mListener!!.onFragmentInteraction(uri) } } override fun onAttach(context: Context?) { super.onAttach(context) if (context is OnFragmentInteractionListener) { mListener = context } else { throw RuntimeException(context!!.toString() + " must implement OnFragmentInteractionListener") } } override fun onDetach() { super.onDetach() mListener = null } /** * This interface must be implemented by activities that contain this * fragment to allow an interaction in this fragment to be communicated * to the activity and potentially other fragments contained in that * activity. * * * See the Android Training lesson [Communicating with Other Fragments](http://developer.android.com/training/basics/fragments/communicating.html) for more information. */ interface OnFragmentInteractionListener { // TODO: Update argument type and name fun onFragmentInteraction(uri: Uri) } companion object { // TODO: Rename parameter arguments, choose names that match // the fragment initialization parameters, eg ARG_ITEM_NUMBER private val ARG_PARAM1 = "param1" private val ARG_PARAM2 = "param2" /** * Use this factory method to create a new instance of * this fragment using the provided parameters. * * @param param1 Parameter 1. * @param param2 Parameter 2. * @return A new instance of fragment FirstFragment. */ // TODO: Rename and change types and number of parameters fun newInstance(param1: String, param2: String): FirstFragment { val fragment = FirstFragment() val args = Bundle() args.putString(ARG_PARAM1, param1) args.putString(ARG_PARAM2, param2) fragment.arguments = args return fragment } }
} //必需的空公共con
这是我的Fragement xml：
显然，你正试图通过OnFragmentInteractionListener接口来实现片段和活动之间的通信机制，所以使用
class MainActivity : AppCompatActivity(), FirstFragment.OnFragmentInteractionListener, NavigationView.OnNavigationItemSelectedListener { // .. other code override fun onFragmentInteraction(uri: Uri) { // TODO Implement } }
并覆盖方法