Question

我正在尝试制作一个使用导航抽屉活动的应用但我需要使用片段当我添加片段，并试图在片段之间切换它崩溃我不知道为什么它崩溃事务它抛出错误：

 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

我无法解决这个问题，因为我是新手。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，我已经尝试修复它，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。 *包含此片段的活动必须实现 * [FirstFragment.OnFragmentInteractionListener]界面 *处理交互事件。 *使用[FirstFragment.newInstance]工厂方法 *创建此片段的实例。 * / 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, e.g. 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
    }
}

} //必需的空公共连接

这是我的Fragement xml：

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.a3.aakap.ftrial.FirstFragment">

<!-- TODO: Update blank fragment layout -->
<TextView
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:text="@string/hello_blank_fragment" />
</FrameLayout>

Answer 1

显然，您正试图通过OnFragmentInteractionListener接口实现片段和活动之间的通信机制，因此请使用

class MainActivity : AppCompatActivity(),
       FirstFragment.OnFragmentInteractionListener,
       NavigationView.OnNavigationItemSelectedListener {
     // .. other code

     override fun onFragmentInteraction(uri: Uri) {
      // TODO Implement
     }


}

并覆盖方法

如何在Kotlin中的Navigation Drawer Activity中添加OnFragmentInteractionListener？

1 个答案: