Estoy intentando empezar con ViewPager和Android con Kotlin。 很有可能是Tengo tres碎片，是ViewPagers上的货物，是没有碎片的punedo acceder，在los textview para cambiar su valor中也没有。
esto es el片段：
package com.example.jose.juegopreguntas
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
import com.example.juegopreguntas.R
import kotlinx.android.synthetic.main.fragment_responder_pregunta.*
/**
* A simple [Fragment] subclass.
* Activities that contain this fragment must implement the
* [ResponderPregunta.OnFragmentInteractionListener] interface
* to handle interaction events.
* Use the [ResponderPregunta.newInstance] factory method to
* create an instance of this fragment.
*
*/
class ResponderPregunta : Fragment() {
// TODO: Rename and change types of parameters
private var listener: OnFragmentInteractionListener? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
}
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?): View? {
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_responder_pregunta, container, false)
}
// TODO: Rename method, update argument and hook method into UI event
fun onButtonPressed(uri: Uri) {
listener?.onFragmentInteraction(uri)
}
override fun onAttach(context: Context) {
super.onAttach(context)
if (context is OnFragmentInteractionListener) {
listener = context
} else {
throw RuntimeException(context.toString() + " must implement OnFragmentInteractionListener")
}
}
override fun onDetach() {
super.onDetach()
listener = 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 {
/**
* 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 ResponderPregunta.
*/
// TODO: Rename and change types and number of parameters
@JvmStatic
fun newInstance() =
ResponderPregunta().apply {
}
}
}
目前的活动：
class VistaUsuario : AppCompatActivity() ,
recibir_preguntas.OnFragmentInteractionListener ,
enviar_preguntas.OnFragmentInteractionListener ,
ResponderPregunta.OnFragmentInteractionListener {
override fun onFragmentInteraction(uri: Uri) {
TODO("not implemented") //To change body of created functions use
File | Settings | File Templates.
}
/**
* The [android.support.v4.view.PagerAdapter] that will provide
* fragments for each of the sections. We use a
* {@link FragmentPagerAdapter} derivative, which will keep every
* loaded fragment in memory. If this becomes too memory intensive,
它 *最好切换到 * [android.support.v4.app.FragmentStatePagerAdapter]。 * / 私人var mSectionsPagerAdapter：SectionsPagerAdapter？ =空
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_vista_usuario)
setSupportActionBar(toolbar)
// Create the adapter that will return a fragment for each of the three
// primary sections of the activity.
mSectionsPagerAdapter = SectionsPagerAdapter(supportFragmentManager)
// Set up the ViewPager with the sections adapter.
container.adapter = mSectionsPagerAdapter
container.addOnPageChangeListener(TabLayout.TabLayoutOnPageChangeListener(tabs))
tabs.addOnTabSelectedListener(TabLayout.ViewPagerOnTabSelectedListener(container))
fab.setOnClickListener { view ->
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show()
}
}
override fun onCreateOptionsMenu(menu: Menu): Boolean {
// Inflate the menu; this adds items to the action bar if it is present.
menuInflater.inflate(R.menu.menu_vista_usuario, 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.
val id = item.itemId
if (id == R.id.action_settings) {
return true
}
return super.onOptionsItemSelected(item)
}
/**
* A [FragmentPagerAdapter] that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
inner class SectionsPagerAdapter(fm: FragmentManager) : FragmentPagerAdapter(fm) {
override fun getItem(position: Int): Fragment {
// getItem is called to instantiate the fragment for the given page.
// Return a PlaceholderFragment (defined as a static inner class below).
return PlaceholderFragment.newInstance(position + 1)
}
override fun getCount(): Int {
// Show 3 total pages.
return 3
}
}
/**
* A placeholder fragment containing a simple view.
*/
class PlaceholderFragment : Fragment() {
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?): View? {
val rootView = inflater.inflate(R.layout.fragment_vista_usuario, container, false)
rootView.section_label.text = getString(R.string.section_format, arguments?.getInt(ARG_SECTION_NUMBER))
return rootView
}
companion object {
/**
* The fragment argument representing the section number for this
* fragment.
*/
private val ARG_SECTION_NUMBER = "section_number"
/**
* Returns a new instance of this fragment for the given section
* number.
*/
fun newInstance(sectionNumber: Int): Fragment {
lateinit var fragment : Fragment
when(sectionNumber){
1 -> fragment = recibir_preguntas.newInstance()
2 -> fragment = ResponderPregunta.newInstance()
3 -> fragment = enviar_preguntas.newInstance()
}
val args = Bundle()
args.putInt(ARG_SECTION_NUMBER, sectionNumber)
return fragment
}
}
}
}