I'm building an app like WhatsApp using 3 tabs and every tab have a Fragment. In my first Fragment I have a RecyclerView.
Win a set the SectionsPagerAdapter to start width the RecyclerView Fragment like this:
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)
when(position){
0 -> return Fragmenttask.newInstance()
1 -> return FragmentChat.newInstance()
2 -> return FragmentMaps.newInstance()
else -> {
return null!!
}
}
}
override fun getCount(): Int {
// Show 3 total pages.
return 3
}
}
It give me this error:
E/AndroidRuntime: FATAL EXCEPTION: main Process: com.deraah.mohamed.deraahpro, PID: 21993 java.lang.IllegalStateException: The specified child already has a parent. You must call removeView() on the child's parent first. at android.view.ViewGroup.addViewInner(ViewGroup.java:4937) at android.view.ViewGroup.addView(ViewGroup.java:4768) at android.support.v4.view.ViewPager.addView(ViewPager.java:1477) at android.view.ViewGroup.addView(ViewGroup.java:4708) at android.view.ViewGroup.addView(ViewGroup.java:4681) at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1425) at android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState(FragmentManager.java:1740) at android.support.v4.app.BackStackRecord.executeOps(BackStackRecord.java:794) at android.support.v4.app.FragmentManagerImpl.executeOps(FragmentManager.java:2580) at android.support.v4.app.FragmentManagerImpl.executeOpsTogether(FragmentManager.java:2367) at android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute(FragmentManager.java:2322) at android.support.v4.app.FragmentManagerImpl.execSingleAction(FragmentManager.java:2199) at android.support.v4.app.BackStackRecord.commitNowAllowingStateLoss(BackStackRecord.java:651) at android.support.v4.app.FragmentPagerAdapter.finishUpdate(FragmentPagerAdapter.java:145) at android.support.v4.view.ViewPager.populate(ViewPager.java:1236) at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:662) at android.support.v4.view.ViewPager.setCurrentItemInternal(ViewPager.java:624) at android.support.v4.view.ViewPager.setCurrentItem(ViewPager.java:605) at android.support.design.widget.TabLayout$ViewPagerOnTabSelectedListener.onTabSelected(TabLayout.java:2170) at android.support.design.widget.TabLayout.dispatchTabSelected(TabLayout.java:1165) at android.support.design.widget.TabLayout.selectTab(TabLayout.java:1158) at android.support.design.widget.TabLayout.selectTab(TabLayout.java:1128) at android.support.design.widget.TabLayout$Tab.select(TabLayout.java:1427) at android.support.design.widget.TabLayout$TabView.performClick(TabLayout.java:1537) at android.view.View$PerformClick.run(View.java:24770) at android.os.Handler.handleCallback(Handler.java:790) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:164) at android.app.ActivityThread.main(ActivityThread.java:6494) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)
UPDATE
My fragments:
FragmentChat:
/**
* A simple [Fragment] subclass.
* Activities that contain this fragment must implement the
* [FragmentChat.OnFragmentInteractionListener] interface
* to handle interaction events.
* Use the [FragmentChat.newInstance] factory method to
* create an instance of this fragment.
*/
class FragmentChat : Fragment() {
private var mListener: 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_fragment_chat, 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)
}
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 and change types and number of parameters
fun newInstance(): FragmentChat {
val fragment = FragmentChat()
val args = Bundle()
fragment.arguments = args
return fragment
}
}
}// Required empty public constructor
FragmentMaps:
/**
* A simple [Fragment] subclass.
* Activities that contain this fragment must implement the
* [FragmentMaps.OnFragmentInteractionListener] interface
* to handle interaction events.
* Use the [FragmentMaps.newInstance] factory method to
* create an instance of this fragment.
*/
class FragmentMaps : Fragment() {
private var mListener: 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_fragment_maps, 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 onDetach() {
super.onDetach()
mListener = null
}
interface OnFragmentInteractionListener {
// TODO: Update argument type and name
fun onFragmentInteraction(uri: Uri)
}
companion object {
// TODO: Rename and change types and number of parameters
fun newInstance(): FragmentMaps {
val fragment = FragmentMaps()
val args = Bundle()
fragment.arguments = args
return fragment
}
}
}// Required empty public constructor
Fragmenttask :
class Fragmenttask : Fragment() {
private var mListener: OnFragmentInteractionListener? = null
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
}
override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?,
savedInstanceState: Bundle?): View? {
val CustumViewtask = inflater!!.inflate(R.layout.fragment_fragmenttask, container, false)
val taskMainRV = CustumViewtask.findViewById(R.id.recyclerView_main) as RecyclerView
//taskMainRV.setBackgroundColor(Color.BLUE)
taskMainRV.layoutManager = LinearLayoutManager(context)
//recyclerView_main.adapter = MainAdapter()
fetchJson(taskMainRV)
return taskMainRV
}
fun fetchJson(RSV: RecyclerView) {
//SharedPreferences
val MY_APP_INFO: String = "UserInfo"
val prefs = activity.getSharedPreferences(MY_APP_INFO, AppCompatActivity.MODE_PRIVATE)
val LoggedUserId = prefs.getString("UserId", null)
println("your code is : $LoggedUserId")
println("Attempting to Fetch JSON")
val url = "http://Restful.com/get_tasks.php"
val client = OkHttpClient()
val formBody = FormBody.Builder().add("UserId", LoggedUserId).build()
val request = Request.Builder().url(url)
.post(formBody)
.build()
client.newCall(request).enqueue(object: Callback {
override fun onResponse(call: Call?, response: Response?) {
val body = response?.body()?.string()
println("mohamed : $body")
val gson = GsonBuilder().create()
val tasksfeed = gson.fromJson(body, M_tasksFeed::class.java)
activity.runOnUiThread {
RSV.adapter = MainAdaptertasks(tasksfeed)
}
}
override fun onFailure(call: Call?, e: IOException?) {
println("Failed to execute request")
}
})
}
// TODO: Rename method, update argument and hook method into UI event
fun onButtonPressed(uri: Uri) {
if (mListener != null) {
mListener!!.onFragmentInteraction(uri)
}
}
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 {
fun newInstance(): Fragmenttask {
val fragment = Fragmenttask()
val args = Bundle()
fragment.arguments = args
return fragment
}
}
}// Required empty public constructor
