I have this problem here:
FATAL EXCEPTION: main Process: com.mytest.app, PID: 20586
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.mytest.app/com.mytest.app.activities.home.HomeActivity}: android.app.Fragment$InstantiationException: Unable to instantiate fragment
com.mytest.app.activities.fragments.MyFragment: make sure class name exists, is public, and has an empty constructor that is public
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2371)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2423)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1342)
at android.os.Handler.dispatchMessage(Handler.java:110)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:5327)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:824)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:640)
at dalvik.system.NativeStart.main(Native Method)
Caused by: android.app.Fragment$InstantiationException: Unable to instantiate fragment com.mytest.app.activities.fragments.MyFragment: make sure class name exists, is public, and has an empty constructor that is public
at android.app.Fragment.instantiate(Fragment.java:605)
at android.app.FragmentState.instantiate(Fragment.java:98)
at android.app.FragmentManagerImpl.restoreAllState(FragmentManager.java:1759)
at android.app.Activity.onCreate(Activity.java:903)
at android.support.v4.app.FragmentActivity.onCreate(FragmentActivity.java:277)
at android.support.v7.app.AppCompatActivity.onCreate(AppCompatActivity.java:84)
at com.mytest.app.activities.MyActivity.onCreate(MyActivity.java:26)
at com.mytest.app.activities.home.HomeActivity.onCreate(HomeActivity.kt:83)
at android.app.Activity.performCreate(Activity.java:5343)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1088)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2331)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2423)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1342)
at android.os.Handler.dispatchMessage(Handler.java:110)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:5327)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:824)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:640)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.IllegalAccessException: access to constructor not allowed
at java.lang.Class.newInstanceImpl(Native Method)
at java.lang.Class.newInstance(Class.java:1215)
at android.app.Fragment.instantiate(Fragment.java:590)
at android.app.FragmentState.instantiate(Fragment.java:98)
at android.app.FragmentManagerImpl.restoreAllState(FragmentManager.java:1759)
I tried to change my Kotlin Object to class using CompanionObject with a static constructor but i have the same result.
The problem is randomized when we are on another application and we want to come back to our app.
Any help?
Thanks.
------EDIT------ Here is my kotlin Object code:
object MyFragment : Fragment() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
}
override fun onResume() {
super.onResume()
}
override fun onDestroy() {
super.onDestroy()
}
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
return inflater.inflate(R.layout.fragment_myfragment, container, false)
}
override fun onViewCreated(view: View?, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
}
override fun onCreateOptionsMenu(menu: Menu, inflater: MenuInflater) {
inflater.inflate(R.menu.mymenu, menu)
}
override fun onOptionsItemSelected(item: MenuItem): Boolean {
// handle item selection
when (item.itemId) {
R.id.action_my_results -> {
return true
}
else -> return super.onOptionsItemSelected(item)
}
}
override fun onAttach(context: Context) {
super.onAttach(context)
}
override fun onDetach() {
super.onDetach()
}}
When you are using object keyword, you make constructor to private then android cannot recreate your fragment. My workaround is :
class MyFragment : Fragment() {
companion object {
@JvmStatic val fragment = MyFragment()
}
// rest or your code
}