I am working on a kotlin application that contains fragments. I am converting an app I created using activity to fragments but I am having an issue. I get an error when running the app that the property fragmentHomeBinding has not been initialized and the app closes.
Here's the fragment Home.kt
class Home : Fragment() {
private lateinit var fusedLocationProviderClient: FusedLocationProviderClient
private lateinit var fragmentHomeBinding: FragmentHomeBinding
@SuppressLint("WrongViewCast")
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
getCurrentLocation()
fragmentHomeBinding.etGetCityName.setOnEditorActionListener { v, actionId, keyEvent ->
if(actionId == EditorInfo.IME_ACTION_SEARCH)
{
getCityWeather(fragmentHomeBinding.etGetCityName.text.toString())
val view = activity?.currentFocus
if(view!=null)
{
val imm:InputMethodManager=
activity?.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
imm.hideSoftInputFromWindow(view.windowToken, 0)
fragmentHomeBinding.etGetCityName.clearFocus()
}
true
}
else false
}
}
private fun getCityWeather(cityName:String)
{
fragmentHomeBinding.pbLoading.visibility = View.VISIBLE
ApiUtilities.getApiInterface()?.getCityWeatherData(cityName, API_KEY)?.enqueue(
object:Callback<ModelClass>{
override fun onResponse(call: Call<ModelClass>, response: Response<ModelClass>) {
setDataOnViews((response.body()))
}
override fun onFailure(call: Call<ModelClass>, t: Throwable) {
Toast.makeText(activity?.applicationContext, "Wrong City", Toast.LENGTH_SHORT).show()
}
})
}
private fun getCurrentLocation()
{
if(checkPermission())
{
if(isLocationEnabled())
{
if(ActivityCompat.checkSelfPermission(
requireActivity(), android.Manifest.permission.ACCESS_FINE_LOCATION
) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(
requireActivity(),
android.Manifest.permission.ACCESS_COARSE_LOCATION
) != PackageManager.PERMISSION_GRANTED
){
requestPermission()
return
}
fusedLocationProviderClient.lastLocation.addOnCompleteListener(requireActivity()){ task->
val location: Location?=task.result
if(location==null)
{
fetchCurrentLocationWeather(23.76137119142536.toString(), 90.35059989467042.toString())
}
else
{
fetchCurrentLocationWeather(location.latitude.toString(),location.longitude.toString())
}
}
}
else
{
Toast.makeText(activity?.applicationContext, "Turn on Location", Toast.LENGTH_SHORT).show()
val intent = Intent(Settings.ACTION_LOCATION_SOURCE_SETTINGS)
startActivity(intent)
}
}
}
private fun fetchCurrentLocationWeather(latitude: String, longitude:String)
{
fragmentHomeBinding.pbLoading.visibility = View.VISIBLE
ApiUtilities.getApiInterface()?.getCurrentWeatherData(latitude, longitude, API_KEY)?.enqueue(
object : Callback<ModelClass> {
override fun onResponse(call: Call<ModelClass>, response: Response<ModelClass>) {
if(response.isSuccessful)
{
setDataOnViews(response.body())
}
}
override fun onFailure(call: Call<ModelClass>, t: Throwable) {
Toast.makeText(activity?.applicationContext, "ERROR", Toast.LENGTH_SHORT).show()
}
})
}
private fun setDataOnViews(body: ModelClass?) {
val sdf = SimpleDateFormat("dd/MM/yyyy hh:mm")
val currentDate = sdf.format(Date())
fragmentHomeBinding.tvDateTime.text = currentDate
fragmentHomeBinding.tvDayMaxTemp.text = "" kelvinToCelsius(body!!.main.temp_max) "°"
fragmentHomeBinding.tvDayMinTemp.text = "" kelvinToCelsius(body!!.main.temp_min) "°"
fragmentHomeBinding.tvTemp.text = "" kelvinToCelsius(body!!.main.temp)
fragmentHomeBinding.tvFeelsLike.text = "Feels like: " kelvinToCelsius(body!!.main.feels_like) "°"
fragmentHomeBinding.tvWeatherType.text = body.weather[0].main
fragmentHomeBinding.tvPressure.text = body.main.pressure.toString()
fragmentHomeBinding.tvHumidity.text = body.main.humidity.toString() " %"
fragmentHomeBinding.tvWindSpeed.text = body.wind.speed.toString() " m/s"
fragmentHomeBinding.tvCityName.text = body.name
updateUI(body.weather[0].id)
}
private fun updateUI(id: Int) {
fragmentHomeBinding.pbLoading.visibility = View.GONE
fragmentHomeBinding.mainLayout.visibility = View.VISIBLE
}
private fun kelvinToCelsius(temp: Double): Double
{
var intTemp = temp
intTemp = intTemp.minus(273)
return intTemp.toBigDecimal().setScale(1, RoundingMode.UP).toDouble()
}
companion object
{
const val PERMISSION_REQUEST_ACCESS_LOCATION = 100
const val API_KEY = "3c709ccaf2730aa1c263925f75db631a"
}
private fun isLocationEnabled():Boolean{
val locationManager:LocationManager=activity?.getSystemService(Context.LOCATION_SERVICE) as LocationManager
return locationManager.isProviderEnabled(LocationManager.GPS_PROVIDER) || locationManager.isProviderEnabled(
LocationManager.NETWORK_PROVIDER
)
}
private fun requestPermission(){
ActivityCompat.requestPermissions(
requireActivity(), arrayOf(android.Manifest.permission.ACCESS_COARSE_LOCATION,
android.Manifest.permission.ACCESS_FINE_LOCATION),
PERMISSION_REQUEST_ACCESS_LOCATION
)
}
private fun checkPermission():Boolean{
if(ActivityCompat.checkSelfPermission(requireActivity(),
android.Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(requireActivity(),
android.Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED)
{
return true
}
return false
}
@Suppress("DEPRECATION")
override fun onRequestPermissionsResult(
requestCode: Int,
permissions: Array<out String>,
grantResults: IntArray
) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults)
if(requestCode== PERMISSION_REQUEST_ACCESS_LOCATION)
{
if(grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED)
{
Toast.makeText(activity?.applicationContext, "Granted", Toast.LENGTH_SHORT).show()
getCurrentLocation()
}
else{
Toast.makeText(activity?.applicationContext, "Denied", Toast.LENGTH_SHORT).show()
}
}
}
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?): View? {
fragmentHomeBinding = DataBindingUtil.inflate(inflater, R.layout.fragment_home, container, false)
// Inflate the layout for this fragment
return fragmentHomeBinding.root
}
}
Here's the error that shows up on logcat:
2022-05-20 17:45:20.582 22026-22048/com.example.weather D/EGL_emulation: app_time_stats: avg=30.74ms min=18.05ms max=34.54ms count=33
2022-05-20 17:45:21.416 22026-22026/com.example.weather D/AndroidRuntime: Shutting down VM
2022-05-20 17:45:21.417 22026-22026/com.example.weather E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.weather, PID: 22026
kotlin.UninitializedPropertyAccessException: lateinit property fragmentHomeBinding has not been initialized
at com.example.weather.Home.onCreate(Home.kt:58)
at androidx.fragment.app.Fragment.performCreate(Fragment.java:2949)
at androidx.fragment.app.FragmentStateManager.create(FragmentStateManager.java:475)
at androidx.fragment.app.FragmentStateManager.moveToExpectedState(FragmentStateManager.java:278)
at androidx.fragment.app.FragmentManager.executeOpsTogether(FragmentManager.java:2189)
at androidx.fragment.app.FragmentManager.removeRedundantOperationsAndExecute(FragmentManager.java:2100)
at androidx.fragment.app.FragmentManager.execPendingActions(FragmentManager.java:2002)
at androidx.fragment.app.FragmentManager.dispatchStateChange(FragmentManager.java:3138)
at androidx.fragment.app.FragmentManager.dispatchActivityCreated(FragmentManager.java:3072)
at androidx.fragment.app.FragmentController.dispatchActivityCreated(FragmentController.java:251)
at androidx.fragment.app.FragmentActivity.onStart(FragmentActivity.java:502)
at androidx.appcompat.app.AppCompatActivity.onStart(AppCompatActivity.java:246)
at android.app.Instrumentation.callActivityOnStart(Instrumentation.java:1455)
at android.app.Activity.performStart(Activity.java:8076)
at android.app.ActivityThread.handleStartActivity(ActivityThread.java:3660)
at android.app.servertransaction.TransactionExecutor.performLifecycleSequence(TransactionExecutor.java:221)
at android.app.servertransaction.TransactionExecutor.cycleToPath(TransactionExecutor.java:201)
at android.app.servertransaction.TransactionExecutor.executeLifecycleState(TransactionExecutor.java:173)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:97)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2210)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loopOnce(Looper.java:201)
at android.os.Looper.loop(Looper.java:288)
at android.app.ActivityThread.main(ActivityThread.java:7839)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
2022-05-20 17:45:21.435 22026-22026/com.example.weather I/Process: Sending signal. PID: 22026 SIG: 9
Help's appreciated, thanks.
CodePudding user response：
Your Fragment viewbinding instance fragmentHomeBinding is initialised at onCreateView() life cycle method. But you are accessing at onCreate() lifecycle method. In Fragment lifecycle, onCreate() will be called before onCreatedView().
As a result you are accessing an object which is not initialised. To resolve the issue, move your viewbinding reference code in onCreate() to onCreateView() as below.
override fun onCreateView(
inflater: LayoutInflater, container: ViewGroup?,
savedInstanceState: Bundle?): View? {
fragmentHomeBinding = DataBindingUtil.inflate(inflater, R.layout.fragment_home, container, false)
fragmentHomeBinding.etGetCityName.setOnEditorActionListener { v, actionId, keyEvent ->
if(actionId == EditorInfo.IME_ACTION_SEARCH)
{
getCityWeather(fragmentHomeBinding.etGetCityName.text.toString())
val view = activity?.currentFocus
if(view!=null)
{
val imm:InputMethodManager=
activity?.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
imm.hideSoftInputFromWindow(view.windowToken, 0)
fragmentHomeBinding.etGetCityName.clearFocus()
}
true
}
else false
}
// Inflate the layout for this fragment
return fragmentHomeBinding.root
}