In my application i want show message when fragment has show.
I used viewPager and BottomNavBar for show 4 fragments!
I want when click on BottomNavBar items show fragment and i want when visibility fragment show message.
I write below codes :
class HomeRegisteredFragment : Fragment() {
lateinit var toolbarTile: TextView
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
return inflater.inflate(R.layout.fragment_home_registered, container, false)
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
//Initialize
activity?.let {
toolbarTile = it.findViewById(R.id.homePage_toolbarTitle)
}
//Set title
toolbarTile.text = resources.getString(R.string.registered)
context?.let { ContextCompat.getColor(it, R.color.blue_active) }?.let {
toolbarTile.setTextColor(it)
}
}
override fun setUserVisibleHint(isVisibleToUser: Boolean) {
super.setUserVisibleHint(isVisibleToUser)
if (isVisibleToUser) {
Log.e("showFragLog", "Show")
context?.let { Toast.makeText(it, "Show", Toast.LENGTH_SHORT).show() }
}
}
}
In my above codes, when click on my BottomNavBar for show fragment, show me Log message but not show Toast message.
When click on another BottomNavBar items and again click on previous BottomNavBar item, then show Toast message.
I think in first time not initialize context in setUserVisibleHint method.
How can i initialize context for show Toast in every time?
I changed your codes with below codes :
class HomeRegisteredFragment : Fragment() {
lateinit var toolbarTile: TextView
lateinit var handler: Handler
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
return inflater.inflate(R.layout.fragment_home_registered, container, false)
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
//Initialize
activity?.let {
toolbarTile = it.findViewById(R.id.homePage_toolbarTitle)
}
}
override fun setUserVisibleHint(isVisibleToUser: Boolean) {
super.setUserVisibleHint(isVisibleToUser)
if (isVisibleToUser) {
//Initialize
handler = Handler()
//Set delay
handler.postDelayed({
Toast.makeText(requireContext(),"Show",Toast.LENGTH_SHORT).show()
}, 10)
}
}
}
First you should use requireContext() instead of context() for avoid from memory leak.
For show Toast for every time, you can initialize handler in setUserVisibleHint , then after some delay run your code!
I hope help you
Storing context in a variable is a horrible practive and most of the times leads to memory leaks, use requireContext() this method was introduced in Support Library 27.1.0. Nowdays most likely you will have a newer version or even using androidx so there is no excuse for storing a context
If you are looking for application context to show the toast message, try the below way and see if it works. Also, initialize it onCreate method so you have the activity context at that point.
val appContext = context!!.applicationContext