StatefulWidget State object yana da lifecycle — jeri na hanyoyin da ake kira yayin da aka create widget, update, da kuma kashe (initState, build, didUpdateWidget, dispose, da sauransu). Fahimta haka yana da mahimmanci don daidaita albarkatun da tasiri na gida da kyau.
class _MyWidgetState extends State<MyWidget> {
@override
void initState() {
super.initState();
// called ONCE when the State is created → initialize, start subscriptions,
// fetch initial data, set up controllers/listeners
}
@override
Widget build(BuildContext context) {
// called whenever the UI needs to render (often) → return the widget tree
return Container();
}
@override
void didUpdateWidget(MyWidget oldWidget) {
super.didUpdateWidget(oldWidget);
// called when the parent rebuilds with new config → react to changed inputs
}
@override
void dispose() {
// called when the State is permanently removed → CLEAN UP:
// cancel subscriptions, dispose controllers, close streams (prevent leaks!)
super.dispose();
}
}
createState → initState (once) → build (many times) → [didUpdateWidget on config change]
→ ... → dispose (once, at the end)
Other: didChangeDependencies (when InheritedWidget dependencies change)
⚠️ dispose() is CRITICAL for cleanup — failing to clean up causes MEMORY LEAKS / bugs:
→ cancel Stream subscriptions, Timers; dispose AnimationControllers, TextEditingControllers,
ScrollControllers; close StreamControllers
→ resources started in initState should be cleaned up in dispose
→ A common source of leaks: forgetting to dispose controllers/subscriptions.
Fahimta StatefulWidget lifecycle yana da mahimmanci don daidaita albarkatun da tasiri na gida da kyau a cikin Flutter, don haka ito ne ilimin aiki mai kimar.
Hanyoyin lifecycle na State object ana kira su a wurare na musamman, kuma yin amfani da su da daidai yana da mahimmanci: initState (ana kira shi sau daya kawai yayin da aka create State — wurin da za a shirya, karɓo bayanan farko, fara jama'a, da kuma saita masu sarawa/masomarsa), build (ana kira shi koda yaushe UI ta yi jiya, yana dawo da bishiyar widget), didUpdateWidget (ana kira shi yayin da mahali na iya sake ginin tare da sabuwar setup, don amsa buguwar abubuwa), da dispose (ana kira shi yayin da aka cire Jihar da gaske).
Fahimta jerin yaudara (createState → initState → build again and again → dispose) yana haifar da fahimta yaushe kowannensu ya yi.
Mafi mahimmancin abu shine fahimtar dispose yana da mahimmanci don tsarkakawa : rashin tsarkakawa albarkatun (soke jama'a Stream da Timers, toshe AnimationControllers, TextEditingControllers da ScrollControllers, rufe StreamControllers) yana haifar da iska alijihu da kurakuran — kuma maliyas saita masu sarawa da jama'a ita ce ranar arbau da ainihi na iska a cikin juna Flutter apps.
Alƙalus na saita albarkatun a initState da tsarkakawa su a dispose shine tushen rubuta mummunar widgets tare da mara iska.
Fahimtar lifecycle yana ba da daidai shirya (a initState), amsa ga canje-canjen (a didUpdateWidget), da gagarantata tsarkakawa (a dispose).
Tun da daidaita albarkatun da tasiri na gida da kyau yana da mahimmanci ga daidaitaccen Flutter apps marasa iska, kuma tun da StatefulWidget lifecycle (musamman initState don shirya da dispose don tsarkakawa) shine tsarin don haka, fahimta StatefulWidget lifecycle — babbar hanyoyin, lokacin su, da musamman mahimmancin dispose a hana iska — ita ce ilimin aiki mai mahimmanci Flutter, kila saniya domin rubuta daidaitaccen stateful widgets, mahimmancin skill don iya guje iskancin albarkatun da ke zama babbar ainihi-duniya matsala a cikin Flutter.