SwiftUI yana sake gudanar da body a duk lokacin da observed state ya sauya, sannan yana diff sabon view tree da tsohon kuma yana sabunta abin da ya bambanta kawai. Matsalolin performance suna zuwa daga sanya wannan diff yin aiki fiye da kima: marar tabbas, mai fanni faɗi, da computations masu tsada. Gyara shi ta hanyar sarrafa identity, ƙayyade state, da kiyaye mai sauƙi.
bodybodySwiftUI yana daidaita views tsakanin renders ta identity. Ga lists wannan shi ne id; idan id marar tabbas ne, SwiftUI yana zubar da view ɗin ya sake gina shi (yana rasa state da animations) maimakon sabunta shi.
// BAD: array index as id — reorders/inserts break identity, full rebuild
ForEach(items.indices, id: \.self) { i in Row(items[i]) }
// GOOD: stable identity tied to the data
ForEach(items) { item in Row(item) } // items: Identifiable, stable id
ObservableObject yana sake render kowace view da ke observe shi a duk lokacin da kowace @Published property ta sauya. Raba manyan models, ko koma zuwa Observation framework (@Observable, iOS 17+), wanda ke bin per-property reads don haka view ke sake render kawai lokacin da property ɗin da ta yi amfani da shi ta sauya.
@Observable final class Feed { // iOS 17: fine-grained dependency tracking
var unreadCount = 0 // a view reading only .posts won't re-render on this
var posts: [Post] = []
}
body yana gudana sau da yawa, don haka kada ka taɓa yin manyan ayyuka inline:
var body: some View {
List(sortedItems) { ... } // BAD if sortedItems sorts on every render
}
// GOOD: compute derived data in the model, not in body
LazyVStack/List don manyan collections don kada a gina off-screen rows..equatable() ko EquatableView don yanke diffing a kan stable subtrees.AnyView yana share type identity kuma yana kayar da structural diffing — guje masa a hot paths.A kan 120Hz ProMotion display kana da kimanin ~8ms a kowane frame; body da ke sort babban array ko sake render dukkan list yana zubar da frames kuma yana janks scrolling. Manyan hirar aiki suna bincika view identity da observation scope saboda a wurin ne apps na SwiftUI na gaskiya ke jinkirtawa — kuma inda ƴan gyare-gyare masu daidai ke maido da santsi.
Ɗakin karatu na tambayoyin hira na IT tare da amsoshi cikakke — daga Junior zuwa Senior.
Ba da Gudummawa