swiftui

问题 I'm trying SwiftUI tutorial in apple developer page. now I'm following transition tutorial but my transition is not working when the view added. here my code. VStack(alignment: .leading) { HStack() { // title Text(titleText) .font(.headline) .padding() Spacer() // button Button(action: { withAnimation { self.showDetail.toggle() } }) { Image(systemName: "chevron.right.circle") .imageScale(.large) .rotationEffect(.degrees(showDetail ? 90 : 0)) .padding() } } // detail if showDetail { Text

问题 I create a set of side by side pickers in an HStack by calling the view below. The "control" area for each picker is much wider to the left of the picker than it should be. ".clipped()" is supposed to fix this, but it is not working. At some point when I was developing the code, it was working, but now I can't get it back. When I try to manipulate the pickers, I can move the rightmost one anywhere on the right 3 columns. The left column cannot be manipulated at all. What is going on here?

问题 I'm currently developing an application using SwiftUI. I want to use a UserDefaults value in this app. So I made a code below. But in this case, when I reboot the app(the 4'th process in the process below), I can't get value from UserDefaults... Build and Run this project. Pless the home button and the app goes to the background. Double-tap the home button and remove the app screen. press the app icon and reboot the app. Then I want to get value from UserDefaults. to resolve this problem how

问题 I'm currently developing an application using SwiftUI. I want to use a UserDefaults value in this app. So I made a code below. But in this case, when I reboot the app(the 4'th process in the process below), I can't get value from UserDefaults... Build and Run this project. Pless the home button and the app goes to the background. Double-tap the home button and remove the app screen. press the app icon and reboot the app. Then I want to get value from UserDefaults. to resolve this problem how

问题 I currently have this interface whereby I am putting a MapView and a UIView on top of each other. The UIView is where I put my chart overlay (eg: Heart Rate). This is fine when the device is in portrait mode. However, I would like to explore a different layout when in landscape mode whereby the UIView(HR Chart) and the MapView is side by side. Is this doable in Interface Builder? Or only in code? (I would like to only use UIKit to better support lower OSes) note : I tried in IB but can't seem

问题 I currently have this interface whereby I am putting a MapView and a UIView on top of each other. The UIView is where I put my chart overlay (eg: Heart Rate). This is fine when the device is in portrait mode. However, I would like to explore a different layout when in landscape mode whereby the UIView(HR Chart) and the MapView is side by side. Is this doable in Interface Builder? Or only in code? (I would like to only use UIKit to better support lower OSes) note : I tried in IB but can't seem

问题 I have two columns with nested data(Parent/child). Each item in first column is parent. When selecting anyone of them then it shows its child in second column as list. When selecting any item from second column then it must show "clipAttr" attribute in third column as text editor where we can edit it. Now I need help how to do that when edit the 'ClipAttr' then it automatically update in SampleDataModel collection. Below is the complete code. struct SampleClip: Identifiable, Hashable { var

问题 We know Apple has drastically simplified the SwiftUI app life cycle (WWDC20). I have seen the video of Mr.Paul Hudson about the new changes in SwiftUI in which he has explained how to access AppDelegate methods in "@main or :App" struct. I want to know if there is any way to access the SceneDelegate methods? Thanks in advance. :) 回答1: There is no access for SceneDelegate now in SwiftUI 2.0 life-cycle. Some of callbacks you can use with .onChange for [.active, .inactive, .background] states as

问题 I'm storing ~100.000 dictionary entries in a realm database and would like to display them. Additionally I want to filter them by a search field. Now I'm running in a problem: The search function is really inefficient although I've tried to debounce the search. View Model: class DictionaryViewModel : ObservableObject { let realm = DatabaseManager.sharedInstance @Published var entries: Results<DictionaryEntry>? @Published var filteredEntries: Results<DictionaryEntry>? @Published var searchText

问题 I am trying to get the maximum performance out of SwiftUI. I have a complex view and a lot of state and not sure what penalties I am paying as I calculate a lot of views programatically. The view is something like this, stripped to the bare minimum struct ComplexView : View { @State var a = 1 @State var b = 2 // .. more state // Perform function and change some of the state func doIt ( index : Int ) { // ... change some state } // Calculate some view based on state and index func calcView (