swiftui

问题 So I have a circular progress bar that is declared like this struct ProgressBar: View { var progress: CGFloat var body: some View { let gradient = LinearGradient(...) ZStack { Circle() .stroke(lineWidth: 25) .opacity(0.3) .foregroundColor(Color.secondary) Circle() .trim(from: 0.0, to: CGFloat(min(self.progress, 1.0))) .stroke(gradient ,style: StrokeStyle(lineWidth: 25.0, lineCap: .round, lineJoin: .round)) .rotationEffect(Angle(degrees: 270.0)) .animation(.linear) } } } The variable progress

问题 I have a list of items, I want to make it possible to navigate to the details view. However, the first element in the list is always passed to this view, what could be the problem? struct ContentView: View { var array: [Object] = [Object(id: .init(),property: 1),Object(id: .init(),property: 2),Object(id: .init(),property: 3)] @State var showAlert = false @State var showDetailsView = false var body: some View { NavigationView{ List{ ForEach(array){ item in VStack{ Text(String(item.property)) }

问题 I have a list of items, I want to make it possible to navigate to the details view. However, the first element in the list is always passed to this view, what could be the problem? struct ContentView: View { var array: [Object] = [Object(id: .init(),property: 1),Object(id: .init(),property: 2),Object(id: .init(),property: 3)] @State var showAlert = false @State var showDetailsView = false var body: some View { NavigationView{ List{ ForEach(array){ item in VStack{ Text(String(item.property)) }

问题 I have a ContentView that is the root view that navigates to a DetailView. The DetailView has a navbaritem that navigates to Help2 view. I want to click a button to dismiss the Help2 view and return to the DetailView (the view from which Help2 came from). Currently, when I press a button on the Help2 view, it dismisses the view, but it returns me to the root ContentView rather than DetailView . If I navigate to the Help2 view then manually click the back button to navigate to DetailView , it

问题 I was following the Apple tutorial for SwiftUI and under 'Interfacing with UIKit' (https://developer.apple.com/tutorials/swiftui/interfacing-with-uikit) we were made to make a UIPageController. In the tutorial, they used a State property to update the currentPage variable in PageView . I wanted to experiment a little bit and decided that I want to embed the PageView in a different view and have a currentPage property update in that parent view instead. So, naturally, I changed the @State

问题 I was following the Apple tutorial for SwiftUI and under 'Interfacing with UIKit' (https://developer.apple.com/tutorials/swiftui/interfacing-with-uikit) we were made to make a UIPageController. In the tutorial, they used a State property to update the currentPage variable in PageView . I wanted to experiment a little bit and decided that I want to embed the PageView in a different view and have a currentPage property update in that parent view instead. So, naturally, I changed the @State

问题 This is basically my code I have: var myString: String? var body: some View { NavigationView { if myString != nil { CustomView(text: myString ?? "") } } } If I try without adding the ?? "" part, it doesn't work, says Value of optional type 'String?' must be unwrapped to a value of type 'String' . If I add it in as shown above, it seems to work, but why do I need to have a default empty string value if that's never going to be the case? (Since it will only reach that code if myString is not

问题 This is basically my code I have: var myString: String? var body: some View { NavigationView { if myString != nil { CustomView(text: myString ?? "") } } } If I try without adding the ?? "" part, it doesn't work, says Value of optional type 'String?' must be unwrapped to a value of type 'String' . If I add it in as shown above, it seems to work, but why do I need to have a default empty string value if that's never going to be the case? (Since it will only reach that code if myString is not

问题 I want to change the color of the selected row. As you may see, by default it has this light gray color. I have no idea how to do that since I have found no way to access this row at all. Is there any way to do that? Demo code: struct ContentView: View { var data = Array(0...20).map { "\($0)" } @State private var selected = 0 var body: some View { VStack { Picker("", selection: $selected) { ForEach(0 ..< data.count) { Text(data[$0]) } } } } } A UIKit answer would also be welcomed since I have

问题 I want to change the color of the selected row. As you may see, by default it has this light gray color. I have no idea how to do that since I have found no way to access this row at all. Is there any way to do that? Demo code: struct ContentView: View { var data = Array(0...20).map { "\($0)" } @State private var selected = 0 var body: some View { VStack { Picker("", selection: $selected) { ForEach(0 ..< data.count) { Text(data[$0]) } } } } } A UIKit answer would also be welcomed since I have