I use lazyVStack lazyGrid and ScrollView to build a Symbol Picker. But you know, there are more than 1300 symbols in Symbol Library. So I use LazyVStack and LazyVGrid. Here is my code: ScrollView { LazyVStack { VStack(alignment: .leading) { CategoryNameIndicator() LazyVGrid(columns: columns) { ForEach(symbolGroup.symbolsName, id: \.self) { symbol in SymbolPickerCell(symbol: symbol, canBeSelected: true, selectedSymbol: $symbolLibrary.selectedSymbol)   .padding(15) .padding(.bottom, 5) } } .compositingGroup() // -> I don't know if this will improve the performance. But I used. } } } My problem is: When I scroll very fast. CPU usage will goes to 100% and the performance is reeeally bad. Scrolling Animation is caton. Do you have any suggestions?

Could you please provide a option for developers to convert drawing shape to ideal shape? Something like this: canvas.convertIdealShape = true (default by false)

In the session, I have seen a lot of examples of rainbow effects and I'd like to bring it into my app written by SwiftUI, but one thing missing is that I'm not sure how to implement customizable markdown analysis and how to set the style for it. Please help me, maybe give me some ideas? or just some suggestions.

In the past, I use UIApplication.shared.windows.first?.safeAreaInsets.bottom to get the bottom safe area, but in iOS 15, there is an warning shows that windows has been deprecated. My project is written in SwiftUI, so is there a way to get the global safeAreaInsets again and fits iOS 15?

I am working on a SwiftUI project and in a subview I use @FetchRequest to fetch data from CoreData. I have a menu to let user select which data to fetch, and by default I want to fetch all datas. The problem is when user open the menu and select a category then it refetch the data, it's correct and when user close the menu, the nsPredicate that the user have given will disappear and switch to the default predicate. I tried to write the same pattern code on 'EarthQuake' sample app, it has the same problem. And here is the code: List(selection: $selection) {                 ListView(search: $searchText)             }             .background(toggle ? Color.red.opacity(0.01) : nil)             .toolbar {                 ToolbarItem(placement: .bottomBar) {                     Button {                         toggle.toggle()                     } label: {                         Text("Toggle")                     }                 }             }             .searchable(text: $searchText) ListView: struct ListView: View {     @FetchRequest(sortDescriptors: [SortDescriptor(\.time, order: .reverse)]) // predicate: nil     private var quakes: FetchedResults<Quake>     @Binding var search: String     var body: some View {         ForEach(quakes, id: \.code) { quake in             NavigationLink(destination: QuakeDetail(quake: quake)) {                 QuakeRow(quake: quake)             }         }         .onChange(of: search) { newValue in             quakes.nsPredicate = newValue.isEmpty ? nil : NSPredicate(format: "place CONTAINS %@", newValue)         }     } } I can filter data by typing in the search field but when I click on Toggle Button, it may refresh the ParentView which cause the @fetchRequest to update and nsPredicate return to nil. Is this a bug? Or maybe my understand was wrong. And is there any good suggestions?

I have done the same thing in SwiftUI using UIViewRepresentable, but toolPicker doesn't show so I checked isFirstResponder property and I found that it was still false after I called canvas.becomeFirstResponder(). Check this out: struct NoteCanvasView: UIViewRepresentable {     func makeUIView(context: Context) -> PKCanvasView {         let canvas = PKCanvasView()         canvas.drawingPolicy = .anyInput         canvas.delegate = context.coordinator.self                  let toolPicker = PKToolPicker()         toolPicker.setVisible(true, forFirstResponder: canvas)         toolPicker.addObserver(canvas)         print(canvas.canBecomeFirstResponder)         canvas.becomeFirstResponder()         print(canvas.isFirstResponder)         return canvas     }          func updateUIView(_ canvas: PKCanvasView, context: Context) {         canvas.becomeFirstResponder()     }          func makeCoordinator() -> Coordinator {         Coordinator(self)     }          class Coordinator: NSObject {         var parent: NoteCanvasView         init(_ parent: NoteCanvasView) {             self.parent = parent         }     } } I found canvas.canBecomeFirstResponder returns true and canvas.isFirstResponder always returns false. Is this a bug in current version of SwiftUI??

I am working on an app that allow user to taking notes, and I want to support inline editing that means users can use PencilKit feature and edit text in a single note just like the Notes app. Is there any good idea to achieve this using SwiftUI?

How to add a custom button to the Edit Menu on both iOS and iPadOS natively using SwiftUI. I have seen many ways to implement custom button using UIKit but wondering how to use SwiftUI to achieve the same thing. I have never seen any modifiers or Menus about this. I guest there is no way to do that. Any idea about this? or is it a future update for SwiftUI ??

I have tried a lot of codes to see what’s the difference between browser and editor, but I can’t find some changes between those two things, so i’m wondering what’s the difference between browser and editor?

Error Code: error build: Command CompileSwift failed with a nonzero exit code My Code: .backgroundTask(.appRefresh("checkValidity")) { //   scheduleAppRefresh() //  checkRecords() }

Is there any convenient way to back deploy the NavigationStack or NavigationSplitView?? The real problem is if I want to back support iOS 15 or 14, I must conditionally switch between NavigationView and NavigationStack / NavigationSplitView. Here is how I did for NavigationStack, but I have no idea how to deal with NavigationSplitView import SwiftUI struct NavigationStack<Content: View>: View {     var content: () -> Content     var body: some View {         if #available(iOS 16.0, macOS 13.0, *) {             SwiftUI.NavigationStack {                 content()             }         } else {             NavigationView {                 content()             }.navigationViewStyle(.stack)         }     } } Will the new NavigationStack and NavigationSplitView back support old devices? I think these behaviors in previous OS is not new features.

In iOS 16, the primary action of the Menu cannot be triggered. The Menu itself will always pops up instead of performing the primary action. I have tried to use iOS 15 simulator to preview the same code. It works well.

App shortcuts can only be added to Shortcut Action List, but not a separate App Shortcuts appears at the bottom of the Shortcuts app. Now it only has the default Voice Memo App. It successfully appeared in beta 2/3, but I'm not sure if it appeared in (beta 3 update). But in beta 4, it disappeared. I have no idea how to make it visible again!!!

How to add hosting base URL to a package(not a project)? is it possible to add an existing Swift package to my project as a target?

Here is the implementation. import SwiftUI import PencilKit struct DrawingCanvas_bug: UIViewRepresentable { typealias UIViewType = PKCanvasView private let toolPicker = PKToolPicker() @Binding var drawing: PKDrawing var isOpaque: Bool = true var drawingDidChange: ((PKDrawing) -> Void)? func makeUIView(context: Context) -> PKCanvasView { let canvasView = PKCanvasView(frame: .zero) canvasView.drawing = drawing canvasView.delegate = context.coordinator canvasView.backgroundColor = .clear canvasView.isOpaque = isOpaque canvasView.alwaysBounceVertical = true // The size of the canvas is Zero, so I cannot update the ZoomScale now. // context.coordinator.updateZoomScale(for: canvasView) toolPicker.setVisible(true, forFirstResponder: canvasView) toolPicker.addObserver(canvasView) canvasView.becomeFirstResponder() return canvasView } func updateUIView(_ canvasView: PKCanvasView, context: Context) { DispatchQueue.main.async { // We can get the correct ZoomScale and the correct ContentSize, but part of the drawing is not visible. // Using the select tool can select them. context.coordinator.updateZoomScale(for: canvasView) } } func makeCoordinator() -> Coordinator { Coordinator(self) } static func dismantleUIView(_ canvasView: PKCanvasView, coordinator: Coordinator) { canvasView.resignFirstResponder() } } extension DrawingCanvas_bug { class Coordinator: NSObject, PKCanvasViewDelegate { var host: DrawingCanvas_bug init(_ host: DrawingCanvas_bug) { self.host = host } func canvasViewDrawingDidChange(_ canvasView: PKCanvasView) { host.drawing = canvasView.drawing if let action = host.drawingDidChange { action(canvasView.drawing) } updateContentSizeForDrawing(for: canvasView) } func updateZoomScale(for canvasView: PKCanvasView) { let canvasScale = canvasView.bounds.width / 768 canvasView.minimumZoomScale = canvasScale canvasView.maximumZoomScale = canvasScale canvasView.zoomScale = canvasScale updateContentSizeForDrawing(for: canvasView) } func updateContentSizeForDrawing(for canvasView: PKCanvasView) { let drawing = canvasView.drawing let contentHeight: CGFloat if !drawing.bounds.isNull { contentHeight = max(canvasView.bounds.height, (drawing.bounds.maxY + 500) * canvasView.zoomScale) } else { contentHeight = canvasView.bounds.height } canvasView.contentSize = CGSize(width: 768 * canvasView.zoomScale, height: contentHeight) } } } And here is how I use: NavigationSplitView(columnVisibility: .constant(.doubleColumn)) {     List(selection: $selection) {         ForEach(drawingModel.drawings, id: \.uuidString) {             DrawingRow(drawingData: $0)         }     } } detail: {     DrawingView() } .navigationSplitViewStyle(.balanced) // <- If I use automatic style, PKCanvasView's size is correct