swift5.1

In Swift, how does one assign Data to array of UInt32?

由 北城余情 提交于 2020-03-04 16:30:27
问题 I have Swift code which reads a binary file representing a sequence of UInt32 values like this: let fileData = binaryFile.readData(ofLength: 44) guard fileData.count > 0 else { break } let headerData = fileData.withUnsafeBytes { Array(UnsafeBufferPointer<UInt32>(start: $0, count: 11)) } let polyCount = headerData[1].bigEndian let polyFlags = headerData[2].bigEndian I'd not used the program containing this code for a while, but when returning to it recently, it still works as expected, but now

How can I use Navigation in alert using SwiftUI

由 亡梦爱人 提交于 2020-02-12 01:33:08
问题 I'm working on a Bluetooth Application.It has onboarding and dashboard.On the Onboarding there is pairing and instructions on how to use the module, and the dashboard controls the peripheral device.So I need to unpair using an alert and navigate it to a different page called Onboarding .How can I navigate to a different view using an alert. Code Block import SwiftUI import BLE struct Dashboard: View { @EnvironmentObject var BLE: BLE @State private var showUnpairAlert: Bool = false @State

Error: Missing return in a closure expected to return 'UIViewController' (Xcode, Swift, iOS 13)

由 本秂侑毒 提交于 2020-01-14 07:01:11
问题 I'm getting the error: "Missing return in a closure expected to return 'UIViewController'" on the bolded line. How can I fix this? Thank you!! Var window: UIWindow? func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool { FirebaseApp.configure() let hasSession = UserDefaults.standard.value(forKey: "UserHasSubmittedPassword") as? Bool let vc: UIViewController = { if let hasSession = hasSession, hasSession ==

Swift: Receiving UDP packets from server on serial port monitor but not in ios app

由 一曲冷凌霜 提交于 2020-01-03 06:19:06
问题 I send UDP packets to a wifi module and receive them and i monitor them in serial port monitor successfully but unable to receive them in iOS app. I'm using Network Framework both for connecting and receive. The connection part works perfectly but when i set a listener to the port, and try to get rsponse the receiveMessage doesn't get called although i see outpackets that module sends. class func connect() { connection = NWConnection(host: hostUDP, port: portUDP, using: .udp) connection?

Difference between @propertyDelegate and @propertyWrapper

由 大憨熊 提交于 2019-12-23 15:25:57
问题 Which is the difference between @propertyWrapper and @propertyDelegate ? In all WWDC19 videos they talk about @propertyWrapper , however all actual implementation use @propertyDelegate (i.e SwiftUI - State); the compiler on Xcode 11 Beta seems to accept both and ask for the exact same requirement: @propertyDelegate struct A { } // Property delegate type 'A' does not contain a non-static property named 'value' @propertyWrapper struct A { } // Property delegate type 'A' does not contain a non

Function Builder not working when only one value?

由 ﹥＞﹥吖頭↗ 提交于 2019-12-22 11:35:43
问题 I have a functionBuilder @_functionBuilder struct MyBuilder { static func buildBlock(_ numbers: Int...) -> Int { var result = 0 for number in numbers { result += number * 2 } return result } } Function func myFunc(@MyBuilder builder: () -> Int) -> Int { builder() } use let a = myFunc { 10 20 } print(a) // print 60 is work! but let b = myFunc { 10 } print(b) // print 10? Why is b not 20? I try add other buildBlock static func buildBlock(number: Int) -> Int { return number * 2 } But not working

Module compiled with Swift 5.1 cannot be imported by the Swift 5.1.2 compiler

由 我们两清 提交于 2019-12-17 18:11:18
问题 I have a framework (in this instance it's RxSwift) which I've compiled using Xcode 11.0 into the traditional RxSwift.framework style package This imported fine into Xcode 11.0 and also 11.1 never had any problems with it Today, upon Apple's release of Xcode 11.2, I upgraded, and I am presented with the error: Module compiled with Swift 5.1 cannot be imported by the Swift 5.1.2 compiler I'm used to swift compiler mismatches, and I'm aware I can just recompile RxSwift using Xcode 11.2 and carry

Ambiguous reference to member 'buildBlock()'

由 ↘锁芯ラ 提交于 2019-12-10 14:48:41
问题 I've been trying to make an app for iOS 13 using Swift UI but I keep getting this weird error: "ambiguous reference to member 'buildBlock()'". No matter what I do the error won't go away. I tried commenting of sections of code at a time to see which part might have been causing the issue, but the only thing that ever worked was commenting out the entire view. I've tried cleaning my build folder and deleting derived data. I also tried restarting my computer and Xcode multiple times, nothing

Function Builder not working when only one value?

由 二次信任 提交于 2019-12-05 22:19:38
I have a functionBuilder @_functionBuilder struct MyBuilder { static func buildBlock(_ numbers: Int...) -> Int { var result = 0 for number in numbers { result += number * 2 } return result } } Function func myFunc(@MyBuilder builder: () -> Int) -> Int { builder() } use let a = myFunc { 10 20 } print(a) // print 60 is work! but let b = myFunc { 10 } print(b) // print 10? Why is b not 20? I try add other buildBlock static func buildBlock(number: Int) -> Int { return number * 2 } But not working :( Any idea? Any idea? What is happening in the failing case is that { 10 } is being treated as a

SwiftUI Login Page Layout

由 心不动则不痛 提交于 2019-11-30 19:43:26
问题 I am exploring SwiftUI as I am trying to build a login view and now I am facing a problem This is what I am trying to achieve: As you can see I already reached this point but I don't like my implementation struct ContentView : View { @State var username: String = "" var body: some View { VStack(alignment: .leading) { Text("Login") .font(.title) .multilineTextAlignment(.center) .lineLimit(nil) Text("Please") .font(.subheadline) HStack { VStack (alignment: .leading, spacing: 20) { Text(
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