在 SwiftUI 中使用时间间隔的 DatePicker
DatePicker using Time-Interval in SwiftUI
我想在 SwiftUI 中使用 DatePicker,它工作正常并且符合预期。我想添加一个时间间隔,如解释的那样:
DatePicker("Please enter a time", selection: $wakeUp, displayedComponents: .hourAndMinute)
SwifUI 中有修改器吗?
我认为没有针对此的修饰符。但是,可以通过使用 UIViewRepresentable 包装 UIDatePicker 来 "do it yourself":
此代码的基本结构基于 Interfacing with UIKit 教程。
struct MyDatePicker: UIViewRepresentable {
@Binding var selection: Date
let minuteInterval: Int
let displayedComponents: DatePickerComponents
func makeCoordinator() -> Coordinator {
return Coordinator(self)
}
func makeUIView(context: UIViewRepresentableContext<MyDatePicker>) -> UIDatePicker {
let picker = UIDatePicker()
// listen to changes coming from the date picker, and use them to update the state variable
picker.addTarget(context.coordinator, action: #selector(Coordinator.dateChanged), for: .valueChanged)
return picker
}
func updateUIView(_ picker: UIDatePicker, context: UIViewRepresentableContext<MyDatePicker>) {
picker.minuteInterval = minuteInterval
picker.date = selection
switch displayedComponents {
case .hourAndMinute:
picker.datePickerMode = .time
case .date:
picker.datePickerMode = .date
case [.hourAndMinute, .date]:
picker.datePickerMode = .dateAndTime
default:
break
}
}
class Coordinator {
let datePicker: MyDatePicker
init(_ datePicker: MyDatePicker) {
self.datePicker = datePicker
}
@objc func dateChanged(_ sender: UIDatePicker) {
datePicker.selection = sender.date
}
}
}
struct DatePickerDemo: View {
@State var wakeUp: Date = Date()
@State var minterval: Int = 1
var body: some View {
VStack {
Stepper(value: $minterval) {
Text("Minute interval: \(minterval)")
}
MyDatePicker(selection: $wakeUp, minuteInterval: minterval, displayedComponents: .hourAndMinute)
Text("\(wakeUp)")
}
}
}
struct DatePickerDemo_Previews: PreviewProvider {
static var previews: some View {
DatePickerDemo()
}
}
不完全是 SwiftUI 解决方案,但比现有答案简单得多。将其附加到包含选择器的主体视图
.onAppear {
UIDatePicker.appearance().minuteInterval = 5
}
缺点是这将应用于视图中的所有选择器,并可能影响应用程序其他视图中的选择器,但您始终可以在这些视图中执行相同的操作(将分钟间隔设置回 1)。
我想在 SwiftUI 中使用 DatePicker,它工作正常并且符合预期。我想添加一个时间间隔,如解释的那样:
DatePicker("Please enter a time", selection: $wakeUp, displayedComponents: .hourAndMinute)
SwifUI 中有修改器吗?
我认为没有针对此的修饰符。但是,可以通过使用 UIViewRepresentable 包装 UIDatePicker 来 "do it yourself":
此代码的基本结构基于 Interfacing with UIKit 教程。
struct MyDatePicker: UIViewRepresentable {
@Binding var selection: Date
let minuteInterval: Int
let displayedComponents: DatePickerComponents
func makeCoordinator() -> Coordinator {
return Coordinator(self)
}
func makeUIView(context: UIViewRepresentableContext<MyDatePicker>) -> UIDatePicker {
let picker = UIDatePicker()
// listen to changes coming from the date picker, and use them to update the state variable
picker.addTarget(context.coordinator, action: #selector(Coordinator.dateChanged), for: .valueChanged)
return picker
}
func updateUIView(_ picker: UIDatePicker, context: UIViewRepresentableContext<MyDatePicker>) {
picker.minuteInterval = minuteInterval
picker.date = selection
switch displayedComponents {
case .hourAndMinute:
picker.datePickerMode = .time
case .date:
picker.datePickerMode = .date
case [.hourAndMinute, .date]:
picker.datePickerMode = .dateAndTime
default:
break
}
}
class Coordinator {
let datePicker: MyDatePicker
init(_ datePicker: MyDatePicker) {
self.datePicker = datePicker
}
@objc func dateChanged(_ sender: UIDatePicker) {
datePicker.selection = sender.date
}
}
}
struct DatePickerDemo: View {
@State var wakeUp: Date = Date()
@State var minterval: Int = 1
var body: some View {
VStack {
Stepper(value: $minterval) {
Text("Minute interval: \(minterval)")
}
MyDatePicker(selection: $wakeUp, minuteInterval: minterval, displayedComponents: .hourAndMinute)
Text("\(wakeUp)")
}
}
}
struct DatePickerDemo_Previews: PreviewProvider {
static var previews: some View {
DatePickerDemo()
}
}
不完全是 SwiftUI 解决方案,但比现有答案简单得多。将其附加到包含选择器的主体视图
.onAppear {
UIDatePicker.appearance().minuteInterval = 5
}
缺点是这将应用于视图中的所有选择器,并可能影响应用程序其他视图中的选择器,但您始终可以在这些视图中执行相同的操作(将分钟间隔设置回 1)。