比较时间以从数据中获取活动时间

Question

Simulator Screenshot

在上面的示例中，我有一个数据模型，其中包含将要显示的行程的不同时间。我想用实心圆圈突出显示当前时间：

struct SampleModel: Identifiable {
let id = UUID()
let title: String
let description: String
let time: Date
let icon: String

}

让timeInterval = 1652619600

class Sample: ObservableObject {
    @Published var sample2 = [SampleModel(title: "Coffee", description: "Get coffee", time: Date(timeIntervalSince1970: TimeInterval(timeInterval)), icon: "house"),
                              SampleModel(title: "Coffee", description: "Get coffee", time: Date(timeIntervalSince1970: TimeInterval(timeInterval)).adding(minutes: 30), icon: "house"),
                              SampleModel(title: "Dinner", description: "Outback Steakhouse", time: Date(timeIntervalSince1970: TimeInterval(timeInterval)).adding(minutes: 60), icon: "person"),
                              SampleModel(title: "Check Weather", description: "Use app to check weather", time: Date(timeIntervalSince1970: TimeInterval(timeInterval)).adding(minutes: 120), icon: "cloud.sun.fill"),
                              SampleModel(title: "Go To Work", description: "Leave for work", time: Date(timeIntervalSince1970: TimeInterval(timeInterval)).adding(minutes: 180), icon: "car.fill"),
                              SampleModel(title: "YouTube", description: "Watch youtube video", time: Date(timeIntervalSince1970: TimeInterval(timeInterval)).adding(minutes: 240), icon: "video.fill"),
                              SampleModel(title: "Cut Grass", description: "Work in yard", time: Date(timeIntervalSince1970: TimeInterval(timeInterval)).adding(minutes: 300), icon: "speedometer"),
                              SampleModel(title: "Ride Bike", description: "Go to the trace", time: Date(timeIntervalSince1970: TimeInterval(timeInterval)).adding(minutes: 360), icon: "bicycle"),
                              SampleModel(title: "Take Pictures", description: "Photograph the moon", time: Date(timeIntervalSince1970: TimeInterval(timeInterval)).adding(minutes: 420), icon: "camera.fill"),
                              SampleModel(title: "Boat Ride", description: "Go boating", time: Date(timeIntervalSince1970: TimeInterval(timeInterval)).adding(minutes: 480), icon: "ferry.fill"),
                              SampleModel(title: "Colorado trip", description: "Fly to Erie", time: Date(timeIntervalSince1970: TimeInterval(timeInterval)).adding(minutes: 540), icon: "airplane")]
    
    func isCurrent(date1: Date) -> Bool {
        var currentItem: Bool = false
        
        for cTime in sample2 {
            if date1 <= cTime.time  && date1 <= Date()  {
            } else {
                currentItem = false
            }
        }
        return currentItem
    }
}

上面的数据只是一个示例模拟数据，因此我可以获得 UI 并且功能正常运行。在我的内容视图中，我有。 foreach 在示例数据上循环，我想用实心圆突出显示当前项目。在 isCurrent() 函数中，我可以获得之前已经发生的所有项目，但我想要 return 最近的

ForEach(sampleVM.sample2, id: \.id) { index in
        Divider()
        ItemRowView(isCurrent: sampleVM.isCurrent(date1: index.time), isLastRow: lastRow(item: index.id), time: Date(), sample: index)
}

ItemRowView() 是我用来显示数据的。

Answer 1

由于数组已排序，您只需找到日期大于当前日期

的第一个item/index

如果找不到索引（当前日期晚于最后一项的日期）则该项目是最后一项
如果索引为 0（当前日期早于第一项的日期）则该项为 nil
否则该项目是索引 - 1 处的项目

let currentItem : SampleModel?
if let nextIndex = sample2.firstIndex(where: {[=10=].time > Date()}) {
    currentItem = nextIndex > 0 ? sample2[nextIndex - 1] : nil
} else {
    currentItem = sample2.last!
}

或者如果结果是索引

let currentIndex: Int?
if let nextIndex = sample2.firstIndex(where: {[=11=].time > Date()}) {
    currentIndex = nextIndex > 0 ? nextIndex - 1 : nil
} else {
    currentIndex = sample2.endIndex - 1
}

比较时间以从数据中获取活动时间

Compare Times to get active time from data

time

swiftui