我试图为日历类型的应用程序制作一天选择器但由于某种原因选择一天不起作用。(我对代码中断的位置有评论 )(acalendar i-码文网

我试图为日历类型的应用程序制作一天选择器，但由于某种原因选择一天不起作用。（我对代码中断的位置有意见）。

问题是变量 selectedDate 不更新。

Basically the code has a loop from 0 to 100 days, and I just multiply current date by the iterator to get 100 future dates. I need the code to change selectedDate to whatever date I pick from the list

我有这两个变量来跟踪：

@State var currentDate = Date()
@State var selectedDate = Date()

（我认为问题来自我使用 ForEach 循环，但我不确定）

ForEach(0..<100) { day in
                                
                                if (selectedDate == (currentDate + TimeInterval((86400 * day)))) {
                                    Button {
                                        selectedDate = (currentDate + TimeInterval((86400 * day)))
                                        // error here
                                    } label: {
                                        
                                        ZStack {
                                            VStack {
                                                Text("\((currentDate + TimeInterval((86400 * day))).formatted(.dateTime.day()))")
                                                    .foregroundColor(.white)
                                                Text("\((currentDate + TimeInterval((86400 * day))).formatted(.dateTime.weekday(.short)))")
                                                    .foregroundColor(.white)
                                            }
                                        }
                                    }
                                } else {
                                    Button {
                                        selectedDate = (currentDate + TimeInterval((86400 * day)))
                                        // and here
                                    } label: {
                                        ZStack {
                                            VStack {
                                                Text("\((selectedDate + TimeInterval((86400 * day))).formatted(.dateTime.day()))")
                                                    .foregroundColor(.white)
                                                Text("\((selectedDate + TimeInterval((86400 * day))).formatted(.dateTime.weekday(.short)))")
                                                    .foregroundColor(.white)
                                            }
                                        }
                                    }
                                }
                                
                                }

你可以尝试这种方法，保持你的逻辑，但使用currentDate.addingTimeInterval(TimeInterval((86400 * day)))：

struct ContentView: View {
    @State var currentDate = Date()
    @State var selectedDate = Date()
    
    var body: some View {
        VStack {
            Text("selected day: \(selectedDate.formatted(.dateTime.day())),  \(selectedDate.formatted(.dateTime.weekday(.wide)))")
            ScrollView (.horizontal){
                HStack {
                    ForEach(0..<100) { day in
                        let theDate = currentDate.addingTimeInterval(TimeInterval((86400 * day)))
                        if (selectedDate == theDate) {
                            Button {
                                selectedDate = theDate
                            } label: {
                                VStack {
                                    Text("\(theDate.formatted(.dateTime.day()))")
                                        .foregroundColor(.green)
                                    Text("\(theDate.formatted(.dateTime.weekday(.short)))")
                                        .foregroundColor(.green)
                                }
                            }
                        } else {
                            Button {
                                selectedDate = theDate
                            } label: {
                                VStack {
                                    Text("\(theDate.formatted(.dateTime.day()))")
                                        .foregroundColor(.red)
                                    Text("\(theDate.formatted(.dateTime.weekday(.short)))")
                                        .foregroundColor(.blue)
                                }
                            }
                        }
                        
                    }
                }
            }
        }
    }
}

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