Swift 3 以编程方式设置日期选择器的日期范围

Question

我想以编程方式创建一个日期选择器，范围从今天到 6 天后，例如今天，7/14，...7/20。

代码如下。

self.datePickerView = UIDatePicker(frame: CGRect(x: 0, y: 50, width: UIScreen.main.bounds.width, height: 180))

if let datePickerView = self.datePickerView {
    let currentDate: Date = Date()

     datePickerView.calendar = NSCalendar.current
     datePickerView.timeZone = NSCalendar.current.timeZone

     var beginComponents = DateComponents()
     beginComponents.day = 0
     datePickerView.minimumDate = Calendar.current.date(byAdding: beginComponents, to: currentDate)

     var endComponents = DateComponents()
     endComponents.day = 6
     datePickerView.maximumDate = Calendar.current.date(byAdding: endComponents, to: currentDate)

     dateSelectorView.addSubview(datePickerView)
}

日期选择器不仅显示 7 天，还显示过去日期(例如 7/12)和 future 日期(例如 7/21)。有没有办法只显示7天？

提前非常感谢!

Answer 1

似乎不可能更改 UIDatePicker 我建议实现自定义 UIPickerView 来完成您想要的操作。

在 Date 上创建扩展，并添加新方法 next(numberOfDays:from:) 和辅助方法 nextSevenDays()

extension Date { 

 static func nextSevenDays() -> [Date]{
   return Date.next(numberOfDays: 7, from: Date())
 }

 static func next(numberOfDays: Int, from startDate: Date) -> [Date]{
    var dates = [Date]()
    for i in 0..<numberOfDays {
        if let date = Calendar.current.date(byAdding: .day, value: i, to: startDate) {
        dates.append(date)
        }
    }
    return dates
    } 
}

在viewController内部设置一个数组来保存可能的日期并充当数据源

 class ViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource { 

  @IBOutlet weak var datePicker: UIPickerView!

  let availableDates: [Date] = {
    return Date.nextSevenDays()
   }

  // You'll need a DateFormatter to 'pretty print' the dates to the pickerView labels.
  lazy var dateFormatter: DateFormatter = {
      let df = DateFormatter()
      df.dateFormat = "EEEE, MMMM, dd, YYYY"
      return df
   }()

override func viewDidLoad() { 
 super.viewDidLoad() 
 self.datePicker.dataSource = self
 self.datePicker.delegate = self
}

 //Required Methods for UIPickerViewDataSource & UIPickerViewDelegate 

func numberOfComponents(in pickerView: UIPickerView) -> Int {
        return 1
    }

    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        return self.avaliableDates.count
       }

func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
    let label = dateFormatter.string(from: avaliableDates[row])
    return label
}

//Use this method to do work when a date is selected. 
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {

    print(avaliableDates[row])
}