ios - 如何在 swift 的第二个日期选择器中显示第一个日期选择器的选定日期

Question

我在我的代码中使用了两个 datePickers，当我们点击第二个 datePicker 时，我想在第二个中显示第一个 datePicker 的选定日期>。为此，我使用了 DatePickerDialog 的 pod。我已经尝试了所有方法，但我无法将第一个选定日期设置为第二个 datePicker 的开始日期。为此，我正在使用 pod DatePickerDialog。请根据此告诉我解决方案。我正在使用这个 pods https://github.com/squimer/DatePickerDialog-iOS-Swift

请看我的代码:

if textField == self.leaveField {
        ShowDropDown()
        textField.endEditing(true)
    }else if textField == self.fromDateField {
        DatePickerDialog().show("Select Date", doneButtonTitle: "Done", cancelButtonTitle: "Cancel", datePickerMode: .date) {
                (date) -> Void in
            if let dt = date {
                //UserDefaults.standard.set(dt, forKey: "startDate")
                let formatter = DateFormatter()
                formatter.dateFormat = "yyyy-MM-dd"
                self.fromDateField.text = formatter.string(from: dt)

            }
            textField.endEditing(true)
        }

    }else if textField == self.toDateField {
        //let updatedDate = UserDefaults.standard.value(forKey: "startDate")
        DatePickerDialog().show("Select Date", doneButtonTitle: "Done", cancelButtonTitle: "Cancel", datePickerMode: .date) {
                (date) -> Void in
            if let dt = date {
                let formatter = DateFormatter()
                formatter.dateFormat = "yyyy-MM-dd"
                self.toDateField.text = formatter.string(from: dt)

                let start = self.fromDateField.text
                let end = self.toDateField.text
                let dateFormatter = DateFormatter()
                dateFormatter.dateFormat = "yyyy-MM-dd"

                let startDate:NSDate = dateFormatter.date(from: start!) as! NSDate
                let endDate:NSDate = dateFormatter.date(from: end!) as! NSDate

                let components = Date.daysBetween(start: startDate as Date, end: endDate as Date)
                //let components = cal.components(unit, fromDate: startDate, toDate: endDate, options: nil)
                //let components = cal.components(unit, fromDate: startDate, toDate: endDate, options: nil)


                self.totalDaysLbl.text = "Total Days " + "\(components)"
                let char: Character = "-"
                let string = self.totalDaysLbl.text
                let result = string?.range(of: "\(char)")
                if let result1 = result{
                    let otherAlert = UIAlertController(title: "Sorry!", message: "You cannot set the date in negative.", preferredStyle: UIAlertControllerStyle.alert)

                    let dismiss = UIAlertAction(title: "OK", style: UIAlertActionStyle.cancel, handler: nil)

                    otherAlert.addAction(dismiss)

                    self.present(otherAlert, animated: true, completion: nil)
                    self.totalDaysLbl.text = ""
                }
            }
        }
        textField.endEditing(true)
    }

Answer 1

在使用之前，您应该始终阅读 API 文档。您可以在 show 方法中传递一些参数来实现此目的。您可以先将第一个 textField 字符串转换为 date，如下所示，

let formatter = DateFormatter()
formatter.dateFormat = "yyyy-MM-dd"
let selectedDate = formatter.date(from: self.fromDateField.text!)

然后使用下面的方法将这个date作为defaultDate传递，

open func show(_ title: String,
    doneButtonTitle: String = "Done",
    cancelButtonTitle: String = "Cancel",
    defaultDate: Date = Date(),
    minimumDate: Date? = nil, 
    maximumDate: Date? = nil,
    datePickerMode: UIDatePickerMode = .dateAndTime,
    callback: @escaping DatePickerCallback) {