ios - 将 DatePicker 与 UIPickerView 同步并使用 Label 显示从中选择的值
问题描述
我需要一点帮助,因为我的作业被困住了。我需要将 PickerView 与 DatePicker 同步,并在 Label 中显示所选值。当我更改 DatePicker 上的值时,不会反映在我的 PickerView 上。谁能弄清楚为什么?这是一张图片,向您展示我目前的位置以及我的代码:
class ViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {
@IBOutlet weak var pickerView: UIPickerView!
@IBOutlet weak var datePicker: UIDatePicker!
@IBOutlet weak var labelDate: UILabel!
var days = [String]()
var months = Array<String>()
var years = [String]()
override func viewDidLoad() {
super.viewDidLoad()
let formatter = DateFormatter()
formatter.dateFormat = "dd/MMM/yyyy"
labelDate.text = formatter.string(from: datePicker.date)
// Arrays for Picker View
days = Array(1...31).map({ String($0) })
months = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"]
years = Array(2000...2030).map({ String($0) })
}
// We set number of components in the Picker View (in our case 3 columns)
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 3
}
// Get the number of elements for each component (each column)
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
switch(component) {
case 0: return months.count
case 1: return days.count
case 2: return years.count
default: return 0
}
}
// Our ViewController will adopt the protocol "UIPickerViewDelegate" and after we display data for each element on a new Row
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
switch(component) {
case 0: return months[row]
case 1: return days[row]
case 2: return years[row]
default: return nil
}
}
// Select a date from PickerView and show it in the DatePicker and also in the Label
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
let monthSelected = months[pickerView.selectedRow(inComponent: 0)]
let daySelected = days[pickerView.selectedRow(inComponent: 1)]
let yearSelected = years[pickerView.selectedRow(inComponent: 2)]
let dataString = "\(daySelected)/" + "\(monthSelected)/" + "\(yearSelected)"
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "d/MMM/yyyy"
let date = dateFormatter.date(from: dataString)
datePicker.setDate(date!, animated: true)
labelDate.text = "\(daySelected)/" + "\(monthSelected)/" + "\(yearSelected)"
// Here I need the logic for February to have 28 days always or if I know
// how to do, then to implement some Logic for Leap Years
/*
if(yearSelected % 4 == 0 && (yearSelected % 100 != 0) || (yearSelected % 400 == 0)){
february will return 29 days
} else{
february will return 28 days }
}
*/
}
// Select a date from DatePicker and show it in the UIPickerView and also in the Label
@IBAction func dateSelectedFromDatePicker(_ sender: UIDatePicker) {
let calendar = Calendar.current
let components = calendar.dateComponents([.day,.month,.year], from: self.datePicker.date)
let day = components.day
let month = components.month
let year = components.year
pickerView.selectRow(month!-1, inComponent: 0, animated: true)
pickerView.selectRow(day!-1, inComponent: 1, animated: true)
pickerView.selectRow(year!-1, inComponent: 2, animated: true)
let formatter = DateFormatter()
formatter.dateFormat = "d/MMM/yyyy"
labelDate.text = formatter.string(from: datePicker.date)
}
}
提前非常感谢您!
解决方案
组件 0 --> 月
组件 1 --> 天
组件 2 --> 年
更改此代码,确保 day!-1
, month!-1
,year!-1
代表数组天、月、年中的正确索引
这是应该更改的代码:
pickerView.selectRow(day!-1, inComponent: 1, animated: true)
pickerView.selectRow(month!-1, inComponent: 0, animated: true)
pickerView.selectRow(year!-1, inComponent: 2, animated: true)
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