I've problems with NSDate. It's simple to write the current date in "println". How I could put my current date as a Label? This is my code:
var timer = NSTimer()
override func viewDidLoad() {
super.viewDidLoad()
timer = NSTimer.scheduledTimerWithTimeInterval(1,target:self, selector: Selector("update"),userInfo: nil, repeats :true)
let date = NSDate()
println(NSDate)
}
let formatter = NSDateFormatter
formatter.dateFormat = "yyyy-MM-dd" // Set the way the date should be displayed
someLabel.text = formatter.stringFromDate(someDate)
See Date Formatting Guide
for more info on "yyyy-MM-dd" possibilities
Related
I am new in this forum but it helped me a lot in coding.
Currently I am trying to code an iOS App as a time calculator in Swift (Xcode 11.2.1)
It should be able to pick a time from the DatePicker component and add 8 hours worktime to it.
So the function is to display the time you can leave your workplace without getting negative in your flextime.
It should be displayed in the Label component.
import UIKit
class ViewController: UIViewController {
#IBOutlet weak var dateLabel: UILabel!
#IBOutlet weak var datePicker: UIDatePicker!
#IBAction func datePickerChanged(_ sender: Any) {
let dateFormatter = DateFormatter()
dateFormatter.timeStyle = DateFormatter.Style.short //show time in h:mm format
dateFormatter.locale = Locale(identifier: "de-DE") //locale Germany
let endTime = dateFormatter.date // declaring as date
let calendar = Calendar.date(from: endTime) // get time from UIDatePicker
let addHours = Calendar.date(byAdding: .hour, value: 8, to: endTime) // add 8 hours
let endTimeString = dateFormatter.string(from: endTime) //convert time from date to String
dateLabel.text = endTimeString // show calculated time in UILabel
}
}
I am getting 3 errors.
In the first let calendar line it says:
Instance member 'date' cannot be used on type 'Calendar'; did you mean to use a value of this type instead?
In the following let addHours line I am getting the same error again, what is the point here?
The last error starts at the line when I am trying to convert the time from type date to String.
Cannot convert value of type '(String) -> Date?' to expected argument type 'Date'
Anyone could help me?
I think you want something like this:
#IBAction func datePickerChanged(_ sender: UIDatePicker) {
var pickerDate = sender.date
let calendar = Calendar.current
guard let endDate = calendar.date(byAdding: .hour, value: 8, to: pickerDate) else { return }
let dateFormatter = DateFormatter()
dateFormatter.timeStyle = DateFormatter.Style.short //show time in h:mm format
dateFormatter.locale = Locale(identifier: "de-DE") //locale Germany
var endTimeString = dateFormatter.string(from: endDate) //convert time from date to String
dateLabel.text = endTimeString // show calculated time in UILabel
}
First, you need to get the selected date from the UIDatePicker.
Then, for date calulations, you need to specify a calendar to work with. Typically the current calendar is what you want (this is the calendar specified for the device). Then, add 8 hours and convert it to a string.
Btw.: you need to keep in mind that when the user picks a date in the evening, there is a "day flip" when you add 8 hours.
Update
To add somthing like 8 hours and 13 minutes, it's best to use DateComponents:
var now = Date()
var calendar = Calendar.current
var addComp = DateComponents(calendar:calendar,
hour:8,
minute:13)
if let then = calendar.date(byAdding: addComp, to: now, wrappingComponents:false) {
print(now)
print(then!)
}
I'm setting a date on my text field like so...
override func viewDidLoad() {
super.viewDidLoad()
showDatePicker()
}
func showDatePicker() {
datePickerStartDate.datePickerMode = .date
datePickerStartDate.addTarget(self, action: #selector(EventDetailViewController.startDatePickerSelect(sender:)), for: .valueChanged)
startDateTextfield.inputView = datePickerStartDate
}
#objc func startDatePickerSelect(sender: UIDatePicker) {
let formatter = DateFormatter()
formatter.dateStyle = .medium
startDateTextfield.text = formatter.string(from: sender.date)
}
This opens a datepicker on tap on the textfield and sets the date. But what I want is after I select the date, I want the time picker also to show up so that I can set the time also. And this time should get appended to the date that was set initially. How can I achieve that..?
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "hh:mm"
You can get the time of your choice from the string as :
let timeStr = "2:00"
var time = dateFormatter.dateFromString(timeStr)
Or you can add and subtract specific time from the current date as :
//It will give you the time by adding 5 minutes to the current time you can use (-5*60) to get the time 5 minute back.
var date = Date().addingTimeInterval(TimeInterval(5*60))
var timeStr = dateFormatter.string(from: date)
My code below creates a date picker and has it select a date and time. All I want to do is when the date picker's date and time match the user's phone's date and time is to print the line "cool". That's it. I commented the line that is causing me problems.
import UIKit
var dateFormatter : DateFormatter!
let datePicker2 = UIDatePicker();
let date = Date()
class ViewController: UIViewController {
#IBOutlet var dateLabel: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
let datePicker : UIDatePicker = UIDatePicker(frame: CGRect(x: 0,y: 330,width: self.view.frame.size.width,height: 220))
datePicker.datePickerMode = UIDatePickerMode.dateAndTime
self.view.addSubview(datePicker)
datePicker.addTarget(self, action: #selector(ViewController.change(_:)), for: UIControlEvents.valueChanged)
dateFormatter = DateFormatter()
dateFormatter.dateFormat = "YYYY-MM-dd hh:mm"
}
#IBAction func change(_ sender : UIDatePicker)
{
dateLabel.text = dateFormatter.string(from: sender.date)
///print cool line; what I have does not work
if dateLabel.text == String(describing: date){
print("cool")
}
}
}
Your primary issue is how you compare the two dates. You should be using the same date formatter to convert both Date instances to strings in the same format. Then you can compare the two strings.
#IBAction func change(_ sender : UIDatePicker)
{
let pickerString = dateFormatter.string(from: sender.date)
let nowString = dateFormatter.string(from: Date())
dateLabel.text = pickerString
if pickerString == nowString {
print("cool")
}
}
You are also using the wrong format. You need "yyyy-MM-dd HH:mm". YYYY is slightly different. You always want yyyy unless you have a clearly understood and specific need to use YYYY. And for the hour you want HH instead of hh. HH is a 24-hour hour while hh is a 12-hour hour. Only use hh is you also use a (for AM/PM).
And your properties should be inside the class, not outside.
Move datePicker2 inside the class.
date is now obsolete based on my answer so you can remove it completely.
dateFormatter should also be moved inside the class.
What I am trying to accomplish:
I am trying to make an enter button that checks the date in the UITextField to see if it is before the current date(any date that is today) and if the date in the UITextField is in the past, I want to throw an error/alert to tell the user to enter a date in the future--possibly a week or month from the current date.
A little background:
I made a viewController with a textfield that a user is going to enter a
date into and the way this works is the user presses on the textField and
a datePicker pops up allowing them to update the textField with the datePicker.
The problem I am running into:
This all works fine until I want to compare the date in the textField with the current date. This is because the date in the textField is a string and not a date that NSDate can recognize.
My question basically is
How do I convert the string date in the TextField into a format that NSDate can recognize?
Here is my code for my enterButton function:
#IBAction func enterButton(sender: AnyObject) {
let dateFormatter = NSDateFormatter()
var raceDate = raceDateTextField.text
let currentDate = NSDate()
raceDate = dateFormatter.stringFromDate(sender.date)
if currentDate.compare(raceDate) == NSComparisonResult.OrderedDescending {
print("Race Date is earlier than Current Date")
}
}
I'm getting the error
cannot convert value of type 'String?' to expected argument type 'NSDate' # the line below
if currentDate.compare(raceDate) == NSComparisonResult.OrderedDescending {
print("Race Date is earlier than Current Date")
}
Here is the my code for updating my textField using a datePicker just for reference:
#IBAction func textFieldEditing(sender: UITextField) {
let datePicker:UIDatePicker = UIDatePicker()
datePicker.datePickerMode = UIDatePickerMode.Date
sender.inputView = datePicker
datePicker.addTarget(self, action: #selector(SecondViewController.datePickerValueChanged), forControlEvents: UIControlEvents.ValueChanged)
}
func datePickerValueChanged(sender:UIDatePicker) {
let dateFormatter = NSDateFormatter()
dateFormatter.dateStyle = NSDateFormatterStyle.MediumStyle
dateFormatter.timeStyle = NSDateFormatterStyle.NoStyle
raceDateTextField.text = dateFormatter.stringFromDate(sender.date)
}
Am I going about this wrong logically?
Any help with this will be greatly appreciated! :)
EDIT/UPDATE!
I made the changes like you guys advised and I am getting the same error at the same line.
Here is my updated code:
#IBAction func enterButton(sender: AnyObject) {
let dateFormatter = NSDateFormatter()
var raceDate = raceDateTextField.text
dateFormatter.dateFormat = "dd/MM/yyyy"
var minimumDate: NSDate? = NSDate()
raceDate = dateFormatter.stringFromDate(sender.date)
if minimumDate!.compare(raceDate) == NSComparisonResult.OrderedDescending {
print("Race Date is earlier than Current Date")
}
}
I think the (sender.date) parameter is wrong # line:
raceDate = dateFormatter.stringFromDate(sender.date)
Right now I'm thinking I entered in the wrong parameter(sender.date) because raceDate still shows up as a string data type in the if statement.
Swift 3:
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "MMM, dd, yyyy"
let raceDate = raceDateTextField.text
let date = dateFormatter.date(from: raceDate!)
let minimumDate = NSDate()
if minimumDate.compare(date!) == ComparisonResult.orderedDescending {
}
The text that is currently in your textField is a String. You need to run that through a dateFormatter and get the date (NSDate). Afterwards you can compare it to the current date.
It's basically the same thing as when you set the text in your textField, but the other way around.
see: https://developer.apple.com/reference/foundation/nsiso8601dateformatter/1643127-datefromstring
You said that you want to compare the date in the textField with the current date.
So just create and set a minimum date for the date picker to today. var minimumDate: NSDate?
For example:
if minimumDate.compare(raceDate) == NSComparisonResult.OrderedDescending {
print("Race Date is earlier than Current Date. Are you a time traveler?")
}
#IBAction func enterButton(sender: AnyObject) {
let myDate = raceDateTextField.text
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ss.SSSZ"
let date = dateFormatter.dateFromString(myDate)!
dateFormatter.dateFormat = "dd/MM/yyyy"
let dateString = dateFormatter.stringFromDate(date)
}
Got it working correctly, thanks to #Amit Jagesha, #tymac, #Andrei Filip, and #Leo Dabus
Here is the end product in case anybody else has a similar problem and for future reference.
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "MMM, dd, yyyy"
let raceDate = raceDateTextField.text
let date = dateFormatter.dateFromString(raceDate!)
let minimumDate = NSDate()
if minimumDate.compare(date!) == NSComparisonResult.OrderedDescending {
}
First I display a UIDatePicker on the screen and allow the user to choose a date and time. I save that value like this, which gets a date format that looks like this: 6/1/16, 1:47 PM
let time = NSDateFormatter.localizedStringFromDate(datePicker.date, dateStyle: .ShortStyle, timeStyle: .ShortStyle)
Later on in the application, I want users to be able to edit their original date, so when a button is pressed, I would like the UIDatePicker to display the time that they had originally chosen.
I am using the following code to try to make that happen, although the app keeps getting a runtime error because the date is always nil.
let dateFromatter = NSDateFormatter()
let date = dateFromatter.dateFromString("6/1/16, 1:47 PM")
datePicker.setDate(date!, animated: true)
Thank you for your help!
You are having an issue with the date format and not with the date picker.
#IBOutlet weak var datePicker: UIDatePicker!
override func viewDidLoad() {
super.viewDidLoad()
let dateFromatter = NSDateFormatter()
dateFromatter.dateFormat = "M/d/yy, H:mm"
if let date = dateFromatter.dateFromString("6/1/16, 1:47") {
datePicker.setDate(date, animated: true)
}
}
For a short style string use below format:
let dateFormatter = NSDateFormatter()
dateFormatter.dateFormat = "M/d/yy, H:mm"
dateFormatter.stringFromDate(NSDate())