I've done plenty of searching but am not finding the answer to my question.
My two UITextFields fields are resetting using the clear function. The UILabel retains the original value from the printWatts function, doesn't clear. Would appreciate any advice to resolve this small issue as I learn Swift. Thanks!
import UIKit
class ViewController: UIViewController {
#IBOutlet weak var inputFeet: UITextField!
#IBOutlet weak var inputWatts: UITextField!
#IBOutlet weak var resultsLabel: UILabel!
var stripFeet = ""
var wattValue = ""
var totalWatts : Float = 0.0
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
}
#IBAction func submitButton(sender: AnyObject) {
calculateWatts()
}
#IBAction func clearButton(sender: AnyObject) {
clear()
}
func calculateWatts() {
if let stripFeet = inputFeet.text,
wattValue = inputWatts.text,
fstripFeet = Float(stripFeet),
fwattValue = Float(wattValue){
totalWatts = fstripFeet * fwattValue
}
printWatts()
}
func printWatts() {
let formatWatts = String(format: "%0.2f", totalWatts)
resultsLabel.text = "Total watts: \(formatWatts)"
}
func clear(){
inputFeet.text = ""
inputWatts.text = ""
self.resultsLabel.text = ""
}
}
Thanks to #Eendje for suggesting that I check my connections. I had the submit and clear actions both connected to my submit button. Option drag is too convenient. All good now.
Related
I am having some trouble updating my secondViewController view in Xcode using Swift 5. I want my app to add two numbers together and show the result in the second ViewController. Although it works the first time, if I return to my previous view and change the numbers, the view does not update.
I tried using viewWillAppear, viewWillDisappear, amongst others, including NSNotificationCenter addObserve, but I have had no luck whatsoever.
Do you have any recommendations? Am I missing something?
Please see below for the code and a screenshot of my ViewControllers:
//
// ViewController.swift
//
import UIKit
var result = ""
var resultFinal = Float(result)
let finalResult = resultFinal!
class ViewController: UIViewController {
#IBOutlet weak var firstNumber: UITextField!
#IBOutlet weak var secondNumber: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
func getResult()-> Float{
guard let fNumber = firstNumber.text else {
return 0
}
let firstFloat = Float(fNumber)
guard let sNumber = secondNumber.text else {
return 0
}
let secondFloat = Float(sNumber)
let sumNumber: Float = firstFloat! + secondFloat!
return sumNumber
}
#IBAction func submitSum(_ sender: Any) {
resultFinal = getResult()
print(resultFinal!)
}
}
//
// secondViewController.swift
//
import UIKit
class secondViewController: UIViewController {
#IBOutlet weak var test: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
self.test.text!=""
// Do any additional setup after loading the view.
}
override func viewWillAppear(_ animated: Bool) {
test.text = String(finalResult)
}
}
Screenshot:
Thanks.
Your problem is with the global variables. It seems from your code that you expect these three to reevaluate every time one of them changes:
var result = ""
var resultFinal = Float(result)
let finalResult = resultFinal!
For example, if you set resultFinal = 4, then finalResult will equal 4. However, those variables only evaluate once––the first time. You can simplify your use of these variables significantly. Replace these three with:
var result: Float?
Then, in ViewController:
class ViewController: UIViewController {
#IBOutlet weak var firstNumber: UITextField!
#IBOutlet weak var secondNumber: UITextField!
func getResult() -> Float {
guard let number1 = Float(firstNumber.text ?? "0") ?? 0
guard let number2 = Float(secondNumber.text ?? "0") ?? 0
return number1 + number2
}
#IBAction func submitSum(_ sender: Any) {
result = getResult()
}
}
Note: I simplified getResult and made it treat empty fields as 0.
In SecondViewController:
class SecondViewController: UIViewController {
#IBOutlet weak var test: UITextField!
override func viewWillAppear(_ animated: Bool) {
test.text = String(result ?? 0)
}
}
Note: self.test.text!="" doesn't really do anything, so I removed it.
I want to create a simple BMI calculator using height and weight and I am having trouble converting my UITextField strings to integers for the calculation.
Here's my working code:
import UIKit
class BMICalculator: UIViewController {
//MARK: Properties
#IBOutlet weak var weightField: UITextField!
#IBOutlet weak var heightField: UITextField!
#IBOutlet weak var solutionTextField: UILabel!
#IBAction func calcButton(_ sender: AnyObject) {
let weightInt = Int(weightField)
let heightInt = Int(heightField)
solutionTextField.text = weightInt/(heightInt*heightInt)
}
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
Anyone have any ideas? I tried searching for the solution but couldn't find anything specific to this issue.
Use this:
guard let text1 = weightField.text else {
return
}
guard let text2 = heightField.text else {
return
}
guard let weightInt = Int(text1) else {
return
}
guard let heightInt = Int(text2) else {
return
}
solutionTextField.text = weightInt /(heightInt*heightInt)
//Change your name for this outlet 'solutionTextField' to 'solutionLabel' since it is a UILabel not UITextField
The TextField only accepts a String, it wont take an Int.
Change this:
solutionTextField.text = weightInt/(heightInt*heightInt)
To this:
solutionTextField.text = String(weightInt/(heightInt*heightInt))
I don't think your code is working. To get the values out of your UITextFields and convert them to Ints, you'll need to pull them out of the '.text properties. Then, when you calculate the result, you'll need to convert it back to a string and set solutionTextField?.text equal to that result.
class BMICalculator: UIViewController {
//MARK: Properties
#IBOutlet weak var weightField: UITextField!
#IBOutlet weak var heightField: UITextField!
#IBOutlet weak var solutionTextField: UILabel!
#IBAction func calcButton(_ sender: AnyObject) {
let weightInt = Int((weightField?.text!)!)
let heightInt = Int((heightField?.text!)!)
let solution = weightInt!/(heightInt!*heightInt!)
solutionTextField?.text = "\(solution)"
}
override func viewDidLoad() {
super.viewDidLoad()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
Keep in mind that this code is very dangerous because you're not safely unwrapping optionals, but that's a different thread.
Hope this helps.
I want a stepper and label to reset to zero after my variable in another class is also reset. The variables reset but the stepper and label do not even after using a delegate.
View Controller:
class ViewController: UIViewController, CircleViewDelegate {
var colors = CircleView()
#IBOutlet weak var circleView1: CircleView!
#IBOutlet weak var redStepper: UIStepper!
#IBOutlet weak var redValue: UILabel!
#IBAction func stepperChange(sender: UIStepper)
{
circleView1.redd1 = Int(redStepper.value);
redValue.text = Int(sender.value).description;
}
func updateRedStepperValue(value: Double) {
redStepper.value = value
redValue.text = Int(colors.redd1.value).description;
}
override func viewDidLoad() {
super.viewDidLoad()
colors.delegate = self
}
}
CircleView:
protocol CircleViewDelegate
{
func updateRedStepperValue(value: Double)
func updateGreenStepperValue(value: Double)
func updateBlueStepperValue(value: Double)
}
class CircleView: UIView
{
var delegate: CircleViewDelegate?
var redd1 = 0
func updateValues()
{
if(redd1==Int(red1))
{
redd1=0;
delegate?.updateRedStepperValue(0.0)//
}
}
}
The problem is that your making a brand new instance of your CircleView.
let cycle = CircleView()
You need to set your delegate to your current working instance.
To do so, you should replace your assignment in your viewDidLoad with the following:
override func viewDidLoad() {
super.viewDidLoad()
let app = UIApplication.sharedApplication().delegate! as! AppDelegate
if let viewControllers = app.window?.rootViewController?.childViewControllers {
viewControllers.forEach { vc in
if let cont = vc as? CircleView {
cont.delegate = self
}
}
}
}
Here's an article with project files.
Hey guys I need some one to help me finish my app, I need to finish it before Dec 15. I'm making a Tip Calculator Project in Swift2 and It must have a settings view where I select the default tip rate. I have some issues with passing data, when I select a default tip percentage it doesn't change in the View Controller, also I want to make the app remember the default rate when I close the app and reopened. I will really appreciate that some one corrects my code and test it. Im new in this, below is the code of the two ViewControllers and a screenshot of the Main.Storyboard (Image 1) (ViewController Screenshot)
My apologies for my bad English, is not my native language
ViewController
import UIKit
class ViewController: UIViewController {
//Inputs
#IBOutlet weak var amountTextField: UITextField!
//Labels
#IBOutlet weak var TipPercentageLabel: UILabel!
#IBOutlet weak var numberOfPersonLabel: UILabel!
#IBOutlet weak var tipAmountLabel: UILabel!
#IBOutlet weak var totalBillLabel: UILabel!
#IBOutlet weak var billPerPersonLabel: UILabel!
//Slider & Stepper
#IBOutlet weak var tipSlider: UISlider!
#IBOutlet weak var personsStepper: UIStepper!
//Variables
var tipPercentage = 0.20
var numberOfPerson:Int = 1
let numberFormatter:NSNumberFormatter = NSNumberFormatter()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
tipAmountLabel.text = "$0.00"
totalBillLabel.text = "Bill Total"
billPerPersonLabel.text = "$0.00"
TipPercentageLabel.text = "20.0%"
numberOfPersonLabel.text = "1"
self.amountTextField.becomeFirstResponder()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func setupContainer() {
tipSlider.minimumValue = 0
tipSlider.maximumValue = 100
tipSlider.value = 20
tipSlider.addTarget(self, action: "sliderTipChanged:", forControlEvents: .ValueChanged)
personsStepper.minimumValue = 1
personsStepper.maximumValue = 30
personsStepper.value = 1
personsStepper.addTarget(self, action: "sliderPersonChanged:", forControlEvents: .ValueChanged)
amountTextField.text = ""
refreshCalculation()
}
#IBAction func OnEditingFieldBill(sender: AnyObject) {
refreshCalculation()
}
func refreshCalculation() {
numberFormatter.numberStyle = NSNumberFormatterStyle.DecimalStyle
if let amount = numberFormatter.numberFromString(amountTextField.text!) as? Double {
let tipAmount = amount * tipPercentage
let totalBill = amount + tipAmount
let billPerPerson = totalBill / Double(numberOfPerson)
numberFormatter.numberStyle = NSNumberFormatterStyle.CurrencyStyle
tipAmountLabel.text = numberFormatter.stringFromNumber(tipAmount)
totalBillLabel.text = numberFormatter.stringFromNumber(totalBill)
billPerPersonLabel.text = numberFormatter.stringFromNumber(billPerPerson)
} else {
tipAmountLabel.text = "-"
totalBillLabel.text = "-"
billPerPersonLabel.text = "-"
}
numberFormatter.numberStyle = NSNumberFormatterStyle.PercentStyle
numberFormatter.minimumFractionDigits = 1
numberFormatter.maximumFractionDigits = 1
TipPercentageLabel.text = self.numberFormatter.stringFromNumber(tipPercentage)
numberOfPersonLabel.text = "\(numberOfPerson)"
}
#IBAction func sliderTipChanged(sender: AnyObject) {
tipPercentage = Double(round(tipSlider.value)) / 100
refreshCalculation()
}
#IBAction func StepperPersonChanged(sender: AnyObject) {
numberOfPerson = Int(round(personsStepper.value))
refreshCalculation()
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if let id = segue.identifier {
if id == "show settings" {
if let SettingsViewController = segue.destinationViewController as? SettingsViewController {
}
}
}
}
}
Settings View Controller
import UIKit
class SettingsViewController: UIViewController {
#IBOutlet weak var tipControl: UISegmentedControl!
var tipRates:Double?
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func DefaultRate(sender: AnyObject) {
var tipRate = [5, 10, 15, 20, 25, 30]
var tipRates = Double(tipRate[tipControl.selectedSegmentIndex])
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if let id = segue.identifier {
if id == "goBackToViewController" {
if let ViewController = segue.destinationViewController as? ViewController {
if let tip = tipRates {
ViewController.tipPercentage = tip/100
}
}
}
}
---- Edit from comments ----
I think the reason it is not updating as you would like is due to a minor error with this line.
var tipRates = Double(tipRate[tipControl.selectedSegmentIndex])
Inside of your DefaultRate action function for the UISegmentedControl
Using var is a redeclaration of the same variable name, thus what you are trying to pass in the prepareForSegue is an empty variable.
This function should be changed to:
#IBAction func DefaultRate(sender: AnyObject) {
var tipRate = [5, 10, 15, 20, 25, 30]
tipRates = Double(tipRate[tipControl.selectedSegmentIndex])}
Hopefully this will now solve the error.
---- End Edit ----
From what I can see in the viewDidLoad function of your viewController, you are setting the tip label, and not updating the value based on the variable var tipPercentage.
TipPercentageLabel.text = "20.0%"
is setting the value display to always be 20.0%, you could use this here.
var tipDisplay = tipPercentage * 100
TipPercentageLabel.text = "\(tipDisplay)%"
This should update the displayed value in the label, however you never call on your other functions to recalculate the amount etc.
Thus you should also be calling on
func setupContainer()
or
func refreshCalculation()
within your ViewDidLoad().
In terms of remembering the default value when the app is closed you should look into using NSUserDefaults.
Some information regarding NSUserDefaults can be found here, which explains implementing small amounts of saved data and can be implemented in your case quite simply.
Hey guys I need some help here with my code, please take a look to the images to see what I see. I'm making a Tip Calculator Project in Swift and I must have a settings view where I select the default tip rate. I have some errors and I must fix that as soon as posible. I will really appreciate that some one corrects my code and test it. Below is the code of the two ViewControllers, I did not post the image of the Settings View Controller because the website does not let me post more than two links until I get more reputation.
The error in Xcode:
Storyboard: Check the images I have some errors at the first lines.
import UIKit
class ViewController: UIViewController, SettingDelegate {
// Inputs
#IBOutlet weak var amountTextField: UITextField!
//Labels
#IBOutlet weak var TipPercentageLabel: UILabel!
#IBOutlet weak var numberOfPersonLabel: UILabel!
#IBOutlet weak var tipAmountLabel: UILabel!
#IBOutlet weak var totalBillLabel: UILabel!
#IBOutlet weak var billPerPersonLabel: UILabel!
//Slider & Stepper
#IBOutlet weak var tipSlider: UISlider!
#IBOutlet weak var personsStepper: UIStepper!
//Variables
var tipPercentage : Double = NSUserDefaults.standardUserDefaults().doubleForKey("DefaultTipRate") ?? 0.20
var numberOfPerson:Int = 1
let numberFormatter:NSNumberFormatter = NSNumberFormatter()
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
tipAmountLabel.text = "$0.00"
totalBillLabel.text = "Bill Total"
billPerPersonLabel.text = "$0.00"
TipPercentageLabel.text = "20.0%"
numberOfPersonLabel.text = "1"
self.amountTextField.becomeFirstResponder()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func setupContainer() {
tipSlider.minimumValue = 0
tipSlider.maximumValue = 100
tipSlider.value = 20
tipSlider.addTarget(self, action: "sliderTipChanged:", forControlEvents: .ValueChanged)
personsStepper.minimumValue = 1
personsStepper.maximumValue = 30
personsStepper.value = 1
personsStepper.addTarget(self, action: "sliderPersonChanged:", forControlEvents: .ValueChanged)
amountTextField.text = ""
refreshCalculation()
}
#IBAction func OnEditingFieldBill(sender: AnyObject) {
refreshCalculation()
}
func refreshCalculation() {
numberFormatter.numberStyle = NSNumberFormatterStyle.DecimalStyle
if let amount = numberFormatter.numberFromString(amountTextField.text!) as? Double {
let tipAmount = amount * tipPercentage
let totalBill = amount + tipAmount
let billPerPerson = totalBill / Double(numberOfPerson)
numberFormatter.numberStyle = NSNumberFormatterStyle.CurrencyStyle
tipAmountLabel.text = numberFormatter.stringFromNumber(tipAmount)
totalBillLabel.text = numberFormatter.stringFromNumber(totalBill)
billPerPersonLabel.text = numberFormatter.stringFromNumber(billPerPerson)
} else {
tipAmountLabel.text = "-"
totalBillLabel.text = "-"
billPerPersonLabel.text = "-"
}
numberFormatter.numberStyle = NSNumberFormatterStyle.PercentStyle
numberFormatter.minimumFractionDigits = 1
numberFormatter.maximumFractionDigits = 1
TipPercentageLabel.text = self.numberFormatter.stringFromNumber(tipPercentage)
numberOfPersonLabel.text = "\(numberOfPerson)"
}
#IBAction func sliderTipChanged(sender: UISlider) {
tipPercentage = Double(round(tipSlider.value)) / 100
refreshCalculation()
}
#IBAction func StepperPersonChanged(sender: UIStepper) {
numberOfPerson = Int(round(personsStepper.value))
refreshCalculation()
}
override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
if let SettingsViewController = segue.destinationViewController as?SettingsViewController {
SettingsViewController.delegate = self
refreshCalculation()
}
}
}
The SettingsViewController below:
import UIKit
protocol SettingDelegate {
func tipPercentageChanged(newValue : Double)
}
class SettingsViewController: UIViewController {
var destName : String!
var delegate : SettingDelegate?
#IBOutlet weak var tipControl: UISegmentedControl!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
#IBAction func DefaultRate(sender: AnyObject) {
var tipRates = [0.05, 0.10, 0.15, 0.20, 0.25, 0.30]
let tipRate = tipRates[tipControl.selectedSegmentIndex]
delegate?.tipPercentageChanged(tipRate)
NSUserDefaults.standardUserDefaults().setDouble(tipRate, forKey: "DefaultTipRate")
NSUserDefaults.standardUserDefaults().synchronize()
}
/
For your first error:
When a viewController conforms to a protocol, it needs to implements the methods the protocol implements. In your case, define you should have
func tipPercentageChanged(newValue : Double) {
//save the new value here
}
The first error should go away.
It looks like you are presenting the SettingsViewController using a modal transition, so you can use
self.dismissViewControllerAnimated(true, completion: {})