根据来自其他文本字段的输入计算并返回文本字段中的值

Question

所以，我要做的是将值输入到文本字段 1 和文本字段 2 和文本字段 3 应该自动计算并返回结果。在我的主板中，我已经添加了editingchanged 并连接了@IBAction。该功能仅在我按下键盘上的“Backspace”按钮时才起作用。我的 TableViewController 功能如下

类 SecondTableViewController: UITableViewController, UITextFieldDelegate {

//identifier is saving 


@IBOutlet weak var Done: UIBarButtonItem!


var watts: Double = 0.0
var hours: Double = 0.0
var result: Double = 0.0
var hoursfromfunction: Double = 0.0
var wattsfromfunction: Double = 0.0
var receivedData = " "

override func viewDidLoad() {
    super.viewDidLoad()
    // Uncomment the following line to display an Edit button in the navigation bar for this view controller.
    // self.navigationItem.rightBarButtonItem = self.editButtonItem()

}

override func numberOfSections(in tableView: UITableView) -> Int {
    return 2

}

override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
    return 1

}


override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
    let cell = tableView.dequeueReusableCell(withIdentifier: "saving", for: indexPath) as! SaveTableViewCell


    if (indexPath.section == 0) {
        cell.WattsOutput.placeholder = "Enter Watts. Can be found on label"
        cell.WattsOutput.keyboardType = UIKeyboardType.numbersAndPunctuation
        var textField100 = cell.WattsOutput
        textField100?.tag = 100
        textField100?.delegate = self
        //print ("Returned value is \(wattstext)")

        cell.HoursWeekOutput.placeholder = "Enter hours worked per week"
        cell.HoursWeekOutput.keyboardType = UIKeyboardType.numbersAndPunctuation
        var textField200 = cell.HoursWeekOutput
        textField200?.delegate = self
        textField200?.tag = 200

        var textField300 = cell.ResultTextField
        resultFieldChanged(textField300!)

        return cell
        }

    return cell
    }

func textFieldShouldReturn(_ textField: UITextField) -> Bool {

    if (textField.tag == 100){
        //print ("Should return is called and the value is \(textField.text!) W ")
        watts = Double(textField.text!)!
        calculatewatts(watts)
    }
    else if (textField.tag == 200) {
        //print ("Should return is called and the value is \(textField.text!) hours")
        hours = Double(textField.text!)!
        calculatehours(hours)
    }

    //resultFieldChanged(textField)

    return true
}


func calculatehours (_ arg: Double) -> Double {
    print ("The function calculateHours returns \(arg)")
    return arg
 }

func calculatewatts (_ arg: Double) -> Double {
    print("The function calculateWatts returns \(arg)")
    return arg
}


@IBAction func resultFieldChanged (_ textField: UITextField) {
    hoursfromfunction = calculatehours(hours)
    wattsfromfunction = calculatewatts(watts)
    result = hoursfromfunction * wattsfromfunction
    print ("Output of functions are \(hoursfromfunction) & \(wattsfromfunction)")

    textField.text? = "\(result)"
    print ("Result is \(result)")
}

所以，ResultTextField 只有在我选择实际的 TextField 并按下“退格键”时才会返回计算值

我将不胜感激。谢谢你。

Answer 1

CTRL + Drag你的textFields到你的代码并选择Action作为连接

将事件设置为Editing Changed

现在，在 IBAction 块中做你想做的事！

Answer 2

试试这个：

斯威夫特：

yourTextfield.addTarget(self, action: #selector(textFieldDidChange(textField:)), for: .editingChanged)

然后，实现回调函数：

func textFieldDidChange(textField: UITextField){

 if (textField.tag == 100){
    //print ("Should return is called and the value is \(textField.text!) W ")
    watts = Double(textField.text!)!
    calculatewatts(watts)
}
else if (textField.tag == 200) {
    //print ("Should return is called and the value is \(textField.text!) hours")
    hours = Double(textField.text!)!
    calculatehours(hours)
}


}