在Xcode/Swift中实现替换和插入按钮

Question

我是xCode的新手，对实现替换按钮和插入按钮的以下两件事感到困惑。有人能帮忙吗当你按下"替换"按钮，选择器中选择的项目应替换为文本字段的内容(如果为空文本字段中没有任何内容(。当您按下"插入"时，文本字段的内容应添加到选择器，在当前选择的项目之后，以及新添加的项目，应在选择器中显示为所选项目(因此，以前所选的项目将直接位于选择器的显示上点(。

class ViewController: UIViewController {
@IBOutlet weak var countryTextField: UITextField!
@IBOutlet weak var selectButton: UIButton!
@IBOutlet weak var replaceButton: UIButton!
@IBOutlet weak var insertButton: UIButton!
let countries = ["USA", "MEXICO", "CANADA"]
var pickerView = UIPickerView()
override func viewDidLoad() {
super.viewDidLoad()
pickerView.delegate = self
pickerView.dataSource = self

countryTextField.inputView = pickerView
countryTextField.textAlignment = .center
}
}
extension ViewController: UIPickerViewDelegate, UIPickerViewDataSource {

func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return countries.count
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
return countries[row]
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
countryTextField.text = countries[row]
countryTextField.resignFirstResponder()

}

}

Answer 1

从xib为按钮创建@IBAction并相应添加条件。它看起来像这些-

@IBAction func insertAction(sender: UIButton){
// write code for insert
}
@IBAction func replaceAction(sender: UIButton){
// write code for replace
}