点击 UILabel (Swift) 时如何显示 UIPickerView？

Question

我的应用程序在启动时显示某物的价格，并且我隐藏了货币列表。当用户点击价格时，我想让它显示下面隐藏的货币列表，然后在选择一种后再次隐藏它们。不知道怎么办，没有找到任何 Swift 轻击手势识别器的代码？我是你可以做类似 priceLabel.isTappedUp = blah blah 的事情，几年前，也许它是 Objec C。有什么想法吗？

代码如下：

class ViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {

let baseURL = "https://apiv2.bitcoinaverage.com/indices/global/ticker/BTC" // API
let currencyArray = ["AUD", "BRL","CAD","CNY","EUR","GBP","HKD","IDR","ILS","INR","JPY","MXN","NOK","NZD","PLN","RON","RUB","SEK","SGD","USD","ZAR"] // List of currencies
let currencySymbolArray = ["$", "R$", "$", "¥", "€", "£", "$", "Rp", "₪", "₹", "¥", "$", "kr", "$", "zł", "lei", "₽", "kr", "$", "$", "R"]           // Currency symbols
var currencySelected = ""
var finalURL = ""


// Pre-setup IBOutlets
@IBOutlet weak var priceLabel: UILabel!
@IBOutlet weak var currencyPicker: UIPickerView!



override func viewDidLoad() {
    super.viewDidLoad()

    currencyPicker.delegate = self
    currencyPicker.dataSource = self

    currencyPicker.selectRow(5, inComponent:0, animated:false) // Select default currency choice to £

    // Print out the default row price 

    finalURL = baseURL + currencyArray[5]
    print(finalURL)
    currencySelected = currencySymbolArray[5]
    getBitcoinData(url: finalURL)

    currencyPicker.isHidden = true


    priceLabel.isUserInteractionEnabled = true

}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()

}



// Number of columns

func numberOfComponents(in pickerView: UIPickerView) -> Int {
    return 1
}
// Number of rows

func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    return currencyArray.count // Number of rows = the amount in currency array
}

// Row Title

func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
   return currencyArray[row]
}

func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {

    finalURL = baseURL + currencyArray[row]
    print(finalURL)
    currencySelected = currencySymbolArray[row]
    getBitcoinData(url: finalURL)
}

Answer 1

你可以试试手势

    let tapRound = UITapGestureRecognizer(target: self, action: #selector(self.handleTap(_:)))

    priceLabel.isUserInteractionEnabled = true

    priceLabel.addGestureRecognizer(tapRound)

//

@objc func handleTap(_ sender: UITapGestureRecognizer? = nil)
{
    self.currencyPicker.isHidden = false

}

Answer 2

您可以使用 UIPickerView 作为 UITextField 的 inputView，但使用 UITapGestureRecognizer 并保留 UILabel，定义以下变量：

var currencyPicker = UIPickerView()
var textField : UITextField!

然后将手势添加到viewDidLoad中的标签：

    let tapGesture = UITapGestureRecognizer(target: self, action: #selector(displayPickerView))
    tapGesture.numberOfTapsRequired = 1
    priceLabel.addGestureRecognizer(tapGesture)

最后添加手势处理程序来显示选择器，此函数将创建一个隐藏的 UITextField 个：

@objc private func displayPickerView(){

    if  textField == nil {

        self.textField = UITextField(frame:.zero)
        textField.inputView = self.currencyPicker
        self.view.addSubview(textField)

    }

    textField.becomeFirstResponder()

}

如果对你有帮助，请告诉我。

点击 UILabel (Swift) 时如何显示 UIPickerView？

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