Ios UIPickerView仅显示两条灰线

这是我第一次使用stackoverflow，我对编程非常陌生，所以如果这是一个糟糕的问题，请原谅我。无论如何，我试着创建一个UIPickerView，程序运行成功，但只显示了两条水平灰线。我将包括一些代码和图像。先谢谢你

let UIPicker: UIPickerView = UIPickerView()
    
    UIPicker.delegate = self as? UIPickerViewDelegate
    UIPicker.dataSource = self as? UIPickerViewDataSource
    self.view.addSubview(UIPicker)
    UIPicker.center = self.view.center
    
    class LanguageNativeViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {
        
        let dataArray = ["English", "Spanish", "French", "German", "Italian", "Portuguese", "Russian", "Japanese"]
        
        func numberOfComponents(in pickerView: UIPickerView) -> Int {
           return 1
        }
        func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
           return dataArray.count
        }
        func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
           let row = dataArray[row]
           return row
        }

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供将来参考。。。在这里提问时，最好发布您正在处理的实际代码

由于我们不知道您将代码放在何处，请尝试一下：

class LanguageNativeViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {
    
    let dataArray = ["English", "Spanish", "French", "German", "Italian", "Portuguese", "Russian", "Japanese"]

    let UIPicker: UIPickerView = UIPickerView()

    override func viewDidLoad() {
        super.viewDidLoad()

        UIPicker.delegate = self
        UIPicker.dataSource = self
        self.view.addSubview(UIPicker)
        UIPicker.center = self.view.center
        
    }
    
    func numberOfComponents(in pickerView: UIPickerView) -> Int {
        return 1
    }
    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        return dataArray.count
    }
    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
        let row = dataArray[row]
        return row
    }

}

结果:

作为旁注，变量和属性使用小写：

let uiPicker: UIPickerView = UIPickerView()

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您的三个委托方法是否被调用过？您的代码片段看起来是正确的，但在屏幕截图中LanguageNativeViewController既不是UIPickerViewDelegate也不是UIPickerViewDataSource@WongWray非常感谢，我修好了，它成功了。作为一个努力想弄明白这一点的初学者，我不能感谢你，因为我很高兴它成功了——很乐意帮忙。非常感谢你的帮助