为什么UIPickerView显示空列表

问题描述 投票:0回答:1

我创建了两个UIPickerView并为每个来源声明。单击Label后,用户应查看所选UIPickerView的值

override func viewDidLoad() {
        super.viewDidLoad()
        print(monthBoolLabel)
        monthPickerView.dataSource = self
        monthPickerView.delegate = self
        monthPickerView.isHidden = true

        freeDayPickerView.dataSource = self
        freeDayPickerView.delegate = self
        freeDayPickerView.isHidden = true

        let tapMonth = UITapGestureRecognizer(target: self, action: #selector(tapOnMonth(gestureReconizer:)))
        monthLabel.addGestureRecognizer(tapMonth)
        monthLabel.isUserInteractionEnabled = true

        let tapFreeDay = UITapGestureRecognizer(target: self, action: #selector(tapOnFreeDay(gestureReconizer:)))
        freedayLabel.addGestureRecognizer(tapFreeDay)
        freedayLabel.isUserInteractionEnabled = true


        let tapView = UITapGestureRecognizer(target: self, action: #selector(backgroundViewTapped))
        view.addGestureRecognizer(tapView)
}

我声明了用户点击标签时检测到的功能:

@objc func tapOnMonth(gestureReconizer: UITapGestureRecognizer) {
        print("*")
        monthPickerView.isHidden = false
        monthBoolLabel = true
        freedayBoolLabel = false

    }

    @objc func tapOnFreeDay(gestureReconizer: UITapGestureRecognizer) {
        print("*")
        freeDayPickerView.isHidden = false
        freedayBoolLabel = true
        monthBoolLabel = false
    }

我也扩展了我的ViewController

extension HomePageViewController: UIPickerViewDelegate, UIPickerViewDataSource {

    func numberOfComponents(in pickerView: UIPickerView) -> Int {
        return 1
    }

    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        if freedayBoolLabel == true {
            return freeDaySource.count
        }
        else if monthBoolLabel == true{
            return monthSource.count
        }
        else {
            return 0
        }
    }


    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
        if freedayBoolLabel == true {
            freedayLabel.text = freeDaySource[row]
        }
        else if monthBoolLabel == true{
            monthLabel.text = monthSource[row]
        }

    }

    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
        if freedayBoolLabel == true {
            return freeDaySource[row]
        }
        else if monthBoolLabel == true{
            return monthSource[row]
        }
        else {
            return ""
        }
    }

}

无论UILabel用户点击哪个,列表始终为空

ios swift uipickerview
1个回答
2
投票

点击标签后需要重新加载选取器视图。

@objc func tapOnMonth(gestureReconizer: UITapGestureRecognizer) {
    print("*")
    monthPickerView.isHidden = false
    monthBoolLabel = true
    freedayBoolLabel = false
    monthPickerView.reloadAllComponents() // add this
}

在另一个中做出类似的改变。

仅供参考 - 您只需要一个选择器视图,而不是两个,因为您一次只显示一个。

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