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swift - 如何在一个视图控制器中使用多个 UIPickerViews

问题描述

我正在尝试在 1 个视图控制器中设置 2 个 UIPickerViews。我一直无法找到解决我的问题的资源。

我尝试按照 Diavel Rider 关于如何在一个视图控制器中使用 2 个 UIPickerView 的答案进行操作？. 我从中得到了一些错误。我也尝试过添加标签，但未能成功。我正在使用 Swift 4。

这是我的视图控制器的代码：

import UIKit

class FirstViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {

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

    func pickerView(_ foodTypeUIPickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        var countrows : Int = nutritionPickerData.count
        if pickerView == foodTypeUIPickerView { **[Error Here: "Binary operator '==' cannot be applied to operands of type '_' and 'UIPickerView'"]**
            countrows = self.foodTypePickerData.count
        }
        return countrows
    }

    func pickerView(_ foodTypeUIPickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
        if pickerView == nutritionUIPickerView { **[Error Here: "Binary operator '==' cannot be applied to operands of type '_' and 'UIPickerView'"]**
            let titleRow = nutritionPickerData[row]
            return titleRow
        } else if pickerView == foodTypeUIPickerView { **[Error Here: "Binary operator '==' cannot be applied to operands of type '_' and 'UIPickerView'"]**
            let titleRow = foodTypePickerData[row]
            return titleRow
        }

        return ""

    }

    @IBOutlet weak var nutritionUIPickerView: UIPickerView!

    @IBOutlet weak var foodTypeUIPickerView: UIPickerView!

    var nutritionPickerData = ["Protein", "Fiber", "Iron", "Fat", "Sodium", "Calcium/Vitamin D", "Energy", "Carbohydrates", "Cholestorol"]
    var foodTypePickerData = ["Fruits", "Vegetables", "Legumes and Beans", "Grain", "Meat", "Dairy"]

    @IBAction func submitUIButton(_ sender: Any) {
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        self.nutritionUIPickerView.delegate = self
        self.nutritionUIPickerView.dataSource = self

        self.foodTypeUIPickerView.delegate = self
        self.foodTypeUIPickerView.dataSource = self

    }


}

我需要在 1 个视图控制器中使用 2 个选择器视图。我该怎么做呢？

标签： swiftuipickerview

解决方案

您正在引用一个名为 的不存在的变量pickerView。您应该更新参数名称pickerView以避免出现问题。

func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    if pickerView == foodTypeUIPickerView {
        return self.foodTypePickerData.count
    } else {
        return self. nutritionPickerData.count
    }
}

对其他委托/数据源方法进行类似的更改。

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