iOS中如何将两个PickerView分别与对应Label关联显示选中内容？

这个问题的核心是你当前的代理方法没有区分触发事件的是哪一个PickerView，导致不管操作哪个，两个Label都会被设置成相同内容。我们只需要在代理回调里判断PickerView实例，再给对应的Label赋值就能解决。

步骤1：确保第二个Label的IBOutlet已正确连接 #

首先确认第二个Label已经通过Storyboard/XIB绑定到ViewController，添加对应的IBOutlet属性：

@IBOutlet weak var valuetype2: UILabel!

（别忘了同时确认picker1和picker2的IBOutlet也已正确连接哦）

步骤2：修改didSelectRow代理方法 #

在这个回调里，我们通过pickerView参数判断当前操作的是哪个选择器，然后针对性地更新Label内容：

func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
    let selectedText = pickerData[row]
    if pickerView == picker1 {
        valuetype1.text = selectedText
    } else if pickerView == picker2 {
        valuetype2.text = selectedText
    }
}

或者用更简洁的switch写法也可以：

func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
    let selectedText = pickerData[row]
    switch pickerView {
    case picker1:
        valuetype1.text = selectedText
    case picker2:
        valuetype2.text = selectedText
    default:
        break
    }
}

步骤3：初始化时设置默认内容（可选但推荐） #

为了避免页面刚加载时Label为空，建议在viewDidLoad里给两个Label设置默认选中行的内容：

override func viewDidLoad() {
    super.viewDidLoad()
    self.picker1.delegate = self
    self.picker1.dataSource = self
    self.picker2.delegate = self
    self.picker2.dataSource = self
    pickerData = ["Годы", "Месяцы", "Недели", "Дни", "Часы", "Минуты"]
    
    // 设置初始显示的默认内容
    valuetype1.text = pickerData[0]
    valuetype2.text = pickerData[0]
}

完整修改后的代码 #

@IBOutlet weak var valuetype1: UILabel!
@IBOutlet weak var valuetype2: UILabel!
@IBOutlet weak var picker1: UIPickerView!
@IBOutlet weak var picker2: UIPickerView!

var pickerData: [String] = [String]()

override func viewDidLoad() {
    super.viewDidLoad()
    self.picker1.delegate = self
    self.picker1.dataSource = self
    self.picker2.delegate = self
    self.picker2.dataSource = self
    pickerData = ["Годы", "Месяцы", "Недели", "Дни", "Часы", "Минуты"]
    
    // 初始化默认显示内容
    valuetype1.text = pickerData[0]
    valuetype2.text = pickerData[0]
}

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

func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    return pickerData.count
}

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

func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
    let selectedContent = pickerData[row]
    // 判断当前操作的PickerView实例
    switch pickerView {
    case picker1:
        valuetype1.text = selectedContent
    case picker2:
        valuetype2.text = selectedContent
    default:
        break
    }
}

这样修改后，picker1的选中内容会独立显示在valuetype1中，picker2的选中内容会显示在valuetype2中，两个选择器的操作就互不影响了。

内容的提问来源于stack exchange，提问作者Ivan Kisin