swift选取器未选择项目

import UIKit

class ViewController: UIViewController, UIPickerViewDataSource, UIPickerViewDelegate {
    
    let pickerView = UIPickerView()
    let data = ["Option 1", "Option 2", "Option 3"]
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // 设置数据源和代理
        pickerView.dataSource = self
        pickerView.delegate = self
        
        // 添加选择器到视图
        view.addSubview(pickerView)
        
        // 设置选择器的约束
        pickerView.translatesAutoresizingMaskIntoConstraints = false
        NSLayoutConstraint.activate([
            pickerView.centerXAnchor.constraint(equalTo: view.centerXAnchor),
            pickerView.centerYAnchor.constraint(equalTo: view.centerYAnchor),
            pickerView.widthAnchor.constraint(equalToConstant: 200),
            pickerView.heightAnchor.constraint(equalToConstant: 200)
        ])
    }
    
    // 返回选择器的列数
    func numberOfComponents(in pickerView: UIPickerView) -> Int {
        return 1
    }
    
    // 返回每列的行数
    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        return data.count
    }
    
    // 返回每行的标题
    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
        return data[row]
    }
    
    // 处理用户选择事件
    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
        print("Selected row: \(row), value: \(data[row])")
    }
}