根据从 UIPickerView 选择的值打开新的视图控制器页面 (Swift 4)

Question

我想在我的应用程序中添加一个功能，用户必须从 UIPickerView 中选择一个类别，然后单击按钮，程序将打开从 UI选择器视图。例如，如果在 UIPickerView 上选择的选项之一是 "About Page"，我希望有一个程序可以在单击按钮时打开 "About Page"。

这就是 UI 的样子。

但不是状态 - 我会有类别，我不确定如何在 UIPickerView 中设置值并打开特定视图。

Answer 1

实施UIPickerViewDelegate方法并给每个VC一个故事板标识符

var lastId:String?

var ids = ["secondVC","thirdVC"] // picker data source and identifier names 

func pickerView(_ pickerView: UIPickerView, 
        didSelectRow row: Int, 
         inComponent component: Int) {
   lastId = ids[row]
}

@IBAction func goClicked(_ sender:UIButton) {
    if let id = lastId {
      let vc = storyboard.instantiateViewController(withIdentifier:id)!
      self.present(vc, animated: true, completion: nil) // or push
    }
    else {
      // select a vc alert
    }
}

Answer 2

如果您想以编程方式创建选取器视图（我最推荐这种方法），此解决方案应该适合您：

class MyViewController : UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {
    
    let pickerView = UIPickerView()
    let titles = ["view1", "view2"]
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        view.backgroundColor = .white
        
        pickerView.delegate = self
        pickerView.dataSource = self
        
        view.addSubview(pickerView)
    }
    
    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        return 2
    }
    
    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
        return titles[row]
    }
    
    func numberOfComponents(in pickerView: UIPickerView) -> Int {
        return 1
    }
    
    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
        if row == 0 {
            let view1 = viewController1()
            self.present(view1, animated: true, completion: nil)
        }
        if row == 1 {
            let view2 = viewController2()
            self.present(view2, animated: true, completion: nil)
        }
    }
    
}

class viewController1 : UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        view.backgroundColor = UIColor.white
    }
}

class viewController2 : UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        view.backgroundColor = UIColor.white
    }
}

希望这对你也有用 ;)

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