如何 return 在以编程方式创建的 UIPicker 委托中选择值

Question

我有一个 viewController，上面有一堆输入。其中有些是普通文本，但有些需要选择器输入。我决定将每个 PickerDelegate 和 PickerDataSource 的实现移动到一个单独的文件中，以使事情更清晰一些。数据正在出现，但在选择器的 select 上，我不知道如何让事件在我的 viewController 中触发。目前它只在 PickerDelete class.

中触发

一些基本的布局信息是

class MyClass: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {

let jobTypePickerValues = ["value1", "value2"]

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

// returns the # of rows in each component..
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    return jobTypePickerValues.count
}

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

func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int)
{
    //println("I want this in the view controller that set up the picker")
}

在显示选择器的视图控制器中，我有以下内容

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


    myClassSource = MyClass()
    pickerView = UIPickerView()
    pickerView.dataSource = myClassSource
    pickerView.delegate = myClassSource

    // set the input view of the job type to be a picker view
    textInput.inputView = pickerView
    textInput.text = jobTypePickerValues[0]
}

Answer 1

您需要创建一个自定义委托并在您创建 pickerView 的 ViewController 中实施。

protocol CustomPickerDelegate {
     func selectedItem(item: String)
}

现在在 MyClass 中创建此协议的实例并在 `ViewController``

中实现

class MyClass: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {

    let jobTypePickerValues = ["value1", "value2"]
    var delegate: CustomPickerDelegate?
    .. Other code and methods

    func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
         delegate?. selectedItem(jobTypePickerValues[row])
    }
}

现在在viewDidLoad中设置委托并实现协议的方法。

class ViewController: UIViewController, CustomPickerDelegate {

     override func viewDidLoad() {
         super.viewDidLoad()

         myClassSource = MyClass()
         myClassSource.delegate = self
         pickerView = UIPickerView()
         pickerView.dataSource = myClassSource
         pickerView.delegate = myClassSource

         // set the input view of the job type to be a picker view
         textInput.inputView = pickerView
         textInput.text = jobTypePickerValues[0]
     }

      func selectedItem(item: String) {

          textInput.text = item
      }
}

如何 return 在以编程方式创建的 UIPicker 委托中选择值

How to return selected value in UIPickerDelegate when created programatically

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