ios - 在 View 选择器中选择状态，转到新屏幕

Question

我正在使用 Swift 在 XCode 中编写一个应用程序，目前我在该应用程序上有一个列表选择器。我希望用户能够从选择器 View 中选择一个状态，这会将他们带到一个新屏幕(专为该特定状态设计)。

用户界面:

Answer 1

方法一:

注意:如果您有一个必须自定义的 View Controller ，则可以使用它...

---

试试这个:

第 1 步:在您的 View Controller 上添加此变量:

var chosenState = String()

第 2 步:将此函数添加到 View Controller:

override func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int){
chosenState = yourPickerData[row] // yourPickerData = your state array
}

第 3 步:如果您有一个 segue 连接到按钮，请将其删除。在 Storyboard上做以下事情:

选择显示连接，点击segue并将其标识符设置为customSegue，如上图所示。

第 4 步:在 View Controller 的continue 按钮函数中，添加:

self.performSegueWithIdentifier("customSegue", sender: nil)

第 5 步:在您的 ViewController 中添加 prepareForSegue 方法:

 override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        if segue.identifier == "customSegue" {
            if let secondViewController = segue.destinationViewController as? secondViewController {
                secondViewController.customLabel.text = self.chosenState
// this is an example, but the view will contain the name of the chosen state by the time the button gets clicked... You can customize it...
            }
        }
    }

希望对您有所帮助!让我知道你的想法!

方法二:

注意:如果您在 Storyboard 中创建了更多View Controllers，将使用它。

---

试试这个:

界面:

第 1 步:转到您的 Storyboard 并在 pickerView 下方的场景中添加一个按钮，如下图所示，并确保您的 View Controller 的类实际上设置为 ViewController.swift:

第 2 步:打开 Assistant Editor 并通过 Ctrl+Click 连接按钮并拖动到 ViewController.swift，如如下所示:

连接类型:Action，随便命名。连接后，会出现:

@IBAction func continueButtonPressed(sender: AnyObject?){
//this is your continue button function
}

注意:出于教程目的，我将只使用 3 个状态!

第 3 步: 将三个 View Controllers(或任意多个)拖到场景中，然后添加三个(或任意多个)swift 文件为您的项目调用 StateName View Controller。将此代码添加到它们:

import UIKit

    class StateNameViewController: UIViewController{

    }

1: 2: 3: 4:

第 4 步:分配他们的类(class)，如下所示:

选择 storyboard 上的第一个 ViewController，转到 Identity Inspector 并将其类设置为 AlabamaViewController .其他 2 个也是如此。

第 5 步:然后为每个创建一个 segue，并将其标识符设置为 State Name Segue，如下所示:

第一个怎么做: 其他2:

第 6 步:使用如下代码连接 pickerView:

代码:

第 7 步:转到您的 ViewController 并添加以下内容:

class ViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {


    @IBOutlet weak var pickerView: UIPickerView!

    var pickerData = ["Alabama","Alaska","Kansas"]
    var chosenState = ""

    override func viewDidLoad() {
        super.viewDidLoad()

        pickerView.delegate = self
        pickerView.dataSource = self
        // Do any additional setup after loading the view, typically from a nib.
    }

第 8 步:在ViewController.swift 中，添加以下函数:

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

    // The data to return for the row and component (column) that's being passed in
    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
        return pickerData[row]
    }

    //Called when the user changes the selection...
    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
        chosenState = pickerData[row]
    }

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

    return 1
    }

第 9 步: 添加了代码的按钮函数:

@IBAction func continueButtonPressed(_ sender: AnyObject) {
     self.performSegue(withIdentifier: "\(chosenState)Segue", sender: nil)

}

预览 - 方法 2:

最后的ViewController.swift:

import UIKit

class ViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {


    @IBOutlet weak var pickerView: UIPickerView!

    var pickerData = ["Alabama","Alaska","Kansas"]
    var chosenState = ""

    override func viewDidLoad() {
        super.viewDidLoad()

        pickerView.delegate = self
        pickerView.dataSource = self
        // Do any additional setup after loading the view, typically from a nib.
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    @IBAction func continueButtonPressed(_ sender: AnyObject) {
         self.performSegue(withIdentifier: "\(chosenState)Segue", sender: nil)

    }


    // The number of columns of data


    // The number of rows of data
    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        return pickerData.count
    }

    // The data to return for the row and component (column) that's being passed in
    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
        return pickerData[row]
    }
    //Called when the user changes the selection...
    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
        chosenState = pickerData[row]
    }

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

    return 1
    }


}

就是这样!告诉我是否有帮助!