显示空灰色框的 UIPickerView Swift

Question

我没有很多代码，所以我不妨复制它。

class ViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource{

    var buildings = ["BankBuilding", "Cinema" , "CornerShop", "Greg's House"]

    @IBOutlet weak var buildText: UITextField!

    var buildPickers:UIPickerView = UIPickerView()

    override func viewDidLoad() {
        super.viewDidLoad()

        buildPickers = UIPickerView()
        buildPickers.delegate = self
        buildPickers.hidden = true;
        buildText.inputView = buildPickers
        buildText.text = buildings[0]        
    }

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

    func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int{
        println("Count: \(buildings.count)")
        return buildings.count
    }

    func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String! {
        println("creating title: \(buildings[row])")
        return buildings[row]
    }

    func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int)
    {
        println("Selected: \(buildings[row])")
        buildText.text = buildings[row]
        buildPickers.hidden = true;
    }

    func textFieldShouldBeginEditing(textField: UITextField) -> Bool {
        buildPickers.hidden = false
        return false
    }
}

打印语句正确。对于 numberOfRows... 和 titleForRow 它正在打印正确的字符串。

但是 didSelectRow 没有打印，因为，好吧，我不能连续 select。

这是我得到的：

您可以忽略背景中的 Google 地图，它不会干扰选择器视图并且只是在 StoryBoard 中设置。

当我点击 textField 但从不显示任何内容时出现灰色 window。但印刷声明另有说明。

有人知道为什么会这样吗？

Answer 1

只需在您的 viewDidLoad 方法中添加这一行：

buildPickers.dataSource = self

您的代码将是：

override func viewDidLoad() {
    super.viewDidLoad()

    buildPickers = UIPickerView()
    buildPickers.delegate = self
    buildPickers.dataSource = self
    buildPickers.hidden = true;
    buildText.inputView = buildPickers
    buildText.text = buildings[0]        
}

它会显示你的数据。

更新：

它没有显示，因为您将它设置为隐藏在您的 viewDidLoad 中。

只需从您的代码中删除这一行：

buildPickers.hidden = true

这是您的工作代码：

import UIKit

class ViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource, UITextFieldDelegate{

    var buildings = ["BankBuilding", "Cinema" , "CornerShop", "Greg's House"]

    @IBOutlet weak var buildText: UITextField!

    var buildPickers:UIPickerView = UIPickerView()

    override func viewDidLoad() {
        super.viewDidLoad()

        buildPickers = UIPickerView()
        buildPickers.delegate = self
        buildPickers.hidden = true
        buildText.delegate = self        //set delegate for textField
        buildText.inputView = buildPickers
        buildText.text = buildings[0]
    }

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

    func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int{
        println("Count: \(buildings.count)")
        return buildings.count
    }

    func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String! {
        println("creating title: \(buildings[row])")
        return buildings[row]
    }

    func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int)
    {
        println("Selected: \(buildings[row])")
        buildText.text = buildings[row]
        buildPickers.hidden = true;
    }


    //this method will call when you click on textField
    func textFieldShouldBeginEditing(textField: UITextField) -> Bool {
        buildPickers.hidden = false
        return true
    }
}

Answer 2

是否在文本字段上设置了委托？您是否收到用于取消隐藏选择器的回调？

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