Question

我收到此错误：/Users/natumyers/Desktop/proj/SignUp2ViewController.swift:11:7：类型'SignUp2ViewController'不符合协议'UIPickerViewDataSource'。我正在学习本教程http://codewithchris.com/uipickerview-example/，但我有一个与默认控制器分开的视图控制器。

import UIKit

class SignUp2ViewController: UIViewController, UIPickerViewDelegate, UIPickerViewDataSource {

    @IBOutlet weak var signuplabel: UITextField!

    var labelText = String()

    @IBOutlet weak var focusPicker: UIPickerView!
    var focusPickerData: [String] = [String]()

    override func viewDidLoad() {

        super.viewDidLoad()

        // Connect data:
        self.focusPicker.delegate = self
        self.focusPicker.dataSource = self

        focusPickerData = ["type1","type2","type3","type4"]

        signuplabel.text = labelText
    }

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

解决方案

这些功能是实现这一目标的关键。我补充说：

// The number of columns of data
    func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
        return 1
    }

// The number of rows of data
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    return focusPickerData.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 focusPickerData[row]
}

在didReceiveMemoryWarning函数之后。

Answer 1

您的视图控制器不符合UIPickerViewDataSource协议。您需要实现这两个必需的方法：

numberOfComponentsInPickerView(_:)
pickerView(_:numberOfRowsInComponent:)

数据源为选择器视图提供组件数量和每个组件中的行数，以显示选取器视图数据。这个协议中的两种方法都是必需的。

https://developer.apple.com/library/prerelease/ios/documentation/iPhone/Reference/UIPickerViewDataSource_Protocol/index.html#//apple_ref/occ/intfm/UIPickerViewDataSource/numberOfComponentsInPickerView:

尝试设置UIPickerView的数据源时出错

1 个答案: