错误:键入“GearViewController”不符合协议“UIPickerViewDataSource”

Question

错误：

类型'GearViewController‘不符合协议'UIPickerViewDataSource’

基于苹果文档，UIPickerViewDataSource只需要两个必需的方法。这两者都包含在下面的代码中。我认为语法是正确的。(但很可能不是)

类/控件声明和init。(为了清晰起见，删除了许多其他代码。如果需要，我会编辑完整的代码。只是尽量保持简短。)

class  GearViewController: UIViewController, UITableViewDataSource, UITableViewDelegate, UIPickerViewDataSource, UIPickerViewDelegate{

@IBOutlet weak var pickerGearCategory: UIPickerView!

override func viewDidLoad() {

        super.viewDidLoad()

        pickerGearCategory.dataSource = self
        pickerGearCategory.delegate = self

    }

委托和数据源

  let gearCategoryPickerData = CategoryRepository.allCategories()
    //MARK: CategoryPicker- Delegates and data sources
    //MARK: CategoryPicker - Data Sources


    //Required
    func numberOfComponents(in pickerGearCategory: UIPickerView) -> Int {
        return 1
    }

    //Required
    func pickerGearCategory(pickerGearCategory: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        return gearCategoryPickerData.count
    }


    func pickerGearCategory(pickerGearCategory: UIPickerView,titleForRow row: Int, forComponent component: Int) -> String? {
        return gearCategoryPickerData[row].name
    }

Answer 1

您实现的协议方法之一是错误的，该方法应该是：

func pickerView(UIPickerView, numberOfRowsInComponent: Int) {
//Your implementation here
}

您已经将该方法实现为

func pickerGearCategory(pickerGearCategory: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
//Your implementation
}

更正一下，你就可以走了。

Answer 2

numberOfComponents在那里，但pickerView在哪里？

Answer 3

只需添加func pickerView(UIPickerView, numberOfRowsInComponent: Int)函数