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

Question

错误：

类型“ GearViewController”不符合协议“ UIPickerViewDataSource”

根据Apple文档 ，UIPickerViewDataSource仅需要2种方法。 两者都包含在下面的代码中。 我认为语法是正确的。 （但可能不是）

类/控件声明和初始化。 （为清晰起见，删除了许多其他代码。如果需要，可以使用完整代码，我将进行编辑。只是想保持简短。）

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

这里有numberOfComponents，但是pickerView在哪里？

Answer 2

您实现的一种协议方法是错误的，该方法应为：

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

您已经实现了该方法，

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

改正它，您应该就很好了。

Answer 3

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