錯誤：類型“ GearViewController”不符合協議“ UIPickerViewDataSource”

Question

錯誤：

類型“ GearViewController”不符合協議“ UIPickerViewDataSource”

根據Apple文檔 ，UIPickerViewDataSource僅需要2種方法。 兩者都包含在下面的代碼中。 我認為語法是正確的。 （但可能不是）

類/控件聲明和初始化。 （為清晰起見，刪除了許多其他代碼。如果需要，可以使用完整代碼，我將進行編輯。只是想保持簡短。）

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

@IBOutlet weak var pickerGearCategory: UIPickerView!

override func viewDidLoad() {

        super.viewDidLoad()

        pickerGearCategory.dataSource = self
        pickerGearCategory.delegate = self

    }

委托和數據源

  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

這里有numberOfComponents，但是pickerView在哪里？

Answer 2

您實現的一種協議方法是錯誤的，該方法應為：

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

您已經實現了該方法，

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

改正它，您應該就很好了。

Answer 3

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