无法在一个viewcontroller中使用两个UIPickerView

Question

我目前有一个包含3个文本字段的视图控制器：

customerTextField

manufacturerTextField

modelTextField

选择manufacturerTextField时，我需要出现与https://www.example.com/example/Manufacturer.php关联的UIPicker。

这个UIPicker设计有两列使用JSON数据填充。在进行选择时，UIPicker会填充manufacturerTextField和modelTextField

当用户选择customerTextField时，我希望UIPickerView显示来自https://www.example.com/example/customer.php的数据

这应该只是一个列选择。

更新后的问题：

以下是我目前所拥有的，出于某种原因，在选择customerTextField时，带有两列的UIPicker会出现manufacturerTextField数据。

    import UIKit

class CreateRMA_ViewController: UIViewController, UIPickerViewDataSource, UIPickerViewDelegate, UITextFieldDelegate {



        @IBOutlet weak var customerTextField: UITextField!
        @IBOutlet weak var manufacturerTextField: UITextField!
        @IBOutlet weak var modelTextField: UITextField!

        var selectedTextField = UITextField()

    struct Category {
        var name: String
        var items: [String]
    }
    var allCategories = [Category]()
    var selectedCategory:Category?
    var selectedItem: String?

    var pickerView: UIPickerView!
    var values: [AnyObject] = []

func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool {
    selectedTextField = textField
    pickerView.isHidden = false
    return true
}

    func numberOfComponents(in pickerView: UIPickerView) -> Int {
        if selectedTextField == customerTextField {
            return 1
        } else if selectedTextField == manufacturerTextField {
            return selectedCategory == nil ? 1 : 2
        } else {//modelTextField
            return 2
        }
    }

    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        if selectedTextField == customerTextField {
            return values.count
        } else if selectedTextField == manufacturerTextField {
            return component == 0 ? allCategories.count : selectedCategory?.items.count ?? 0
        } else {//modelTextField
            return selectedCategory?.items.count ?? 0
        }
    }

    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
        if selectedTextField == customerTextField {
            return values[row] as? String
        } else if selectedTextField == manufacturerTextField {
            if component == 0 {
                return allCategories[row].name
            } else {
                return selectedCategory?.items[row]
            }
        } else {//modelTextField
            return selectedCategory?.items[row]
        }
    }


    func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {

        if component == 0 {
            selectedCategory = allCategories[row]
            manufacturerTextField.text = allCategories[row].name
            pickerView.reloadAllComponents()
        } else {
            selectedItem = selectedCategory?.items[row]
            modelTextField.text = selectedCategory?.items[row]
        }
    }







    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()

    }


        override func viewDidLoad() {
            super.viewDidLoad()

            pickerView = UIPickerView()
            pickerView.dataSource = self
            pickerView.delegate = self
            manufacturerTextField.inputView = pickerView






            //get the values from sql/Json
            let url = NSURL(string: "https://www.example.com/test/service.php")

            let data = NSData(contentsOf: url! as URL)
            var tmpValues = try! JSONSerialization.jsonObject(with: data! as Data, options: JSONSerialization.ReadingOptions.mutableContainers) as! NSArray
            tmpValues = tmpValues.reversed() as NSArray
            reloadInputViews()


            for candidate in tmpValues {
                if let cdict = candidate as? NSDictionary {

                    //fullName is the column name in sql/json
                    let names = cdict["customer"]
                    self.values.append(names! as AnyObject)


                }
            }

            if let url = URL(string: "https://www.example.com/test/Make_Model.php"),
                let data = try? Data(contentsOf: url),
                let tmpValues = try? JSONSerialization.jsonObject(with: data, options: .mutableContainers) as? [[String:String]] {
                let tempCategories = tmpValues?.reduce(into: [String:[String]](), { (dict, value) in
                    if let manufacturer = value["manufacturer"], let model = value["model"] {
                        dict[manufacturer, default:[]].append(model)
                    }
                })
                for category in (tempCategories ?? [:]) {
                    allCategories.append(Category(name: category.key, items: category.value))
                }
                pickerView.reloadAllComponents()
            }
    }



}

Answer 1

当您有多个文本字段具有与输入视图相同的选择器视图时，您需要保留对当前所选文本字段的引用

@IBOutlet weak var customerTextField: UITextField!
@IBOutlet weak var manufacturerTextField: UITextField!
@IBOutlet weak var modelTextField: UITextField!
var selectedTextField = UITextField()

将所选文本字段分配给textFieldShouldBeginEditing中的此临时文本字段

func textFieldShouldBeginEditing(_ textField: UITextField) -> Bool {
    selectedTextField = textField
    pickerView.reloadAllComponents()
    pickerView.isHidden = false
    return true
}

并检查在选择器视图数据源中选择了哪个文本字段并委派方法并使用适当的数据源。

func numberOfComponents(in pickerView: UIPickerView) -> Int {
    if selectedTextField == customerTextField {
        return 1
    } else if selectedTextField == manufacturerTextField {
        return selectedCategory == nil ? 1 : 2
    } else {//modelTextField
        return 2
    }
}

func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    if selectedTextField == customerTextField {
        return values.count
    } else if selectedTextField == manufacturerTextField {
        return component == 0 ? allCategories.count : selectedCategory?.items.count ?? 0
    } else {//modelTextField
        return selectedCategory?.items.count ?? 0
    }
}

func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
    if selectedTextField == customerTextField {
        return values[row] as? String
    } else if selectedTextField == manufacturerTextField {
        if component == 0 {
            return allCategories[row].name
        } else {
            return selectedCategory?.items[row]
        }
    } else {//modelTextField
        return selectedCategory?.items[row]
    }
}

func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
    if selectedTextField == customerTextField {
        customerTextField.text = values[row] as? String
    } else if selectedTextField == manufacturerTextField {
        if component == 0 {
            selectedCategory = allCategories[row]
            manufacturerTextField.text = allCategories[row].name
            pickerView.reloadAllComponents()
        } else {
            selectedItem = selectedCategory?.items[row]
            modelTextField.text = selectedCategory?.items[row]
        }
    } else {//modelTextField
        modelTextField.text = selectedCategory?.items[row]
    }
}