Question

冰雹

我很难编写干净的代码。因此，我想在单独的类文件和扩展中保留我的数据源和deletegate。所以想要更接近M-V-C风格。因此，我的模型与我的所有控制器类和视图类分开。但填充pickerView对象时出现问题。这是代码;

//我的代表和数据源进口基金会导入UIKit

class MyPickerView: NSObject{
var data = PickerViewData.getData()



}
extension MyPickerView: UIPickerViewDataSource{
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    return 1
}

func numberOfComponents(in pickerView: UIPickerView) -> Int {
    return self.data.count
}    
}

extension MyPickerView: UIPickerViewDelegate{
func pickerView(_ pickerView: UIPickerView, rowHeightForComponent 
component: Int) -> CGFloat {
    return 100
}

func pickerView(_ pickerView: UIPickerView, viewForRow row: Int, 
forComponent component: Int, reusing view: UIView?) -> UIView {

    let view = UIView(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
    let dayLbl = UILabel(frame: CGRect(x: 0, y: 10, width: 100, height: 15))
    let priceLbl = UILabel(frame: CGRect(x: 0, y: 0, width: 100, height: 100))
    let petLbl = UILabel(frame: CGRect(x: 0, y: 78, width: 100, height: 15))
    dayLbl.text = data[row].dayName
    priceLbl.text = String(data[row].price)
    petLbl.text = data[row].petName

    dayLbl.textAlignment = .center
    priceLbl.textAlignment = .center
    petLbl.textAlignment = .center
    view.addSubview(dayLbl)
    view.addSubview(priceLbl)
    view.addSubview(petLbl)
    return view
}

}

//我的模特

import Foundation

struct PickerViewModel{
var dayName:String!
var price:Double!
var petName:String!
init(dayName:String,price:Double,petName:String) {
    self.dayName = dayName
    self.price = price
    self.petName = petName
}

}
struct PickerViewData {
static func getData() -> [PickerViewModel]{
    let m = PickerViewModel(dayName: "Pazartesi", price: 32.3, 
petName: "Köpek")
    let p = PickerViewModel(dayName: "Salı", price: 32.3, petName: 
"Kuş")
    let z = PickerViewModel(dayName: "Çarşamba", price: 32.3, 
petName: "Kedi")
    let t = PickerViewModel(dayName: "Perşembe", price: 32.3, 
petName: "Domuz")
    let k = PickerViewModel(dayName: "Cuma", price: 32.3, petName: 
"Kanarya")
    return [m,p,z,t,k]
}
}

//我的控制器

import UIKit

class FirstVC: UIViewController {

override func viewDidLoad() {
    super.viewDidLoad()
    self.view.backgroundColor = .white
    let pickerView = UIPickerView(frame: CGRect(x: 100, y: 100, 
width: 200, height: 500))
    let deldat = MyPickerView()
    pickerView.delegate = deldat
    pickerView.dataSource = deldat
    self.view.addSubview(pickerView)
}

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

}

Answer 1

选择器视图的dataSource和delegate属性被声明为weak - 这意味着他们不会保留您的MyPickerView实例。由于您的实例是局部变量，因此只要viewDidLoad退出，它就会被释放。

您需要将MyPickerView实例保存在实例属性中，以便在视图控制器的生命周期内保留它：

import UIKit

class FirstVC: UIViewController {

    private var deldat: MyPickerView!

    override func viewDidLoad() {
        super.viewDidLoad()
        self.view.backgroundColor = .white
        let pickerView = UIPickerView(frame: CGRect(x: 100, y: 100, 
width: 200, height: 500))
        self.deldat = MyPickerView()
        pickerView.delegate = deldat
        pickerView.dataSource = deldat
        self.view.addSubview(pickerView)
    }
}

UIPickerView没有填充

1 个答案: