Img: Now the app: data does not change
Img: Now the app: data does not change
我目前正在使用Swift开发一个应用程序，我使用UIPickerView和TableView（这适用于单一视图）。我想更改pickerView（myPickerView）中的键，将TableView（myTableView）中的值更改为正确的数据（自动）。
import UIKit
struct Cars {
var carName: String!
var carModel: [String]!
}
class ViewController: UIViewController, UIPickerViewDataSource, UIPickerViewDelegate, UITableViewDataSource, UITableViewDelegate {
// Dictionary
var myDictionary = [
"BMW": ["M3", "M4", "M5"],
"Porsche": ["Panamera", "911", "Cayenne"],
"Audi": ["RS4", "RS6", "RS5"],
"Mercedes": ["Class S", "SL", "AMG GTR"]
]
// Array
var allObjects = [Cars]()
override func viewDidLoad() {
super.viewDidLoad()
view.backgroundColor = .white
// Func - Constraint PickerView/TableView/Button
setupUI()
// PickerView Delegate/DataSource
myPickerView.dataSource = self
myPickerView.delegate = self
// TableView Delegate/DataSource
myTableView.delegate = self
myTableView.dataSource = self
myTableView.register(UITableViewCell.self, forCellReuseIdentifier: "cellId")
// Loop key and value - myDictionary
for (key, value) in myDictionary {
allObjects.append(Cars(carName: key, carModel: value))
}
}
// My TableView
let myTableView: UITableView = {
let tv = UITableView()
tv.translatesAutoresizingMaskIntoConstraints = false
return tv
}()
// My PickerView
let myPickerView: UIPickerView = {
let bp = UIPickerView()
bp.translatesAutoresizingMaskIntoConstraints = false
return bp
}()
// Button Open myPickerView and setup nameCar
var myChoiceCarNameButton: UIButton = {
let button = UIButton(type: .system)
button.setTitle("Choice Car", for: .normal)
button.tintColor = .black
button.addTarget(self, action: #selector(handleChoiceCarName), for: .touchUpInside)
button.translatesAutoresizingMaskIntoConstraints = false
return button
}()
// Target selector button "myChoiceCarNameButton"
@objc func handleChoiceCarName() {
print("Tapped choice car name ")
view.layoutIfNeeded()
UIView.animate(withDuration: 0.25, animations: {
self.view.layoutIfNeeded()
}) { (completed) in
UIView.animate(withDuration: 0.25, animations: {
self.myPickerView.alpha = 1
self.view.layoutIfNeeded()
})
}
}
// Constraint button/pickerView/TableView
private func setupUI() {
view.addSubview(myChoiceCarNameButton)
myChoiceCarNameButton.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 20).isActive = true
myChoiceCarNameButton.centerXAnchor.constraint(equalTo: view.centerXAnchor).isActive = true
myChoiceCarNameButton.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
myChoiceCarNameButton.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
view.addSubview(myPickerView)
myPickerView.alpha = 0
myPickerView.topAnchor.constraint(equalTo: myChoiceCarNameButton.bottomAnchor).isActive = true
myPickerView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
myPickerView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
view.addSubview(myTableView)
myTableView.topAnchor.constraint(equalTo: myPickerView.bottomAnchor, constant: 10).isActive = true
myTableView.leftAnchor.constraint(equalTo: view.leftAnchor).isActive = true
myTableView.rightAnchor.constraint(equalTo: view.rightAnchor).isActive = true
myTableView.bottomAnchor.constraint(equalTo: view.bottomAnchor, constant: 10).isActive = true
}
// MARK: - PickerViewDelegate/DataSource Methods
func numberOfComponents(in pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
if component == 0 {
return allObjects.count
} else {
let selectedBody = pickerView.selectedRow(inComponent: 0)
return allObjects[selectedBody].carName.count
}
}
func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
if component == 0 {
return allObjects[row].carName
} else {
let selectedCar = pickerView.selectedRow(inComponent: 0)
return allObjects[selectedCar].carName
}
}
func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
// Set the button title
myChoiceCarNameButton.setTitle(allObjects[row].carName, for: .normal)
view.layoutIfNeeded()
UIView.animate(withDuration: 0.25, animations: {
self.myPickerView.alpha = 0
self.view.layoutIfNeeded()
}) { (completed) in
UIView.animate(withDuration: 0.25, animations: {
self.view.layoutIfNeeded()
self.myTableView.reloadData()
})
}
} // End did select
// MARK: - TableViewDelegate/DataSource Methods
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return allObjects[section].carModel.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "cellId", for: indexPath)
cell.backgroundColor = .green
cell.textLabel?.font = UIFont.boldSystemFont(ofSize: 16)
cell.textLabel?.text = allObjects[indexPath.section].carModel[indexPath.row]
return cell
}
} // End class
也许有人发现了类似的情况并知道该怎么做？ 也许某人更容易解决如何实现这种效果？
答案 0 :(得分：0)
问题在于：
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return allObjects[section].carModel.count
}
当用户在func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int)功能中做出选择时，您必须将选定的汽车保存在变量中。然后在numberOfRowsInSection函数中，您必须使用此变量：
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return allObjects[selectedCarIndex].carModel.count
}
另外，您没有指定func numberOfSections(in tableView: UITableView) -> Int委托方法，因此我假设默认值始终为1，因此UITableView中只有1个部分。因此，在func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int委托方法中，该部分始终为1，因此这就是您在UITableView中看不到任何更改的原因。