SwiftUI视图模型更新
我有一个有许多按钮的视图,如果用户点击按钮,Viewmodel需要用增加的值更新当前按钮SwiftUI视图模型更新,swiftui,Swiftui,我有一个有许多按钮的视图,如果用户点击按钮,Viewmodel需要用增加的值更新当前按钮 class ProductVM: ObservableObject { @Published var product : Product init(product: Product) { self.product = product } public func increaseAmount() { var myInt = Int(sel
class ProductVM: ObservableObject {
@Published var product : Product
init(product: Product) {
self.product = product
}
public func increaseAmount() {
var myInt = Int(self.product.amount) ?? 0
myInt += 1
self.product.amount = String(myInt)
print(myInt)
print("...")
}
}
问题是myInt每次仅为1,并且该值无法更新
如何更新该值并将其保存在当前模型中,以便视图知道其增加值
struct singleButtonView: View {
@ObservedObject var productVM : ProductVM
func updatePos(){
self.productVM.increaseAmount()
}
}
我称之为
singleButtonView(productVM: ProductVM(product: product))
嵌套的ObserveObject需要手动更新。下面是这样一个示例:
class Product: ObservableObject, Identifiable, Codable {
let id: Int
let name: String
let prize: Double
@Published var amount: Int = 0
enum CodingKeys: String, CodingKey {
case id
case name
case prize
case amount
}
init() {
self.id = 0
self.name = "name"
self.prize = 0
}
init(id: Int, name: String, prize: Double) {
self.id = id
self.name = name
self.prize = prize
}
required init(from decoder: Decoder) throws {
let values = try decoder.container(keyedBy: CodingKeys.self)
id = try values.decode(Int.self, forKey: .id)
name = try values.decode(String.self, forKey: .name)
prize = try values.decode(Double.self, forKey: .prize)
amount = try values.decode(Int.self, forKey: .amount)
}
func encode(to encoder: Encoder) throws {
var container = encoder.container(keyedBy: CodingKeys.self)
try container.encode(id, forKey: .id)
try container.encode(name, forKey: .name)
try container.encode(prize, forKey: .prize)
try container.encode(amount, forKey: .amount)
}
}
class ProductVM: ObservableObject {
@Published var product: Product
var cancelable: AnyCancellable? = nil
init(product: Product) {
self.product = product
self.cancelable = product.objectWillChange.sink(receiveValue: {
self.objectWillChange.send()
})
}
public func increaseAmount() {
self.product.amount += 1
}
}
struct ContentView: View {
@ObservedObject var productVM = ProductVM(product: Product())
var body: some View {
VStack {
Button(action: {
self.productVM.increaseAmount()
}) {
Text("Add")
}
Text("\(self.productVM.product.amount)")
}
}
}
我希望这有帮助!
myInt的原因是什么?直接更新product.amount即可。正确地这样做,一切都会顺利进行。我把值改成了整数,直接更新了,什么也没发生。其他代码可以吗?或者您看到了什么问题吗?如何用我的产品结构的值填充产品类?哪些值?您可以将@Published变量绑定到UI,例如我向您展示的TextField。。。将产品strict更改为类,从ObserveObject继承并添加@Published属性包装器。。。然后把我所有的都加进去ProductVM@xyzcodeeee我在产品类别中添加了您要求的内容,但我还有其他问题。但这个问题现在已经解决了。