我试图改变观察对象的值。该值将更改但不会永久更改。当我向下滚动并回滚时,该值将变回原始值。我猜是列表单元格视图中@State的问题。但我无法弄清楚在观察对象中永久更改数据的解决方案。那么我应该怎么做才能通过使用数据单元来永久更改数据。
struct ContentView: View {
@ObservedObject var dataClass = DataClass()
var body: some View {
List(dataClass.data){ item in
DataCell(item: item)
}
}
}
struct DataCell: View {
@State var item : DataModal
var body: some View{
HStack{
Text("\(item.num!)")
Text("\(item.val!)").onTapGesture {
item.val = 1
}
}
.padding(.vertical, 100)
}
}
struct DataModal : Identifiable {
var id = UUID()
var num : Int?
var val : Int?
}
class DataClass : ObservableObject {
@Published var data = [DataModal]()
init(){
load()
}
func load(){
data = [DataModal(num: 1, val: 1),DataModal(num: 2, val: 2),DataModal(num: 3, val: 3),DataModal(num: 4, val: 4),DataModal(num: 5, val: 5),DataModal(num: 6, val: 6),DataModal(num: 7, val: 7),DataModal(num: 8, val: 8),DataModal(num: 9, val: 9),DataModal(num: 10, val: 10),DataModal(num: 11, val: 11),DataModal(num: 12, val: 12),DataModal(num: 13, val: 13)]
}
}
答案 0 :(得分:1)
您传递了 DataModal 的副本,因为它是一种值类型。在这种情况下,您需要将绑定传递给 dataClass
内的原始值,例如
struct ContentView: View {
@ObservedObject var dataClass = DataClass()
var body: some View {
List(dataClass.data.indices, id: \.self){ index in
DataCell(item: $dataClass.data[index])
}
}
}
struct DataCell: View {
@Binding var item : DataModal
var body: some View{
HStack{
Text("\(item.num!)")
Text("\(item.val!)").onTapGesture {
item.val = 1
}
}
.padding(.vertical, 100)
}
}