在我的多维列表中,当我尝试删除行时遇到问题 - 线程 1:致命错误:索引超出范围:
struct Parent: Identifiable {
let id = UUID()
let name: String
var children: [Child]?
}
struct Child: Identifiable {
let id = UUID()
let name: String
}
class AppState: ObservableObject {
@Published var parents: [Parent]
init() {
self.parents = [
Parent(name: "Foo", children: [Child(name: "bar")]),
Parent(name: "FooBar", children: nil)
]
}
}
struct ContentView: View {
@EnvironmentObject var appState: AppState
var body: some View {
NavigationView {
List {
ForEach (0..<appState.parents.count) { parentIndex in
NavigationLink (destination: ChildrenView(parentIndex: parentIndex).environmentObject(self.appState)) {
Text(self.appState.parents[parentIndex].name) // Thread 1: Fatal error: Index out of range
}
}
.onDelete(perform: deleteItem)
}
}
}
private func deleteItem(at indexSet: IndexSet) {
self.appState.parents.remove(atOffsets: indexSet)
}
}
struct ChildrenView: View {
@EnvironmentObject var appState: AppState
var parentIndex: Int
var body: some View {
List {
ForEach (0..<(appState.parents[parentIndex].children?.count ?? 0)) { childIndex in
Text(self.appState.parents[self.parentIndex].children![childIndex].name)
}
}
}
}
我重建了这种情况,因为我在一个具有更多代码的更大项目中遇到了这个问题。尤其是当我尝试删除有孩子的父母时,我在儿童视图中遇到了问题。对于没有孩子的父母,我可以删除它们。在这段代码中,我根本无法删除一行。
我认为这个问题在某种程度上与parentIndex
视图通过可观察对象更改重新加载时没有减少有关。