【发布时间】：2020-01-13 20:00:40
【问题描述】：
我从我的 api 获取数据并为它们创建一个类。我可以使用 swifyJSON 正确初始化它们。问题是当我将observedObject 放入List 时，它只能正确显示一次。我改变视图后它会崩溃。它非常强大，因为我的其他具有类似数据结构的列表可以工作。（此视图位于 tabView 中）有人知道我的 getAllNotification() 应该将 view.onAppear() 或 List.onAppear() 放在哪里吗？谢谢！！
class ManagerNotification : Identifiable, ObservableObject{
@Published var id = UUID()
var notifyId : Int = 0
var requestId : Int = 0
var requestName: String = ""
var groupName : String = ""
// var imageName: String { return name }
init(jsonData:JSON) {
notifyId = jsonData["notifyId"].intValue
requestId = jsonData["requestId"].intValue
requestName = jsonData["requestName"].stringValue
groupName = jsonData["groupName"].stringValue
}
}
import SwiftUI
import SwiftyJSON
struct NotificationView: View {
var roles = ["userNotification", "managerNotification"]
@EnvironmentObject var userToken:UserToken
@State var show = false
@State private var selectedIndex = 0
@State var userNotifications : [UserNotification] = [UserNotification]()
@State var managerNotifications : [ManagerNotification] = [ManagerNotification]()
var body: some View {
VStack {
Picker(selection: $selectedIndex, label: Text(" ")) {
ForEach(0..<roles.count) { (index) in
Text(self.roles[index])
}
}
.pickerStyle(SegmentedPickerStyle())
containedView()
Spacer()
}
.onAppear(perform: getAllNotification)
}
func containedView() -> AnyView {
switch selectedIndex {
case 0:
return AnyView(
List(userNotifications) { userNotification in
UserNotificationCellView(userNotification: userNotification)
}
)
case 1:
return AnyView(
List(managerNotifications) { managernotification in
ManagerNotificationCellView(managerNotification : managernotification)
}
.onAppear(perform: getManagerNotification)
)
default:
return AnyView(Text("22").padding(40))
}
}
func getAllNotification(){
// if (self.userNotifications.count != 0){
// self.userNotifications.removeAll()
// }
// I think the crash was in here, because when i don't use removeAll().
// It works fine, but i don't want every times i change to this view. my array will be longer and
// longer
if (self.managerNotifications.count != 0){
self.managerNotifications.removeAll()
}
NetWorkController.sharedInstance.connectApiByPost(api: "/User/email", params: ["token": "\(self.userToken.token)"])
{(jsonData) in
if let result = jsonData["msg"].string{
print("eeee: \(result)")
if(result == "you dont have any email"){
}else if(result == "success get email"){
if let searchResults = jsonData["mail"].array {
for notification in searchResults {
self.userNotifications.append(UserNotification(jsonData: notification))
}
}
}
}
}
NetWorkController.sharedInstance.connectApiByPost(api: "/Manager/email", params: ["token": "\(self.userToken.token)"])
{(jsonData) in
if let result = jsonData["msg"].string{
print("eeee: \(result)")
if(result == "you dont have any email"){
}else if(result == "success get email"){
if let searchResults = jsonData["mail"].array {
for notification in searchResults {
self.managerNotifications.append(ManagerNotification(jsonData: notification))
}
}
}
}
}
}
func getManagerNotification(){
// if (self.managerNotifications.count != 0){
// self.managerNotifications.removeAll()
// }
print(self.managerNotifications.count)
NetWorkController.sharedInstance.connectApiByPost(api: "/Manager/email", params: ["token": "\(self.userToken.token)"])
{(jsonData) in
if let result = jsonData["msg"].string{
print("eeee: \(result)")
if(result == "you dont have any email"){
}else if(result == "success get email"){
if let searchResults = jsonData["mail"].array {
for notification in searchResults {
self.managerNotifications.append(ManagerNotification(jsonData: notification))
}
}
}
}
}
}
}
错误信息
仅警告一次：UITableView 被告知要在视图层次结构中布局其可见单元格和其他内容（表格视图或其超级视图之一尚未添加到窗口中）。这可能会在没有准确信息的情况下强制表视图内的视图加载和执行布局（例如，表视图边界、特征集合、布局边距、安全区域插入等），从而导致错误，并且还会由于额外的布局传递而导致不必要的性能开销.在 UITableViewAlertForLayoutOutsideViewHierarchy 处创建一个符号断点，以便在调试器中捕获此问题并查看导致此问题发生的原因，因此如果可能，您可以完全避免此操作，或者将其推迟到表格视图添加到窗口中。原因：'尝试删除第0节，但更新前只有0节'
【问题讨论】：
标签： swiftui swiftui-list