【发布时间】：2022-02-27 07:19:08
【问题描述】：
我正在尝试使用 SwiftUI 制作一个小型社交媒体应用程序。 我创建了一个名为 user 的 ObservableObject 类和一个 Sign up 视图，其中 var 获得了价值。当我想在我的 ProfilView 中显示数据时，会发生错误。
线程 1：致命错误：未找到用户类型的 ObservableObject。 User 的 View.environmentObject(_:) 作为该视图的祖先可能会丢失。
主页是主视图，当按下按钮时，我会在视图之间切换，这是 AppInformation 中的布尔变化。
struct ProfileView: View {
@EnvironmentObject var appUser: User
@State var beschreibung: String = ""
@State var benutzername: String = ""
@State var name: String = ""
var body: some View {
init() {
benutzername = appUser.username
name = appUser.name
}
ZStack {
Rectangle()
.frame(width: 400, height: 720)
.cornerRadius(50)
.foregroundColor(.gray)
.overlay(
HStack {
Image(systemName: "person.circle")
.resizable()
.frame(width: 100, height: 100)
.onTapGesture {
print("pressed")
}
.padding(20)
.overlay(
ZStack{
Rectangle()
.frame(width: 20, height: 20)
.offset(x: 35, y: -35)
.foregroundColor(.white)
Image(systemName: "plus.circle.fill")
.resizable()
.frame(width: 30, height: 30)
.offset(x: 35, y: -35)
.foregroundColor(.blue)
}
)
VStack {
Text(benutzername)
.font(.largeTitle)
.frame(width: 240 ,alignment: .leading)
.offset(x: -10, y: -25)
.lineLimit(1)
Text(name)
.frame(width: 220, alignment: .leading)
.offset(x: -15,y: -20)
.lineLimit(1)
}
}
.frame(width: 400, height: 720, alignment: .topLeading)
)
.padding()
ZStack {
Rectangle()
.foregroundColor(.secondary)
.frame(width: 380, height: 510)
.cornerRadius(45)
}
.frame(width: 400, height: 700, alignment: .bottom)
.padding()
}
.frame(maxWidth: .infinity, maxHeight: .infinity, alignment: .top)
}
}
class User: ObservableObject{
@Published var username: String = ""
@Published var name: String = ""
var password: String = ""
@Published var email: String = ""
@Published var beschreibung: String = ""
}
@State var isSecured: Bool = true
@State var noPassword: Int = 0
@State var noEmail: Int = 0
@State var noUsername: Int = 0
@State var noName: Int = 0
@State var password: String = ""
@State var username: String = ""
@State var name: String = ""
@State var email: String = ""
@EnvironmentObject var appInfo: AppInformation
@EnvironmentObject var appUser: User
var body: some View {
ZStack {
RoundedRectangle(cornerRadius: 25)
.frame(width: 380, height: 650)
.overlay(Text("Erstelle Accout ")
.foregroundColor(.white)
.frame(width: 360, height: 510, alignment: .top)
.font(.headline))
ZStack {
VStack {
TextField("Username", text: $username)
.frame(width:180 ,height:40 ,alignment: .center)
.multilineTextAlignment(.center)
.font(.headline)
.background(Color.gray.opacity(0.25))
.clipShape(Capsule())
.foregroundColor(.white)
.border(.red, width: CGFloat(noUsername))
Spacer()
.frame(height: 35)
TextField("Full name", text: $name)
.frame(width:180 ,height:40 ,alignment: .center)
.multilineTextAlignment(.center)
.font(.headline)
.background(Color.gray.opacity(0.25))
.clipShape(Capsule())
.foregroundColor(.white)
.border(.red, width: CGFloat(noName))
Spacer()
.frame(height: 35)
TextField("Email", text: $email)
.frame(width:180 ,height:40 ,alignment: .center)
.multilineTextAlignment(.center)
.font(.headline)
.background(Color.gray.opacity(0.25))
.clipShape(Capsule())
.foregroundColor(.white)
.border(.red, width: CGFloat(noEmail))
Spacer()
.frame(height: 35)
HStack {
Spacer()
.frame(width: 37)
if isSecured {
SecureField("Password", text: $password)
.frame(width:180 ,height:40 ,alignment: .center)
.multilineTextAlignment(.center)
.font(.headline)
.background(Color.gray.opacity(0.25))
.clipShape(Capsule())
.foregroundColor(.white)
.border(.red, width: CGFloat(noPassword))
} else {
TextField("Password", text: $password)
.frame(width:180 ,height:40 ,alignment: .center)
.multilineTextAlignment(.center)
.font(.headline)
.background(Color.gray.opacity(0.25))
.clipShape(Capsule())
.foregroundColor(.white)
.border(.red, width: CGFloat(noPassword))
}
ZStack {
Button(" ") {
isSecured.toggle()
print(isSecured)
}
Image(systemName: self.isSecured ? "eye" : "eye.slash")
.foregroundColor(.gray)
}
}
Spacer()
.frame(height: 60)
Button("Erstellen"){
if username == "" {
noUsername = 1
if name == "" {
noName = 1
if email == "" {
noEmail = 1
if password == "" {
noPassword = 1
}
}
else if password == "" {
noPassword = 1
}
}
else if email == "" {
noEmail = 1
if password == "" {
noPassword = 1
}
}
else if password == "" {
noPassword = 1
}
}
else if name == "" {
noName = 1
if email == "" {
noEmail = 1
if password == "" {
noPassword = 1
}
}
else if password == "" {
noPassword = 1
}
}
else if email == "" {
noEmail = 1
if password == "" {
noPassword = 1
}
}
else if password == "" {
noPassword = 1
}
else {
appUser.username = username
appUser.email = email
appUser.password = password
appUser.name = name
appInfo.finished = true
}
}
.font(.headline)
.frame(width: 150, height: 50)
.background(.blue)
.foregroundColor(.white)
.clipShape(Capsule())
}
}
}
} }
class AppInformation: ObservableObject{
@Published var home: Bool = true
@Published var camera: Bool = false
@Published var friends: Bool = false
@Published var profil: Bool = false
@Published var showBar: Bool = true
@Published var finished: Bool = false
}
struct Home: View {
@EnvironmentObject var appInfo: AppInformation
@EnvironmentObject var appUser: User
var body: some View {
ZStack {
if appInfo.finished {
if appInfo.home {
HomeView()
}
else if appInfo.camera {
MakePostView()
}
else if appInfo.friends {
FriendsView()
}
else if appInfo.profil {
ProfileView()
.environmentObject(appUser)
}
if appInfo.showBar {
NavigationBar()
}
}
else {
ErstellenView().environmentObject(appInfo)
.environmentObject(appUser)
}
}
}
}
【问题讨论】：
-
错误告诉你没有传递
Home中的@EnvironmentObject var appUser: User所需的User对象。因此，在Home视图之前的层次结构中的某处，您应该创建了一个@StateObject var appUser = User()，并使用.environmentObject(appUser)将其传递给Home。或者，在Home中将@EnvironmentObject var appUser: User替换为@StateObject var appUser = User()。请注意，同样在ProfileView中，视图主体内不能有init()，请将其放在外面。 -
嗨，我已经做到了
-
workingdog 是对的，你在某处错过了它。
-
错误是因为EnvironmentObjects，即使正确地注入到视图层次结构中，在初始化时也不一定可用。因此，要么将依赖项直接传递给你的 init，要么在其他地方进行设置（如 onAppear）