如何解决Swift UI MacOS @已发布nil或Int
我有以下变量,我希望它以nil作为初始值,然后是Int值。
@Published var status: Int = 0
为了更好地理解,请放置所有参考代码:
struct ServerMessage: Decodable {
let token: String
}
class Http: ObservableObject {
@Published var status: Int = 0
@Published var authenticated = false
func req(url: String,httpMethod: String,body: [String: String]?) {
guard let url = URL(string: url) else { return }
let httpBody = try! JSONSerialization.data(withJSONObject: body ?? [])
var request = URLRequest(url: url)
request.httpMethod = httpMethod
request.httpBody = httpBody
request.setValue("application/json",forHTTPHeaderField: "Content-Type")
URLSession.shared.dataTask(with: request) { data,response,error in
if error != nil {
print("Error: \(String(describing: error))")
return
}
if let httpResponse = response as? HTTPURLResponse {
switch httpResponse.statusCode {
case 400: do {
print("Error: 400")
DispatchQueue.main.async {
self.status = 400
}
return
}
case 401: do {
print("Error: 401")
DispatchQueue.main.async {
self.status = 401
}
return
}
default: do {}
}
}
do {
if let data = data {
let results = try JSONDecoder().decode(ServerMessage.self,from: data)
DispatchQueue.main.async {
self.authenticated = true
}
print("Ok.",results)
} else {
print("No data.")
}
} catch {
print("Error:",error)
}
}.resume()
}
}
使用:
self.http.req(
url: "",httpMethod: "POST",body: ["email": "","password": ""]
)
解决方法
将其设为可选(以下所有更正代替了用法)
@Published var status: Int? = nil // << I like explicit initialising
更新:View中用法的可能变体
Text("\(http.status ?? 0)") // << it is Int,so ?? "" is not valid
但可能更合适(由于没有任何意义显示未知状态字段)
if http.status != nil {
Text("\(http.status!)")
}
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