我有一些变量要传递给 ContentView。
这是 Data.swift 文件，其中包含获取变量的类和函数：
import SwiftUI
class Api {
func getValues() {
let url = URL(string: "URL")
guard let requestUrl = url else { fatalError() }
var request = URLRequest(url: requestUrl)
request.httpMethod = "GET"
request.setValue("User Agent", forHTTPHeaderField: "User-Agent")
request.setValue("Auth", forHTTPHeaderField: "Authorization")
URLSession.shared.dataTask(with: request) { (data, _, _) in
let dataString = String(data: data!, encoding: .utf8)
func convertToDictionary(text: String) -> [String: Any]? {
if let data = text.data(using: .utf8) {
do {
return try JSONSerialization.jsonObject(with: data, options: []) as? [String: Any]
} catch {
print(error.localizedDescription)
}
}
return nil
}
let dict = convertToDictionary(text: dataString!)
let array = dict!["array1"] as? NSArray
let array0 = array![0] as? NSDictionary
let id = array0!["id"] as! String
let objects = array0!["object"] as! NSDictionary
var total = 0
var i = 0
for object in objects {
let key = object.key as! String
let tmpDict = objects[(key)] as! NSDictionary
let tmpStr = tmpDict["raw_value"] as! String
let tmpD = Double(tmpStr)
let value = Int(tmpD!)
print(value)
total+=value
i+=1
}
print("ID: \(id)")
let fractionalProgress = CGFloat(total / i)/6
let roundedProgress = CGFloat(round(100*fractionalProgress)/100)
print("Average value: \(roundedProgress)")
}
.resume()
}
}
为了简单起见，我在下面包含了我正在使用的 JSON 的一部分：
{
"array1": [
{
"link_id": 1,
"object": {
"2000000000007522336": {
"is_draft": 0,
"value": "4",
"show_text": null,
"show_icon_mobile": null,
"raw_value": "4.00",
"numerical_value": null
},
"2000000000016619051": {
"is_draft": 0,
"value": "6",
"show_text": null,
"show_icon_mobile": null,
"raw_value": "6.00",
"numerical_value": null
}
},
"deleted_at": null,
"id": "1_20",
"status_id": 1,
"target_num": 1
},
{
"link_id": 55,
"object": {
"2000000000010046787": {
"is_draft": 0,
"value": "6",
"show_text": null,
"show_icon_mobile": null,
"raw_value": "6.00",
"numerical_value": null
},
"2000000000005323660": {
"is_draft": 0,
"value": "6",
"show_text": null,
"show_icon_mobile": null,
"raw_value": "6.00",
"numerical_value": null
},
"2000000000006311217": {
"is_draft": 0,
"value": "6",
"show_text": null,
"show_icon_mobile": null,
"raw_value": "6.00",
"numerical_value": null
},
"2000000000011929948": {
"is_draft": 0,
"value": "6",
"show_text": null,
"show_icon_mobile": null,
"raw_value": "6.00",
"numerical_value": null
},
"2000000000004856132": {
"is_draft": 0,
"value": "6",
"show_text": null,
"show_icon_mobile": null,
"raw_value": "6.00",
"numerical_value": null
},
"2000000000007455406": {
"is_draft": 0,
"value": "6",
"show_text": null,
"show_icon_mobile": null,
"raw_value": "6.00",
"numerical_value": null
},
"2000000000009846642": {
"is_draft": 0,
"value": "6",
"show_text": null,
"show_icon_mobile": null,
"raw_value": "6.00",
"numerical_value": null
},
"2000000000016910392": {
"is_draft": 0,
"value": "6",
"show_text": null,
"show_icon_mobile": null,
"raw_value": "6.00",
"numerical_value": null
},
"2000000000014735487": {
"is_draft": 0,
"value": "6",
"show_text": null,
"show_icon_mobile": null,
"raw_value": "6.00",
"numerical_value": null
}
},
"deleted_at": null,
"id": "55_20",
"status_id": 1,
"target_num": 2
},
{
"link_id": 2,
"object": {
"2000000000012123534": {
"is_draft": 0,
"value": "6",
"show_text": null,
"show_icon_mobile": null,
"raw_value": "6.00",
"numerical_value": null
},
"2000000000004686641": {
"is_draft": 0,
"value": "6",
"show_text": null,
"show_icon_mobile": null,
"raw_value": "6.00",
"numerical_value": null
},
"2000000000006918209": {
"is_draft": 0,
"value": "6",
"show_text": null,
"show_icon_mobile": null,
"raw_value": "6.00",
"numerical_value": null
},
"2000000000007310987": {
"is_draft": 0,
"value": "6",
"show_text": null,
"show_icon_mobile": null,
"raw_value": "6.00",
"numerical_value": null
},
"2000000000013890209": {
"is_draft": 0,
"value": "6",
"show_text": null,
"show_icon_mobile": null,
"raw_value": "6.00",
"numerical_value": null
}
},
"deleted_at": null,
"id": "2_20",
"status_id": 1,
"target_num": 3
}
]
}
这是内容视图：
import SwiftUI
struct ContentView: View {
@State var show = false
var body: some View {
Text("Hello, world!")
.onAppear() {
Api().getValues()
}
Text("Values should appear here.")
Circle()
.trim(from: show ? "roundedProgress CGFloat" : 0.99, to: 1)
.stroke(Color.green, style: StrokeStyle(lineWidth: 7.5, lineCap: .round, lineJoin: .round))
.rotationEffect(.degrees(90))
.rotation3DEffect(Angle(degrees: 180), axis: (x: 1, y: 0, z: 0))
.frame(width: 100, height: 100)
.animation(.easeOut)
.onAppear() {
DispatchQueue.main.asyncAfter(deadline: .now() + 0.25) {
self.show.toggle()
}
}
}
}
struct ContentView_Previews: PreviewProvider {
static var previews: some View {
ContentView()
}
}
理想情况下，我想根据 roundedProgress 浮点值修剪环形视图，并在 onAppear() 之后的文本操作中显示这些值。
我尝试将整个函数放在 onAppear() 操作中，但没有任何改变。在没有 onAppear() 的情况下放置代码会在我用于获取数据的 URLSession 操作上显示错误“无法生成表达式诊断；请提交错误报告”。