将从完成处理程序接收的值快速传递到textview

Question

我是Swift的新手，正在尝试向本地主机发出http请求。像异步，关闭之类的快速处理httprequest的内容太多了，这使我感到困惑。我已经实现了urlSession，并且可以在takeRequest中打印从completionhandler接收到的数据。我正在尝试从takeRequest函数返回值并将其传递给PopUpTextView。我该怎么办？

PareseRequest.swift 

func StartRequest(urlRequest: URLRequest,
                  completionHandler:@escaping ([[String:Any]], Error?) -> Void){
    let task = URLSession.shared.dataTask(with: urlRequest) { (data, response, error) in

    // Check if Error took place
    if let error = error {
        print("Error took place \(error)")
        return
    }

    // Read HTTP Response Status code
    if let response = response as? HTTPURLResponse {
        print("Response HTTP Status code: \(response.statusCode)")
    }

    // Convert HTTP Response Data to a simple String
    if let data = data, let dataString = String(data: data, encoding: .utf8) {
        //completionHandler(dataString, nil)
        //print("Response data string:\n \(dataString)")
        do{
            if let json = try JSONSerialization.jsonObject(with: data, options: []) as? [String:Any]{
                print("imhere")
                if let names = json["list"] as? [[String:Any]] {
                // print("json names")
                // print(names)
                completionHandler(names, nil)
                }
                else{
                    print("json did not load")
                    }
                   }
               }catch let error as NSError{
                   print("Failed to load: \(error.localizedDescription)")
               }
    }
}
task.resume()
}

func takeReqeust(completionHandler:@escaping ([[String:Any]], Error?) -> Void) -> Void{
    let url = URL(string:  "http://localhost:3000")
    var request = URLRequest(url: url!)
    request.httpMethod = "GET"

    var new_data: String  = ("")
    StartRequest(urlRequest: request) { (data, error)  in
        print("I'm here")
        completionHandler(data,nil)
        new_data = data[0].description
        print(new_data)
    }

}

PopUpTextView.Swift

struct PopUpTextView: View {
    var body: some View {
        Text()
    }

Answer 1

这是您的代码快照的最简单的演示解决方案

struct PopUpTextView: View {
    @State private var data = "Loading..."
    var body: some View {
        Text(data)
         .onAppear {
            takeReqeust { (data, error) in   // original typo? - takeRequest?
                if let first = data.first {
                   self.data = first
                } else {
                   self.data = "No data"
                }
            }
         }
    }
}