在 SwiftUI 中的簡單 URLSession POST 請求期間添加 ProgressView

Question

我想在一個簡單的 URL POST 請求過程中顯示進度視圖。 我想做的是將按鈕變成ProgressView微調器（通常是默認設置），因為它正在通過requestTest function 進程。 請求完成后，進度視圖消失並變回按鈕。

這是代碼。

struct ContentView: View {
    @State private var tweetID = ""
    @State private var tweetStatus = ""
    @State private var response = ""
    @State var showAlert = false
    @State var sendToWebhook = false
    
    var body: some View {
        NavigationView {
            Form {
                Section(footer: Text("Test")) {
                    TextField("Field to place response data", text: $response)
                    TextEditor( text: $tweetStatus)
                        .frame(height: 100)
                }
                Section {
                    
                    Button("Get Data") {

                    // Where progress should start before function 
                        ProgressView("Test", value: 100, total: 100)
                        requestTest() { results in
                            response = results
                            if response == "No Data!" {
                                showAlert = true
                            }
                        }
                    }
                    if self.requestTest {
                        ProgressView()
                    } 
                }
            }
            .alert(isPresented: $showAlert) {
                Alert(title: Text("Tweet Sent"), message: Text("Your Tweet is sent! Your Tweet ID is shown in the field"), dismissButton: .default(Text("OK")))
            }
        }
    }
    func requestTest(completion: @escaping(String) -> ()) {   
        if let url = URL(string: "https://requestbin.net/r/ag4ipg7n") {
            
            var request = URLRequest(url: url)
            request.httpMethod = "POST"
            request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
            
            var components = URLComponents(url: url, resolvingAgainstBaseURL: false)!
            components.queryItems = [ URLQueryItem(name: "TweetID", value: response), 
                                      URLQueryItem(name: "Status", value: tweetStatus)]
            
            if let query = components.url!.query {
                request.httpBody = Data(query.utf8)
            }
            
            let task = URLSession.shared.dataTask(with: request) { data, response, error in
                if let data = data,
                   let apiResponse = String(data: data, encoding: .utf8) {
                    
                    // IF Completed, these actions are shown below
                    completion(apiResponse)   
                    self.showAlert = true
                    tweetStatus = "" 
                } else {
                    completion("No Data!")  
                }
            }
            task.resume()
        }
    }
}

我想如果我嘗試這樣做if self.requestTest { ProgressView() } ，但無濟於事，因為它給了我一個錯誤，上面寫着Cannot convert value of type '(@escaping (String) -> ()) -> ()' to expected condition type 'Bool' 。

有沒有辦法做到這一點？

Answer 1

有多種方法可以滿足您的要求。 這只是一種方法：

struct ContentView: View {
    @State private var tweetID = ""
    @State private var tweetStatus = ""
    @State private var response = ""
    @State var showAlert = false
    @State var sendToWebhook = false
    
    @State var inProgress = false // <--- here
    
    var body: some View {
        NavigationView {
            Form {
                Section(footer: Text("Test")) {
                    TextField("Field to place response data", text: $response)
                    TextEditor( text: $tweetStatus)
                        .frame(height: 100)
                }
                Section {
                    Button("Get Data") {
                        inProgress = true  // <--- here
                        requestTest() { results in
                            inProgress = false // <--- here
                            response = results
                            if response == "No Data!" {
                                showAlert = true
                            }
                        }
                    }
                    if inProgress {  // <--- here
                        ProgressView()
                    }
                }
            }
            .alert(isPresented: $showAlert) {
                Alert(title: Text("Tweet Sent"), message: Text("Your Tweet is sent! Your Tweet ID is shown in the field"), dismissButton: .default(Text("OK")))
            }
        }
    }