求助 Alamofire 的 publisher 用法

在学习 macOS 开发想捣鼓个小东西自己用，零基础。这两天研究了研究 Publisher ，感觉也算是大概懂了，但是在用 Alamofire 的 publisher 的时候，怎么也搞不定了。比如如下这个只有一个函数的 APP ，为什么请求不成功呢：

 import SwiftUI import Alamofire struct ContentView: View { var body: some View { Text("Hello, world!") .padding() .onAppear(perform: load) } struct TestResponse: Decodable { let userId: Int let id: Int let title: String let body: String } func load(){ AF.request("https://jsonplaceholder.typicode.com/posts", method: .get, parameters: nil) .validate() .publishDecodable(type: [TestResponse].self) .print() .sink { print($0) } } } struct ContentView_Previews: PreviewProvider { static var previews: some View { ContentView() } } 

打印出来的是：

receive subscription: (Alamofire.DataResponsePublisher<Swift.Array<Test.ContentView.TestResponse>>.(unknown context at $1080f8314).Inner<Combine.Publishers.Print<Alamofire.DataResponsePublisher<Swift.Array<Test.ContentView.TestResponse>>>.(unknown context at $7ff81332d748).Inner<Combine.Subscribers.Sink<Alamofire.DataResponse<Swift.Array<Test.ContentView.TestResponse>, Alamofire.AFError>, Swift.Never>>>) request unlimited receive cancel receive value: (failure(Alamofire.AFError.explicitlyCancelled)) receive finished 

为什么会出现 explicitlyCancelled 呢，谢谢大家。