Question

据我了解，默认情况下，Alamofire请求在后台线程中运行。

当我尝试运行此代码时：

let productsEndPoint: String = "http://api.test.com/Products?username=testuser"

        Alamofire.request(productsEndPoint, method: .get)
            .responseJSON { response in
                // check for errors
                guard response.result.error == nil else {
                    // got an error in getting the data, need to handle it
                    print("Inside error guard")
                    print(response.result.error!)
                    return
                }

                // make sure we got some JSON since that's what we expect
                guard let json = response.result.value as? [String: Any] else {
                    print("didn't get products as JSON from API")
                    print("Error: \(response.result.error)")
                    return
                }

                // get and print the title
                guard let products = json["products"] as? [[String: Any]] else {
                    print("Could not get products from JSON")
                    return
                }
                print(products)

        }

在网络通话中的所有项目都已完成打印之前，用户界面没有响应;所以我尝试将GCD与Alamofire一起使用：

let queue = DispatchQueue(label: "com.test.api", qos: .background, attributes: .concurrent)

    queue.async {

        let productsEndPoint: String = "http://api.test.com/Products?username=testuser"

        Alamofire.request(productsEndPoint, method: .get)
            .responseJSON { response in
                // check for errors
                guard response.result.error == nil else {
                    // got an error in getting the data, need to handle it
                    print("Inside error guard")
                    print(response.result.error!)
                    return
                }

                // make sure we got some JSON since that's what we expect
                guard let json = response.result.value as? [String: Any] else {
                    print("didn't get products as JSON from API")
                    print("Error: \(response.result.error)")
                    return
                }

                // get and print the title
                guard let products = json["products"] as? [[String: Any]] else {
                    print("Could not get products from JSON")
                    return
                }
                print(products)

        }
    }

并且UI仍然没有像以前那样没有响应。

我在这里做错了什么，或者Alamofire的错误在哪里？

Answer 1

我错误地认为Alamofire默认运行在后台线程上。它实际上默认在主队列上运行。我已经在Alamofire的Github页面上打开了一个问题，它在这里得到了解决：https://github.com/Alamofire/Alamofire/issues/1922

解决我的问题的正确方法是使用＆＃34; 队列＆＃34;指定我希望我的请求运行的队列类型。 .responseJSON方法的参数（

.responseJSON(queue: queue) { response in
...
}

）

这是我的代码的完整更正版本：

let productsEndPoint: String = "http://api.test.com/Products?username=testuser"

    let queue = DispatchQueue(label: "com.test.api", qos: .background, attributes: .concurrent)

    Alamofire.request(productsEndPoint, method: .get)
        .responseJSON(queue: queue) { response in
            // check for errors
            guard response.result.error == nil else {
                // got an error in getting the data, need to handle it
                print("Inside error guard")
                print(response.result.error!)
                return
            }

            // make sure we got some JSON since that's what we expect
            guard let json = response.result.value as? [String: Any] else {
                print("didn't get products as JSON from API")
                print("Error: \(response.result.error)")
                return
            }

            // get and print the title
            guard let products = json["products"] as? [[String: Any]] else {
                print("Could not get products from JSON")
                return
            }
            print(products)
     }

Alamofire网络调用不在后台线程中运行

1 个答案: