分配自定义 URLSessionDelegate 是否会覆盖未实现的方法的默认行为？

Question

在 URLSessionDelegate 的文档中说：

Your URLSession object doesn’t need to have a delegate. If no delegate is assigned, a system-provided delegate is used, and you must provide a completion callback to obtain the data.

我只需要实现如下方法之一：

class SessionDelegate: NSObject, URLSessionTaskDelegate {
    func urlSession(_ session: URLSession, task: URLSessionTask, willPerformHTTPRedirection response: HTTPURLResponse, newRequest request: URLRequest, completionHandler: @escaping (URLRequest?) -> Void) {
        var request = request
        request.httpMethod = task.originalRequest?.httpMethod ?? request.httpMethod
        completionHandler(request)
    }
}

然后像这样初始化我的会话：

self.session = URLSession(configuration: config, delegate: SessionDelegate(), delegateQueue: nil)

对于我没有实现的方法，这会覆盖 "system-provided delegate" 中的任何其他行为吗？

Answer 1

您在 SessionDelegate class 中未覆盖的任何（可选）函数将遵循原始函数的默认实现行为。

为了检查每个函数的默认行为，请参阅头文件中的文档（选项+单击 URLSessionTaskDelegate）或此处：

https://developer.apple.com/documentation/foundation/urlsessiontaskdelegate

分配自定义 URLSessionDelegate 是否会覆盖未实现的方法的默认行为？

Does assigning a custom URLSessionDelegate override default behavior for methods that are not implemented?

foundation

swift

urlsession