从另一个 GCD 队列中捕获 NSNotification

Question

我是运行使用此代码的后台进程：

func launchTor(hashedPassword hash : String) {
    dispatch_async(dispatch_get_global_queue(QOS_CLASS_BACKGROUND, 0)) {
    // Do some stuff here
    let observer = NSNotificationCenter.defaultCenter().addObserverForName("AppTerminates", object: nil, queue: nil) {
            notification -> Void in
            print("Terminating...")
            // Do smh here
        }
    }
    // Just some more stuff
}

有没有办法指定需要捕获通知的队列（GCD）？

Answer 1

- addObserverForName:object:queue:usingBlock: method is an extra feature provided by NSOperationQueue class 基于 Grand Central Dispatcher：

Operation queues use the libdispatch library (also known as Grand Central Dispatch) to initiate the execution of their operations.

（从NSOperationQueue class参考开始）

如果有原因（例如不同的行为或教育目的），可以重新实现此功能，否则可能值得切换到 NSOperationQueue 而不是裸 GCD。

从另一个 GCD 队列中捕获 NSNotification

Catch NSNotification from another GCD queue

swift

cocoa

grand-central-dispatch

nsnotifications