Question

我从库中运行一个我无法看到实现的函数。

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
    someClass.beginService();
});

这个库类调用我的类'委托函数。

class Mine: UIViewController, SomeClassDelegate {

    let someClass = SomeClass();

    override func viewDidLoad () {
        super.viewDidLoad();
        someClass.delegate = self;
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
            self.someClass.beginService();
        });
    }

    func delegateCall () {
        print ("delegateCall is called!");
        // do some stuff
    }
}

然后在日志窗口中每隔1秒定期打印一个单词delegateCall is called!，因为我呼叫self.someClass.beginService();。

问题是，如何终止此线程？我不想诉诸：

class Mine: UIViewController, SomeClassDelegate {

    let someClass = SomeClass();
    var okToRun = false;

    override func viewDidLoad () {
        super.viewDidLoad();
        someClass.delegate = self;
        dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
            self.someClass.beginService();
            okToRun = true;
        });
    }

    func delegateCall () {
        if okToRun {
            print ("delegateCall is called!");
            // do some stuff
        }
    }

    @IBAction func buttonStopTapped (sender: AnyObject) {
        okToRun = false;
    }
}

因为这意味着后台例程仍然有效。

Answer 1

尝试使用无效功能。喜欢

var  thread = dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
            self.someClass.beginService();

你想在哪里停止

thread.invalidate()

如何阻止线程在Swift中无限期运行？

1 个答案: