当NSURLConnection时,swift UIActivityIndi​​catorView

Question

我知道如何动画UIActivityIndi​​catorView我知道如何建立连接 NSURLConnection.sendSynchronousRequest

但我不知道如何动画UIActivityIndi​​catorView WHILE与之建立联系 NSURLConnection.sendSynchronousRequest

谢谢

Answer 1

不要sendSynchronousRequest在主线程中使用(因为它会阻止你运行它的任何线程).您可以使用sendAsynchronousRequest,或者,如果NSURLConnection已经弃用,您应该使用NSURLSession,然后您尝试使用UIActivityIndicatorView应该可以正常工作.

例如,在Swift 3中:

let indicator = UIActivityIndicatorView(activityIndicatorStyle: .gray)
indicator.center = view.center
view.addSubview(indicator)
indicator.startAnimating()

URLSession.shared.dataTask(with: request) { data, response, error in
    defer {
        DispatchQueue.main.async {
            indicator.stopAnimating()
        }
    }

    // use `data`, `response`, and `error` here
}

// but not here, because the above runs asynchronously

或者,在Swift 2中:

let indicator = UIActivityIndicatorView(activityIndicatorStyle: .Gray)
indicator.center = view.center
view.addSubview(indicator)
indicator.startAnimating()

NSURLSession.sharedSession().dataTaskWithRequest(request) { data, response, error in
    defer {
        dispatch_async(dispatch_get_main_queue()) {
            indicator.stopAnimating()
        }
    }

    // use `data`, `response`, and `error` here
}

// but not here, because the above runs asynchronously