类似于如何将实例方法用作仅使用func或立即数闭包的函数的回调中一样，您必须转换
self为void指针，将其存储在上下文中，然后将其转换回闭包中的对象指针：
func checkForConnection() { let host = "reddit.com" var context = SCNetworkReachabilityContext(version: 0, info: nil, retain: nil, release: nil, copyDescription: nil) context.info = UnsafeMutablePointer(Unmanaged.passUnretained(self).toOpaque()) let reachability = SCNetworkReachabilityCreateWithName(nil, host)! SCNetworkReachabilitySetCallback(reachability, { (_, flags, info) in if flags.rawValue == 0 { //internet is not connected } else { //internet became connected let mySelf = Unmanaged<ViewController>.fromOpaque(COpaquePointer(info)).takeUnretainedValue() if mySelf.updateonConnection { mySelf.refreshWallpaper() } } }, &context) SCNetworkReachabilityScheduleWithRunLoop(reachability, CFRunLoopGetMain(), kCFRunLoopCommonModes)}备注：
if flags.rawValue == 0可以表示得稍微优雅一些
if flags.isEmpty，但是您 实际上
应该检查的是
if flags.contains(.Reachable)。
Swift 3的更新（Xpre 8 beta 6）：
func checkForConnection() { let host = "reddit.com" var context = SCNetworkReachabilityContext(version: 0, info: nil, retain: nil, release: nil, copyDescription: nil) context.info = UnsafeMutableRawPointer(Unmanaged.passUnretained(self).toOpaque()) let reachability = SCNetworkReachabilityCreateWithName(nil, host)! SCNetworkReachabilitySetCallback(reachability, { (_, flags, info) in if let info = info { if flags.rawValue == 0 { //internet is not connected } else { //internet became connected let mySelf = Unmanaged<ViewController>.fromOpaque(info).takeUnretainedValue() // ... } } }, &context) SCNetworkReachabilityScheduleWithRunLoop(reachability, CFRunLoopGetMain(), CFRunLoopMode.commonModes.rawValue)}
