贡献者:赵大财
博客: GitHub: 邮箱: dacai_zhao@163.com QQ:327532817 =============================DispatchQueue.main.asyncAfter(deadline: .now() + 0.9) { self.currentView.isUserInteractionEnabled = true } func hideView(afterDelay:CGFloat) { let after = TimeInterval(afterDelay) DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + Double(Int64(after * Double(NSEC_PER_SEC))) / Double(NSEC_PER_SEC), execute: { self.maskview.removeFromSuperview() }) } DispatchQueue.global().async { //耗时操作DispatchQueue.main.async { //刷新UI}} // 创建一个队列组let group = DispatchGroup() // A任务入组group.enter()// A任务异步操作DispatchQueue.global().async(group: group, execute: DispatchWorkItem(block: { sleep(2) print("download task A ...") // 出组 group.leave()}))// B任务入组group.enter()// B任务异步操作DispatchQueue.global().async(group: group, execute: DispatchWorkItem(block: { sleep(2) print("download task B ...") // 出组 group.leave()}))// 主线程监听，只有当队列组中没有任务，才会执行闭包。如果多次调用该方法，每次都会去检查队列组中是否有任务，如果没有任务才执行group.notify(queue: DispatchQueue.main) { print("complete!")}