没有输入参数的完成处理程序

Created: November-22, 2018

func sampleWithCompletion(completion:@escaping (()-> ())){
    let delayInSeconds = 1.0
    DispatchQueue.main.asyncAfter(deadline: DispatchTime.now() + delayInSeconds) {
        
        completion()
        
    }
}

//Call the function
sampleWithCompletion {
    print("after one second")
}