Swift3 使用系统UIAlertView方法做吐司效果

/**
*显示弹出信息
*/
class func showAlertMessage(_ str:String,showtime Num:Double){ let alert = UIAlertView(title: str, message: nil, delegate: nil, cancelButtonTitle: nil);
alert.show()
// self.performSelector(#selector(dismissAlert(_:)), withObject: alert, afterDelay: Num)
let dispatchTime: DispatchTime = DispatchTime.now() + Double(Int64(0.10 * Num * Double(NSEC_PER_SEC))) / Double(NSEC_PER_SEC)
DispatchQueue.main.asyncAfter(deadline: dispatchTime, execute: {
dismissAlert(alert)
})
} class func dismissAlert(_ alert:UIAlertView){
alert.dismiss(withClickedButtonIndex: alert.cancelButtonIndex, animated: true)
}