封装了一个函数，用于弹框

/**

弹框

- parameter title: 标题

- parameter msg: 消息

- parameter btns: 弹框项

*/

func show(title:String,msg:String,btns:[String]?) {

let alert = UIAlertController(title: title,message: msg,preferredStyle: .Alert);

for(var i=0;i<btns?.count;i++) {

let btn = UIAlertAction(title: btns![i],style: .Default) { (UIAlertAction) -> Void in

print(UIAlertAction.title); // 打印选中内容

}

alert.addAction(btn);

}

let btn = UIAlertAction(title: "取消",style:.Destructive) { (UIAlertAction) -> Void in

var choose = -1;

}

alert.addAction(btn);

self.presentViewController(alert,animated: true,completion: nil);

}