弹框有很多中样式，比如系统的中间弹框，底部弹框还有第三方的MBProgressHuD弹框等等，在本篇文章中小编将带大家一起来探讨一下多种多样的弹框效果。

一、UIAlertController

1.警告框-中间弹框

自IOS8起，建议使用UIAlertController。

   override func viewDidAppear(animated: Bool) {
       let alertController = UIAlertController(title: "系统提示", message: "您确定要离开吗", preferredStyle: UIAlertControllerStyle.Alert)
       let cancelAction = UIAlertAction(title: "取消", style: UIAlertActionStyle.Cancel, handler: nil )
       let okAction = UIAlertAction(title: "确定", style: UIAlertActionStyle.Default) { (ACTION) in
           print("确定")
       }
       alertController.addAction(cancelAction);
       alertController.addAction(okAction);
       self.presentViewController(alertController, animated: true, completion: nil)
   } 

效果图如下：

普通警告框.png

2.使用输入框和密码框的告警框

override func viewDidAppear(animated: Bool) {
    super.viewDidAppear(animated);
    
    let alertController = UIAlertController(title: "系统登录", message: "请输入用户名和密码", preferredStyle: UIAlertControllerStyle.Alert);
    alertController.addTextFieldWithConfigurationHandler { (textField:UITextField!) -> Void in
        textField.placeholder = "用户名";
    }
    alertController.addTextFieldWithConfigurationHandler { (textField:UITextField!) -> Void in
        textField.placeholder = "密码";
        textField.secureTextEntry = true;
    }
    let cancelAction = UIAlertAction(title: "取消", style: UIAlertActionStyle.Cancel, handler: nil )
    let okAction = UIAlertAction(title: "好的", style: UIAlertActionStyle.Default) { (ACTION) -> Void in
        let login = alertController.textFields!.first! as UITextField
        let passWord = alertController.textFields!.last! as UITextField
        print("用户名：\(login.text) 密码：\(passWord.text)");
    }
    alertController.addAction(cancelAction);
    alertController.addAction(okAction);
    self.presentViewController(alertController, animated: true, completion: nil)
}

效果图如下：

使用输入框和密码框的告警框.png

3.底部弹框

自iOS8起，开始用UIAlertController来代替UIActionSheet

 override func viewDidAppear(animated: Bool) {
    let alertController = UIAlertController(title: "系统提示", message: "您确定要删除吗", preferredStyle: .ActionSheet)
    let cancelAction = UIAlertAction(title: "取消", style: .Cancel, handler: nil)
    let deleteAction = UIAlertAction(title: "删除", style: .Destructive, handler: nil)
    let archiveAction = UIAlertAction(title: "保存", style: .Default, handler: nil)
    alertController.addAction(cancelAction)
    alertController.addAction(deleteAction)
    alertController.addAction(archiveAction)
    self.presentViewController(alertController, animated: true, completion: nil)
}

底部弹框.png