制作按钮UIAlertView执行Segue

Question

我创建了UIAlertView一个动作,它给了我两个选项.我希望用户能够点击按钮并让它执行Segue.

这是我到目前为止的代码:

- (IBAction)switchView:(id)sender
{
    UIAlertView *myAlert = [[UIAlertView alloc]
                            initWithTitle:@"Please Note"
                            message:@"Hello this is my message"
                            delegate:self
                            cancelButtonTitle:@"OK"
                            otherButtonTitles:@"Option 1", @"Option 2", nil];
    [myAlert show];
}

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
    NSString *buttonTitle = [alertView buttonTitleAtIndex:buttonIndex];

    if ([buttonTitle isEqualToString:@"Option 1"]) {



    }
}

Answer 1

是的,一开始并不是很明显,你需要创建一个手动的segue.

选择将执行推送的ViewController(我是推动者),并将手动连接到推送的视图控制器(推送视图控制器).

iOS 8+与Swift

选择新创建的segue,并为其命名(在我的例子中"segue.push.alert",为日志记录的长名称),并在警报的操作中调用perform segue,如:

let alert = UIAlertController(title: "My Alert", message: "Be Alerted. This will trigger a segue.", preferredStyle: .Alert)
alert.addAction(UIAlertAction(title: "Cancel", style: .Cancel, handler: nil))
alert.addAction(UIAlertAction(title: "Segue", style: .Default, handler:
{
    [unowned self] (action) -> Void in

    self.performSegueWithIdentifier("segue.push.alert", sender: self)
}))

presentViewController(alert)

[unowned self]应该小心处理,如果视图控制器可以在动作发生时解除分配,那么你最好[weak self]再做,然后再做self?.performSegue...分配.

老答案

现在,performSegueWithIdentifier:sender:在您的情况下,您可以从视图控制器中轻松调用

// Using enums is entirely optional, it just keeps the code neat.
enum AlertButtonIndex : NSInteger
{
    AlertButtonAccept,
    AlertButtonCancel
};

// The callback method for an alertView
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)index
{
    if (index == AlertButtonAccept)
    {
        [self performSegueWithIdentifier:@"segue.push.alert" sender:self];
    }
}

以这种方式获得segues(而不是直接编码)的优点是,您仍然可以对应用程序流有一个很好的概述,具有混合编码段和加载故事板的segues有点失败的目的.

Answer 2

如果你在故事板中给你的 segue 一个标识符，你可以这样做：

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {
    NSString *buttonTitle = [alertView buttonTitleAtIndex:buttonIndex];

    if ([buttonTitle isEqualToString:@"Option 1"]) {

        [self performSegueWithIdentifier:@"foo" sender:nil];

    }
}