使UIAlertView按钮触发功能按下

Question

目前我使用以下代码来呈现UIAlertView:

UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Today's Entry Complete"
                        message:@"Press OK to submit your data!" 
                       delegate:nil 
              cancelButtonTitle:@"OK" 
              otherButtonTitles: nil];
    [alert show];
    [alert release];

如何获得它,以便当按下"确定"时,它会触发一个功能,比方说 -(void)submitData

Answer 1

注意:

重要提示:在iOS 8中不推荐使用UIAlertView.(请注意,UIAlertViewDelegate也已弃用.)要在iOS 8及更高版本中创建和管理警报,请使用UIAlertController,其优先级为UIAlertControllerStyleAlert.

请查看这个教程

"弃用"是指???

对象C

.h文件

    @interface urViewController : UIViewController <UIAlertViewDelegate> {

.m文件

// Create Alert and set the delegate to listen events
UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Today's Entry Complete"
                                                message:@"Press OK to submit your data!"
                                               delegate:self
                                      cancelButtonTitle:nil
                                      otherButtonTitles:@"OK", nil];

// Set the tag to alert unique among the other alerts.
// So that you can find out later, which alert we are handling
alert.tag = 100;

[alert show];


//[alert release];


-(void) alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex{


    // Is this my Alert View?
    if (alertView.tag == 100) {
        //Yes


    // You need to compare 'buttonIndex' & 0 to other value(1,2,3) if u have more buttons.
    // Then u can check which button was pressed.
        if (buttonIndex == 0) {// 1st Other Button

            [self submitData];

        }
        else if (buttonIndex == 1) {// 2nd Other Button


        }

    }
    else {
     //No
        // Other Alert View

    }

}

迅速

Swifty方式是使用新的UIAlertController和闭包:

    // Create the alert controller
    let alertController = UIAlertController(title: "Title", message: "Message", preferredStyle: .Alert)

    // Create the actions
    let okAction = UIAlertAction(title: "OK", style: UIAlertActionStyle.Default) {
        UIAlertAction in
        NSLog("OK Pressed")
    }
    let cancelAction = UIAlertAction(title: "Cancel", style: UIAlertActionStyle.Cancel) {
        UIAlertAction in
        NSLog("Cancel Pressed")
    }

    // Add the actions
    alertController.addAction(okAction)
    alertController.addAction(cancelAction)

    // Present the controller
    self.presentViewController(alertController, animated: true, completion: nil)

Answer 2

如果您正在使用未在类接口中声明的多个UIAlertView实例,则还可以设置标记以标识委托方法中的实例,例如:

在你的类文件myClass.m之上的某个地方

#define myAlertViewsTag 0

创建UIAlertView:

UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"My Alert"
    message:@"please press ok or cancel"
    delegate:self
    cancelButtonTitle:@"Cancel"
    otherButtonTitles:@"OK", nil];
alert.tag = myAlertViewsTag;
[alert show];
[alert release];

委托方法:

-(void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex {
    if (alertView.tag == myAlertViewsTag) {
        if (buttonIndex == 0) {
            // Do something when cancel pressed
        } else {
            // Do something for ok
        }
    } else {
        // Do something with responses from other alertViews
    }
}