使 UIAlertView Button 触发功能 On Press

Question

目前，我正在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];

如何获取它，以便当按下“确定”时，它会触发一个函数，例如 -(void)submitData

Answer 1

注意：

重要： UIAlertView 在 iOS 8 中已被弃用。（请注意，UIAlertViewDelegate 也已被弃用。）要在 iOS 8 及更高版本中创建和管理警报，请改为将 UIAlertController 与UIAlertControllerStyleAlert 的首选样式。

请查看此教程

“已弃用”是什么意思？？？

Objectvie 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

    }

}

斯威夫特

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

如果您使用未在类接口中声明的多个 UIAlertView 实例，您还可以设置一个标记来标识委托方法中的实例，例如：

在类文件 myClass.m 顶部的某个位置

#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
    }
}

Answer 3

您需要在分配alertview时设置委托，然后使用UIAlertViewDelegate方法之一来调用您自己的方法，例如：

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

- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex
{
    [self submitData];
}

Answer 4

在显示之前，您需要为 UIAlertView 设置 delegate。然后在委托回调中进行如下工作：

-(void)alertView:(UIAlertView*)alert didDismissWithButtonIndex:(NSInteger)buttonIndex;
{
    if ([[alert buttonTitleAtIndex] isEqualToString:@"Do it"]) {
        // Code to execute on Do it button selection.
    }
}

我的 CWUIKit 项目位于 https://github.com/Jayway/CWUIKit 对 UIAlertView 进行了补充，允许您使用块执行相同的操作。重复使用相同的操作来创建、显示和处理警报：

[[UIAlertView alertViewWithTitle:@"My Title"
                         message:@"The Message"
               cancelButtonTitle:@"Cancel"
  otherTitlesAndAuxiliaryActions:@"Do it", 
                                 ^(CWAuxiliaryAction*a) {
                                    // Code to execute on Do it button selection.
                                 }, nil] show];

Answer 5

如果你想使用块也可以使用 MKAdditions 来实现即使对于多个 UIAlertView，这也很容易。

只需使用与此示例类似的代码：

[[UIAlertView alertViewWithTitle:@"Test" 
                        message:@"Hello World" 
              cancelButtonTitle:@"Dismiss" 
              otherButtonTitles:[NSArray arrayWithObjects:@"First", @"Second", nil]
                      onDismiss:^(int buttonIndex)
 {
     NSLog(@"%d", buttonIndex);
 }
 onCancel:^()
 {
     NSLog(@"Cancelled");         
 }
 ] show];

您可以在本教程中找到更多信息：http://blog.mugunthkumar.com/coding/ios-code-block-based-uialertview-and-uiactionsheet

Answer 6

更多说明，

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex
    {
       //handles title you've added for cancelButtonTitle
        if(buttonIndex == [alertView cancelButtonIndex]) {
            //do stuff
        }else{
           //handles titles you've added for otherButtonTitles
            if(buttonIndex == 1) {
                // do something else
            }
            else if(buttonIndex == 2) {
                // do different thing
            }
        }
    }

示例

UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Need your action!" 
message:@"Choose an option to continue!" delegate:self cancelButtonTitle:@"Not Need!" 
otherButtonTitles:@"Do Something", @"Do Different", nil];
[alert show];

（这是 iOS7 屏幕截图）

Answer 7

从 iOS8 Apple 提供新的 UIAlertController 类，您可以使用它来代替现已弃用的 UIAlertView，它也在折旧消息中说明

UIAlertView 已弃用。将 UIAlertController 与首选样式结合使用
改为 UIAlertControllerStyleAlert

所以你应该使用这样的东西

目标C

UIAlertController * alert = [UIAlertController
                alertControllerWithTitle:@"Title"
                                 message:@"Message"
                          preferredStyle:UIAlertControllerStyleAlert];

   UIAlertAction* yesButton = [UIAlertAction
                        actionWithTitle:@"Yes, please"
                                  style:UIAlertActionStyleDefault
                                handler:^(UIAlertAction * action) {
                                    //Handle your yes please button action here
                                }];

   UIAlertAction* noButton = [UIAlertAction
                            actionWithTitle:@"No, thanks"
                                      style:UIAlertActionStyleDefault
                                    handler:^(UIAlertAction * action) {
                                       //Handle no, thanks button                
                                    }];

   [alert addAction:yesButton];
   [alert addAction:noButton];

   [self presentViewController:alert animated:YES completion:nil];

斯威夫特

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)