使用UIAlertView檢測按鈕單擊

Question

我試圖在按下按鈕時調用併發出警報。我使用這個：

-(IBAction)Add { 
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle: @"add button pressed" 
                message:@"Add to record" 
                delegate:nil  
              cancelButtonTitle:@"Cancel" 
              otherButtonTitles:@"OK", nil ]; 
    [alert show]; 
    [alert release];  
} 

好的，這裏沒問題，兩個按鈕上來，確定並取消。現在我想檢測哪個按鈕被按下我使用：

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex { 
    // the user clicked one of the OK/Cancel buttons 
    if (buttonIndex == 0) 
    { 
     //just to show its working, i call another alert view 
     UIAlertView *alert = [[UIAlertView alloc] initWithTitle: @"OK WORKIng well" 
                 message:@"no error"                           delegate:nil 
               cancelButtonTitle:@"IWORKS" 
               otherButtonTitles:@"NO PRB", nil]; 
     [alert show]; 
     [alert release];  


    } 
    else 
    { 
     NSLog(@"cancel");  
    } 
} 

現在，這是問題。我無法檢測到哪個按鈕被按下;第二個alertview不顯示。我已經通過代碼檢查了幾次，似乎沒有任何問題。沒有錯誤/警告。

Answer 1

要檢測按鈕點擊，警報視圖必須具有關聯的委託人，例如，

UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"add button pressed" 
               message:@"Add to record" 
               delegate:self // <------ 
             cancelButtonTitle:@"Cancel" 
             otherButtonTitles:@"OK", nil]; 

Answer 2

0的buttonIndex是取消按鈕。我會建議使用：

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex { 
if (buttonIndex == 0) 
{ 
     NSLog(@"cancel"); 
} 
else 
{ 
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"OK works" message:@"no error" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];                            
    [alert show]; 
    [alert release];   
} 
} 

Answer 3

如果你喜歡你的代碼更清潔和委託無依賴，你應該嘗試阻撓執行UIAlertView中的：

https://github.com/steipete/PSAlertView

塊僅支持iOS 4+設備。

Answer 4

這是你的代碼，我使用並添加了一些我的代碼也。 **

-(IBAction) Add 
{ 

      UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"add button pressed" 

                 message:@"Add to record" 
                 delegate:nil  
              cancelButtonTitle:@"Cancel" 
              otherButtonTitles:@"OK", nil]; 

     alert.tag=101;//add tag to alert 
     [alert show]; 
     [alert release];  
} 

現在，當您按下警報按鈕，它會調用clickedButtonAtIndex 但應該爲每個警報一個標識符。所以添加標籤，然後

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

{ 

// the user clicked one of the OK/Cancel buttons 
if(alert.tag=101)  // check alert by tag 
{  

if (buttonIndex == 0) 

    { 

    //just to show its working, i call another alert view 

    UIAlertView *alert = [[UIAlertView alloc] initWithTitle: @"OK WORKIng well" 

                message:@"no error" 
                delegate:nil 
              cancelButtonTitle:@"IWORKS" 
              otherButtonTitles:@"NO PRB", nil]; 

    [alert show]; 
    [alert release];  

} 

else 

{ 
    NSLog(@"cancel");  
} 
} 
} 

希望它有幫助。

Answer 5

我覺得，如果你想顯示在現有的警報視圖按鈕點擊事件的新警報視圖，這將是更好地使用

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

} 

委託方法，而不是

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

} 

Answer 6

1) 
.h file 
@interface MyClassViewController:<UIAlertViewDelegate> 

2) 
.m file 

UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Note" 
               message:@"some message" 
               delegate:self // must be self to call clickedButtonAtIndex 
             cancelButtonTitle:@"Cancel" 
             otherButtonTitles:@"OK", nil]; 


3) 
- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex { 

    if (buttonIndex == [alertView cancelButtonIndex]) { 
    NSLog(@"The cancel button was clicked from alertView"); 
    } 
else { 

} 
}