如何在一個IBAction中使用不同的按鈕使用多個UIAlertView？

Question

是否有可能根據不同的條件在同一個IBAction中用不同的按鈕顯示不同的警報？我在IBAction爲一些代碼：

- (IBAction)btnRecommendationTapped:(id)sender { 
UIAlertView *alert = [[UIAlertView alloc] initWithTitle: @"Recommendation" 
                 message: @"It seems that you are interested in the %d of this collection." 
                delegate: nil 
              cancelButtonTitle: nil 
              otherButtonTitles: @"Yes", @"No", nil]; 
[alert show]; 
} 

我想有另一個警報顯示「！很抱歉，我們無法提供任何建議，」用確定按鈕。當條件滿足時，顯示IBAction中的一個顯示這個。

Answer 1

-(IBAction)buttonClicked:(id)sender 
    { 
      if([sender tag]==0) 
     { 
      UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"button 1 clicked" delegate:self 
      cancelButtonTitle:@"Ok" otherButtonTitles:nil, nil]; 
       [alert show]; 
     } 
     else if ([sender tag]==1) 
     { 
      UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"button 2 clicked" delegate:self 
      cancelButtonTitle:@"Ok" otherButtonTitles:nil, nil]; 
       [alert show]; 
     } 
     else if ([sender tag]==2) 
     { 
      UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"button 3 clicked" delegate:self 
      cancelButtonTitle:@"Ok" otherButtonTitles:nil, nil]; 
       [alert show]; 
     } 
} 

Answer 2

嘗試如下：

- (IBAction)btnRecommendationTapped:(id)sender { 
if(condition has fulfilled){ 
UIAlertView *alert = [[UIAlertView alloc] initWithTitle: @"Recommendation" 
                 message: @"It seems that you are interested in the %d of this collection." 
                delegate: nil 
              cancelButtonTitle: nil 
              otherButtonTitles: @"Yes", @"No", nil]; 
[alert show]; 
} 
else{ 
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle: @"Sorry! we are unable to provide any recommendation" 
                 message: nil" 
                delegate: nil 
              cancelButtonTitle: nil 
              otherButtonTitles: @"Ok", nil]; 
[alert show]; 

} 
} 

Answer 3

有幾種不同的方法可以做到這一點。您可以使用if statement，根據條件創建不同的UIAlertView。

選項1：

- (IBAction)btnClicked:(id)sender 
{ 
    UIAlertView *ourAlertView; // Create the local variable, we don't need to create multiple ones we can just set to the one. 
    // This is your if statement to determine if your condition has been met 
    // Whatever that condition is here we're going to assume you have set a BOOL 
    // flag before hand called failed. 
    if(!failed) { 
     ourAlertView = [[UIAlertView alloc] initWithTitle:@"Recommendations" 
                message:@"We recommend..." 
               delegate:self // Very important 
             cancelButtonTitle:@"No" 
             otherButtonTitles:@"Yes", nil]; 
     [ourAlertView setTag:0]; // Would recommend setting a tag to determine which one has been used in the delegate methods. 
    } else { // else if() if you want more then 2 
     ourAlertView = [[UIAlertView alloc] initWithTitle:@"Sorry" 
                message:@"We're sorry..." 
               delegate:self // Very important 
             cancelButtonTitle:@"OK" 
             otherButtonTitles:nil]; 
     [ourAlertView setTag:1]; 
    } 

    [ourAlertView show]; 
} 

第二種辦法很簡單，但我們會做以下，仍使用if statement但我們只建立一個UIAlertView

選項2：

- (IBAction)btnClicked:(id)sender 
{ 
    // We create an empty `UIAlertView` only setting the delegate to self. 
    UIAlertView *ourAlertView = [[UIAlertView alloc] initWithTitle:nil 
               message:nil 
               delegate:self // Very important 
            cancelButtonTitle:nil 
            otherButtonTitles:nil]; 

    if(!failed) { 
     [ourAlertView setTitle:@"Recommendations"]; 
     [ourAlertView setMessage:@"We recommend..."]; 
     [ourAlertView addButtonWithTitle:@"No"]; 
     [ourAlertView addButtonWithTitle:@"Yes"]; 
     [ourAlertView setCancelButtonIndex:0]; 
     [ourAlertView setTag:0]; 
    } else { 
     [ourAlertView setTitle:@"Sorry"]; 
     [ourAlertView setMessage:@"We're sorry..."]; 
     [ourAlertView addButtonWithTitle:@"OK"]; 
     [ourAlertView setCancelButtonIndex:0]; 
     [ourAlertView setTag:1]; 
    } 

    [ourAlertView show]; 
} 

但是最重要的需要的東西（那就是，如果你想讓它正常工作），很多人忘記的是UIAlertViewDelegate。

所以在你.h文件，你必須在@interface設置你需要做的

@interface MySubClass : MySuperClass <UIAlertViewDelegate> 

這將允許您使用以下方法從UIAlertViewDelegate

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex 
- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex 
- (void)alertView:(UIAlertView *)alertView willDismissWithButtonIndex:(NSInteger)buttonIndex 
- (void)alertViewCancel:(UIAlertView *)alertView 
- (BOOL)alertViewShouldEnableFirstOtherButton:(UIAlertView *) 
- (void)didPresentAlertView:(UIAlertView *)alertView 
- (void)willPresentAlertView:(UIAlertView *)alertView 

結帳兩個UIAlertView Apple Documentation和UIAlertViewDelegate Apple Documentation

非常重要否關於UIAlertView的蘋果文檔中有關子類化的問題。

UIAlertView類旨在按原樣使用，不支持子類。這個類的視圖層次是私有的，不能修改