UIActionSheet 在 iPad 上崩溃/而非 iPhone

当我查看控制台时，我收到此消息

2010-09-18 17:04:05.284 Wasted Time[8998:207] *** Assertion failure in -[UIActionSheet showInView:], /SourceCache/UIKit_Sim/UIKit-1145.66/UIAlert.m:7073
2010-09-18 17:04:05.286 Wasted Time[8998:207] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid parameter not satisfying: view != nil'
2010-09-18 17:04:05.286 Wasted Time[8998:207] Stack: (
    42272848,
    43430700,
    42010379,
    811796,
    3796273,
    3862560,
    9631,
    3616645,
    3688229,
    3682846,
    3690662,
    3686119,
    4983946,
    71264534,
    71263781,
    71207378,
    71206706,
    3003734,
    3030334,
    3011831,
    3043800,
    51265916,
    41552028,
    41547944,
    3002913,
    3036018,
    8314
)
terminate called after throwing an instance of 'NSException'
  

代码如下：

- (void)viewDidLoad {
    BOOL    continueYesNo;
    NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
    continueYesNo = [prefs boolForKey:@"keyContinueMeeting"];   
    if (continueYesNo) {
        NSString *message_continue = [[NSString alloc] initWithFormat:@"Do you want to Continue the Prior Meeting"];
        UIActionSheet *actionSheet = [[UIActionSheet alloc] 
            initWithTitle:message_continue 
            delegate:self
            cancelButtonTitle:@"Reset" 
            destructiveButtonTitle:@"Continue"
            otherButtonTitles:nil];
        [actionSheet showInView:self.view];
        [actionSheet release];
        [message_continue release];
    }
}

它在 iPhone 和 iPhone 模拟器中都运行良好，但在 iPad 模拟器中崩溃。

错误消息显示：

无效参数不满足：view != nil

可能来自这一行：

[actionSheet showInView:self.view];

既然你说这适用于 iPhone，但不适用于 iPad，这意味着 iPad 到达此行的代码路径可能与 iPhone 到达此行的代码路径不同。这意味着视图控制器的view属性可能未针对 iPad 设置。

我的猜测：你忘了连接view此视图控制器正在使用的 xib iPad 版本的 Interface Builder 中的插座。