Trying to debug a 'Assertion failure in -[UIActionSheet showInView:]' error

I am working through "Beginning iPad Application Development" and am getting hung up in Chapter 3 where I have created a project that works with an Action Sheet.

As it stands now, my application loads into the simulator just fine with no errors that I am aware of, but as it runs, it crashes with the following errors showing up in the debugger window:

2010-05-31 19:44:39.703 UsingViewsActionSheet[49538:207] *** Assertion failure in -[UIActionSheet showInView:], /SourceCache/UIKit_Sim/UIKit-1145.66/UIAlert.m:7073

2010-05-31 19:44:39.705 UsingViewsActionSheet[49538:207] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Invalid parameter not satisfying: view != nil

'

I am sure that this is the block where the app breaks based upon my use of breakpoints.

//Implement viewDidLoad to do additional setup after loading the view, typically from a nib.

- (void)viewDidLoad { UIActionSheet *action = [[UIActionSheet alloc] initWithTitle:@"This is my Action Sheet!" delegate:self cancelButtonTitle:@"OK" destructiveButtonTitle:@"Delete Message!" otherButtonTitles:@"Option 1", @"Option 2", @"Option 3", nil];

[action showInView:self.view];  // <-- This line seems to trigger the crash....
开发者_JAVA百科[action release];
[super viewDidLoad];

}

Am I missing something obvious, or is there more to the problem than is shown here? I have looked at the abstract for showInView and cannot divine anything there yet.

I appreciate any and all asssitance.

Regards,

Steve O'Sullivan

Within the viewDidLoad method the view is not setup entirely. The window property is not wired up.

NSLog(@"View: %@; Window: %@",[self.view description], [self.view.window description]);

will probably show that window is null/nil.

Depending on your design, you may have luck with simply queueing it on the main thread:

-(void) showMyActionSheet
{
    UIActionSheet *action = [[UIActionSheet alloc] initWithTitle:@"This is my Action Sheet!" delegate:self cancelButtonTitle:@"OK" destructiveButtonTitle:@"Delete Message!" otherButtonTitles:@"Option 1", @"Option 2", @"Option 3", nil]; 
    [action showInView:self.view];
    [action release];
}

- (void)viewDidLoad 
{
    [super viewDidLoad]; 
    [self performSelectorOnMainThread:@selector(showMyActionSheet) withObject:nil waitUntilDone:NO];
}

I've just had the same problem. I was converting an existing iPhone app to run universal. I have several buttons that called UIAlertViews that work fine but I have a button that calls an actionsheet. It was generating the same error. In IB in my ipadview.xib in my view controller i had mislinked "view" to window when i should have linked it to the button. It now works fine. Hope this helps. (ps im a complete novice so forgive if this doesnt help) Neil

I was just working through the same chapter and the book's author addresses it here http://p2p.wrox.com/book-beginning-ipad-application-development/79379-ch-3-usingviews-alert-actionsheet.html though if I were you I would vote Eiko's response as the answer since it accomplishes the behavior the example is going for, whereas the authors has you create a button that you clicked after the application launches to see the sheet.

Just for any late comers to this topic, this is still an issue in 5.0 (9A334) iPad simulator and physical devices (iPads).

The answer by Eiko remains correct.

I have fixed assertion failure for ActionSheet recently like this:

UIWindow* window = [[[UIApplication sharedApplication] delegate] window];
    if ([window.subviews containsObject:self.view]) {
        [action showInView:self.view];
    } else {
        [action showInView:window];
    }

It works fine for me.