Objective C, Thread 1 Program Received Signal SIGABRT

Question

I am trying to compile and run a simple tutorial for an Objective C app using Interface Builder. I am using Xcode 4.0.2 and simulating on iOS (iPhone) 4.3

http://www.switchonthecode.com/tutorials/creating-your-first-iphone-application-with-interface-builder

When I build the project, it builds alright but once the app tries to run it crashes with:

int main(int argc, char *argv[])
{
    NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
    int retVal = UIApplicationMain(argc, argv, nil, @"SimpleUIAppDelegate");
    [pool release];
    return retVal;
}

I get the error on line 4: int retVal = UI... Thread 1: Program Received Signal "SIGABRT".

If the other files of this project need to be posted for clarity, I can do that.

Thanks!

Edit:

SimpleUIViewController.h:

#import <UIKit/UIKit.h>

@interface SimpleUIViewController : UIViewController <UITextFieldDelegate> {
    UITextField *textInput;
    UILabel *label;
    NSString *name;
}

@property (nonatomic, retain) IBOutlet UITextField *textInput;
@property (nonatomic, retain) IBOutlet UILabel *label;
@property (nonatomic, copy) NSString *name;

- (IBAction)changeGreeting:(id)sender;

@end

SimpleUIViewController.m:

#import "SimpleUIViewController.h"

@implementation SimpleUIViewController

@synthesize textInput;
@synthesize label;
@synthesize name;

- (IBAction)changeGreeting:(id)sender {
    self.name = textInput.text;

    NSString *nameString = name;
    if([nameString length] == 0) {
        nameString = @"Inigo Montoya";
    }
    NSString *greeting = [[NSString alloc] 
                          initWithFormat:@"Hello, my name is %@!", nameString];
    label.text = greeting;
    [greeting release];
}

- (BOOL)textFieldShouldReturn:(UITextField *)theTextField {
    if(theTextField == textInput) {
        [textInput resignFirstResponder];
    }
    return YES;
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning]; 
    // Release anything that's not essential, such as cached data
}

- (void)dealloc {
    [textInput release];
    [label release];
    [name release];
    [super dealloc];
}

@end

Error message:

This GDB was configured as "x86_64-apple-darwin".Attaching to process 2668.
2011-06-09 11:20:21.662 InterfaceBuilder[2668:207] Unknown class InterfaceBuilderAppDelegate_iPhone in Interface Builder file.
2011-06-09 11:20:21.666 InterfaceBuilder[2668:207] *** Terminating app due to uncaught     exception 'NSUnknownKeyException', reason: '[<UIApplication 0x4b1a900>     setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key  textInput.'
*** Call stack at first throw:
(
    0   CoreFoundation                      0x00dc25a9 __exceptionPreprocess + 185
    1   libobjc.A.dylib                     0x00f16313 objc_exception_throw + 44
    2   CoreFoundation                      0x00dc24e1 -[NSException raise] + 17
    3   Foundation                          0x00794677 _NSSetUsingKeyValueSetter + 135
    4   Foundation                          0x007945e5 -[NSObject(NSKeyValueCoding) setValue:forKey:] + 285
    5   UIKit                               0x0021030c -[UIRuntimeOutletConnection connect] + 112
    6   CoreFoundation                      0x00d388cf -[NSArray makeObjectsPerformSelector:] + 239
    7   UIKit                               0x0020ed23 -[UINib instantiateWithOwner:options:] + 1041
    8   UIKit                               0x00210ab7 -[NSBundle(UINSBundleAdditions) loadNibNamed:owner:options:] + 168
    9   UIKit                               0x0001617a -[UIApplication _loadMainNibFile] + 172
    10  UIKit                               0x00016cf4 -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 291
    11  UIKit                               0x00021617 -[UIApplication handleEvent:withNewEvent:] + 1533
    12  UIKit                               0x00019abf -[UIApplication sendEvent:] + 71
    13  UIKit                               0x0001ef2e _UIApplicationHandleEvent + 7576
    14  GraphicsServices                    0x00ffb992 PurpleEventCallback + 1550
    15  CoreFoundation                      0x00da3944 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 52
    16  CoreFoundation                      0x00d03cf7 __CFRunLoopDoSource1 + 215
    17  CoreFoundation                      0x00d00f83 __CFRunLoopRun + 979
    18  CoreFoundation                      0x00d00840 CFRunLoopRunSpecific + 208
    19  CoreFoundation                      0x00d00761 CFRunLoopRunInMode + 97
    20  UIKit                               0x000167d2 -[UIApplication _run] + 623
    21  UIKit                               0x00022c93 UIApplicationMain + 1160
    22  InterfaceBuilder                    0x000027ff main + 127
    23  InterfaceBuilder                    0x00002775 start + 53
    24  ???                                 0x00000001 0x0 + 1
)
terminate called after throwing an instance of 'NSException'
sharedlibrary apply-load-rules all
Current language:  auto; currently objective-c
(gdb) 

Im new to obj-c, and have absolutely no idea what I'm looking at in regards to that error message. Any help?

Solution 1

You have an error in your NIB/XIB file.

It looks like you have previously attached an IBOutlet (textInput) and now the connection is broken. You should double check all connections in Interface Builder.

Solution 2

It's likely that you have set the type of 'File's Owner' incorrectly to UIViewController in your SimpleUIViewController's xib. Please set it to SimpleUIViewController in identity inspector pane.

Solution 3

Now I see it! Your crash report says:

Unknown class InterfaceBuilderAppDelegate_iPhone

So, it seems that you set your App Delegate in IB to this class, but this class is not available in your project. Check this. Either you misspelled the class name or you should add the relevant class to your project.

Highly likely, your text field is connected to this app delegate.

Have you connected your text field in Interface Builder to the SimpleUIViewController outlet?

Since it seems from the tutorial that you are not using MainWindow.xib, I would say that your project is missing running the proper delegate. Try making this change in your main:

int retVal = UIApplicationMain(argc, argv, nil, @"SimpleUIAppDelegate");

If my hypothesis is right, that should move your forward.

Solution 4

To fix it, load the XIB in Interface Builder, select the File Inspector tab, and uncheck Use autolayout. Alternatively, you can target iOS 6.0+-only devices and change the minimum target, if you absolutely must have autolayout.

NSLayoutConstraint SIGABRT on iPad

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