Exc_Bad_Access Signal Received

EXC_BAD_ACCESS signal received

From your description I suspect the most likely explanation is that you have some error in your memory management. You said you've been working on iPhone development for a few weeks, but not whether you are experienced with Objective C in general. If you've come from another background it can take a little while before you really internalise the memory management rules - unless you make a big point of it.

Remember, anything you get from an allocation function (usually the static alloc method, but there are a few others), or a copy method, you own the memory too and must release it when you are done.

But if you get something back from just about anything else including factory methods (e.g. [NSString stringWithFormat]) then you'll have an autorelease reference, which means it could be released at some time in the future by other code - so it is vital that if you need to keep it around beyond the immediate function that you retain it. If you don't, the memory may remain allocated while you are using it, or be released but coincidentally still valid, during your emulator testing, but is more likely to be released and show up as bad access errors when running on the device.

The best way to track these things down, and a good idea anyway (even if there are no apparent problems) is to run the app in the Instruments tool, especially with the Leaks option.

Thread 1: Program received signal : EXC_BAD_ACCESS

This usually means you're trying to access an object that has already been deallocated.

In order to debug these things, Objective C uses something called "NSZombie" that will keep those objects around so you can at least see what it is that's trying to be called. See this question for some details on how to use it.

EXC_BAD_ACCESS automatic handling

EXC_BAD_ACCESS doesn't generate an exception so you first function doesn't work with the case. It generates a signal SIGSEGV or SIGBUS.

Please refer to Handling unhandled exceptions and signals by Cocoa with Love.

Update

I just checked the source code of LLDB. It might be TARGET_EXC_BAD_ACCESS = 0x91.

In RNBRemote.h:

/* We translate the /usr/include/mach/exception_types.h exception types
   (e.g. EXC_BAD_ACCESS) to the fake BSD signal numbers that gdb uses
   in include/gdb/signals.h (e.g. TARGET_EXC_BAD_ACCESS).  These hard
   coded values for TARGET_EXC_BAD_ACCESS et al must match the gdb
   values in its include/gdb/signals.h.  */

#define TARGET_EXC_BAD_ACCESS      0x91
#define TARGET_EXC_BAD_INSTRUCTION 0x92
#define TARGET_EXC_ARITHMETIC      0x93
#define TARGET_EXC_EMULATION       0x94
#define TARGET_EXC_SOFTWARE        0x95
#define TARGET_EXC_BREAKPOINT      0x96

and in RNBRemote.cpp:

// Translate any mach exceptions to gdb versions, unless they are
// common exceptions like a breakpoint or a soft signal.
switch (tid_stop_info.details.exception.type)
{
    default:                    signum = 0; break;
    case EXC_BREAKPOINT:        signum = SIGTRAP; break;
    case EXC_BAD_ACCESS:        signum = TARGET_EXC_BAD_ACCESS; break;
    case EXC_BAD_INSTRUCTION:   signum = TARGET_EXC_BAD_INSTRUCTION; break;
    case EXC_ARITHMETIC:        signum = TARGET_EXC_ARITHMETIC; break;
    case EXC_EMULATION:         signum = TARGET_EXC_EMULATION; break;
    case EXC_SOFTWARE:
        if (tid_stop_info.details.exception.data_count == 2 &&
            tid_stop_info.details.exception.data[0] == EXC_SOFT_SIGNAL)
            signum = tid_stop_info.details.exception.data[1];
        else
            signum = TARGET_EXC_SOFTWARE;
        break;
}

EXC_BAD_ACCESS signal received when clicking navigation a UIBarButtonItem?

UIButton *btnNext1 =    [UIButton buttonWithType:UIButtonTypeCustom]

and don't release it .Also release Rootview since you are not allocating it.

Program received signal: “EXC_BAD_ACCESS”?

Examine this line:

char *string1

and this line:

scanf("%s", string1);

You have not declared a size for string1, meaning that you will always get an error, fix it with something like this:

char string1[100]

If 100 is the maximum length of your input.

Or read your input character by character.

And, to get rid of the warnings, add #include "string.h" to where your #include statements are.

EXC_BAD_ACCESS signal received

From your description I suspect the most likely explanation is that you have some error in your memory management. You said you've been working on iPhone development for a few weeks, but not whether you are experienced with Objective C in general. If you've come from another background it can take a little while before you really internalise the memory management rules - unless you make a big point of it.

Remember, anything you get from an allocation function (usually the static alloc method, but there are a few others), or a copy method, you own the memory too and must release it when you are done.

But if you get something back from just about anything else including factory methods (e.g. [NSString stringWithFormat]) then you'll have an autorelease reference, which means it could be released at some time in the future by other code - so it is vital that if you need to keep it around beyond the immediate function that you retain it. If you don't, the memory may remain allocated while you are using it, or be released but coincidentally still valid, during your emulator testing, but is more likely to be released and show up as bad access errors when running on the device.

The best way to track these things down, and a good idea anyway (even if there are no apparent problems) is to run the app in the Instruments tool, especially with the Leaks option.

EXC_BAD_ACCESS signal received

Run your code with NSZombieEnabled set. This should tell you if you are over releasing or under retaining somewhere.

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