Confusing EXC_BAD_ACESS error !

So what does the compiler tell you when do an "Analyze"?
Have you turned on all compiler warnings that make sense?

 

In your build settings, there are about two dozen warnings that you can turn on. Things like uninitialized variables and so on. But if you run your app from Xcode, it will stop in the debugger when that error happens, and you can look at the variables at that time, which methods were called, and so on.

The very first thing that you should do is to set a breakpoint on the first statement of FieldAndXPathQuery, and then step go through the code step by step, looking at the contents of variables after each step, and finding out what doesn't work the way you think it should work.

 

Did it stop at the break point? Inside your method? What was the call stack? Or did it crash before reaching the break point? Which means your action method isn't called, so check your connection in interface builder.

try / catch isn't going to help at all. The only place where using try / catch is appropriate in Objective-C is when working with distributed objects, which you are not. Outside that area, any exception thrown is a bug in your application that needs to be fixed.

 

I'm not on a Mac right now so I can't run your program but if you're managing your memory manually, you're likely getting the error because you're not properly managing your retain/release options.

http://loufranco.com/blog/files/Understanding-EXC_BAD_ACCESS.html

 

Thanks all guys,

Actually the problem was this.

in a class i initialized my NSDictionary object in this way -> [NSMutableDictionary dictionary]

in that class its fine, but i inherited that class for another class. so since it became super class it could not work with that kind of initialization!

Thanks to all.

 

You weren't trying to subclass NSDictionary were you? That's not a good idea. The better approach is to use composition to extend the functionality of a custom NSObject that adds the required functionality to a standard NSDictionary.

It looks like you're improving at debugging your own problems and writing better questions.