Enable and Debug Zombie objects in iOS using Xcode

问题:

I have an iOS(7.1) app which crashes due to EXC_BAD_ACCESS. If I am not wrong, this happens due to the use of an object which is already de-allocated. After a bit of searching, I found out that enabling Zombie objects help to pin point the line of error. As I am using xcode 5.1.1, I have done the following to Enable Zombie Objects.

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And then, checking the Enable Zombie Objects checkbox,

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Then I went to Instruments panel, selected Zombies,clicked Profile and got this,

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Now the simulator (in the left background), which had a button and a textfield is running blank and also I can't understand anything on the Instruments panel.

What should be the next step? I mean how can I get the lines which are causing the bad access? I am stuck on this for hours but still couldn't find the procedure.

Any help is appreciated.

回答1:

Accessing a deallocated object is not the only reason you would get EXC_BAD_ACCESS. Other causes of bad access errors include accessing nil pointers and going past the bounds of an array.

Looking at your screenshots, you are not using a deallocated object. If you were using a deallocated object, the Zombies template in Instruments would let you know. Instruments would show a message similar to the following:

Your next step should be to set an exception breakpoint in Xcode. When your app crashes, Xcode will pause your app at the point where the crash occurs. To set an exception breakpoint, open the breakpoint navigator by choosing View > Navigators > Show Breakpoint Navigator. Click the + button at the bottom of the navigator and choose Add Exception Breakpoint.