Question

I am trying to convert previously objective C code which is without ARC into ARC. I am fallowing the procedure like in Xcode: File > Edit > Refactor > Convert to ARC.

But I am not able to convert it, because it’s generating lots of errors. I searched about this; I am trying to change the build settings in Xcode Target.

Answer 1

The Convert to ARC tool is not a magic bullet that makes your project suddenly ARC ready. What the tool is does is remove all of your calls to things like release & retain, it can also take care of switching some autorelease pools to the new @auto release {} style.
Before it does any of this it runs a pre-flight script to look for stuff that is too complicated for it to figure out and flags them as errors so you can go through each one and make the correct fix.

You need to step through each one of those 84 issues and figure out the solution to each one. Most likely there are half a dozen or so kinds of errors that are in multiple places but each occurrence may have a slightly different solution. Xcode may suggest a few possible fixes for some of the errors (any of the errors that show a stop sign with a white square in it have possible fixes, Xcode just doesn’t know which one to use so you need to pick). Some of the issues will be easily solvable with a little help from Google. There will also likely be more errors than that in the end (I converted one project over that each time I fixed errors and tried to convert it reported more).

For the errors that you can’t figure out after doing some research you should post questions about here, make sure to be specific as there are many possible things that could cause issues when converting to ARC.