Problem removing and re-adding an image file into my iOS4 app bundle_问答_开发者

My problem is something that should be so simple it is mind boggling. When I change the look (in PhotoShop) of an image file that is being stored in my app bundle. My method for replacing the old image in the bundle with the new one is this:

1) remove the old image from the app bundle (choosing to also move to trash) 2) drag the new image into my file hierarchy in xcode (choosing to copy to app directory)

when I do this, the app cannot find the image no matter what I do. The new images have the same name as the old images but none of the image loading methods (imageNamed, imageWithContentsOfFile, nibs) work. (Although I believe nibs also load with imageNamed, i'm not sure).

Is there something that I am missing here? I feel like it should be a relatively simple process but I am having all kinds of trouble. I also make sure to delete the app off of the target device and clean all targets before rebuilding and running after changing the image fi开发者_JS百科les just in case.

Any help would be appreciated.

Thanks

Your problem is probably that the image is not copied to the target. In xcode groups & file pane, fine the node for targets, expand your app target and you'll see Copy Bundle resources expand it and you'll see all the files copied to the default resource bundle when you deploy your app to the sim/device. Only the resources found there will be available to your app. If you don't see your image there you can just drag it there and everything will work.

Now, in order to understand why this might happened we need to look at the different options for adding files to xcode.

When you're adding a file to xcode you are presented with a dialog that includes a few interesting and sometimes overlooked option.

The first - Should the file be copied to the project folder, or should it just point to the file original location. The safest way will be to always copy the files to the project's path. However for images (such in your case) I do it differently. I maintain a separate graphics folder for every app, I save images there (both sources, and final png). When I add an image I do not copy it to the project folder, rather xcode just points to its location. That way I can just edit the image in photoshop, do a rebuild, and the updated image will show up on the phone. Whats important to understand that the directory structure of files you include in the project have almost no meaning, files that appear in the Copy Bundle Resources for the target will always be copied to a single (and flat) bundle/"directory" on the phone. The only exception for this is if you actually add directories to xcode (Personally I recommend against it).

The second option when adding files, is to which targets to add the file. This is the list with checkboxes on the bottom, if when you added the image, your app target wasn't checked the file won't be included in the target Copy bundle resource, and won't be available for the phone.

A few caveats - When using references to files in other location, that location is relative to the project's path, so it's a good idea to keep all the files in directories below the project's root directory. That way you can still copy the entire project to a different location and it will still work.

Great advice above: I thought I would add more for future searches on this topic:

I was adding and removing images to the project just like above:

Remove the old image from the app bundle (choosing to also move to trash).
Drag the new image into my file hierarchy in xcode (choosing to copy to app directory).

However when I tried to drag the new image with the same name to my file hierarchy in xcode I was getting an error that this was not allowed.

Turns out when I was removing the old image Xcode was removing it from the project file hierarchy but the actual file wasnt being removed from the project's root directory.

I solved my problem by removing the image from the project's root directory and added the image again!

Do you put your images in a custom sub-folder? If you just drag in images into the Xcode project tree, if you copy them, the images will be copied to the root of the project directory, instead of the "Images" or other folder you might have set up.

Note that you can right-click on the image in your bundle, select "Get Info..." and reset its location, if it has been moved or copied to a folder you didn't expect.