Any way to get a Cached UIImage from my 'Documents' directory?

Question

I know that the -imageNamed: method returns a Cached UIImage, but the problem is that my image file is stored in \'Documents\', and the -imageNamed: method seems to only search

Answer 1

The simplest way would be an NSMutableDictionary storing the cached images and a clear cache method:

@interface UIImage (CacheExtensions)
+ (id)cachedImageWithContentsOfFile:(NSString *)path;
+ (void)clearCache;
@end

static NSMutableDictionary *UIImageCache;

@implementation UIImage (CacheExtensions)
+ (id)cachedImageWithContentsOfFile:(NSString *)path
{
    id result;
    if (!UIImageCache)
        UIImageCache = [[NSMutableDictionary alloc] init];
    else {
        result = [UIImageCache objectForKey:path];
        if (result)
            return result;
    }
    result = [UIImage imageWithContentsOfFile:path];
    [UIImageCache setObject:result forKey:path];
    return result;
}
+ (void)clearCache
{
    [UIImageCache removeAllObjects];
}
@end

Note: you should call +[UIImage clearCache] from your didReceiveMemoryWarning method. Also, clearCache will invalidate all objects in the cache, not just unused items; a UIImage subclass and more complicated caching mechanism would be required to remedy this.