FileThumbnail

gistfile1.txt

    NSArray *fileURLs = [[NSFileManager defaultManager] contentsOfDirectoryAtURL:self.url
                                                      includingPropertiesForKeys:[NSArray array]
                                                                         options:0
                                                                           error:nil];
    
    [fileURLs enumerateObjectsUsingBlock:^(NSURL *fileURL , NSUInteger idx, BOOL *stop) {
        NSImage *elementIcon = [[NSWorkspace sharedWorkspace] iconForFile:[fileURL path]];
        CFStringRef fileExtension = (__bridge CFStringRef)[fileURL pathExtension];
        CFStringRef fileUTI = UTTypeCreatePreferredIdentifierForTag(kUTTagClassFilenameExtension, fileExtension, NULL);
        if (UTTypeConformsTo(fileUTI, kUTTypeImage)) {
           // needs QuickLook.framework #import <QuickLook/QuickLook.h>
            NSDictionary *options = [NSDictionary dictionaryWithObject:[NSNumber numberWithBool:YES]
                                                                forKey:(NSString *)kQLThumbnailOptionIconModeKey];
            CGImageRef ref = QLThumbnailImageCreate(kCFAllocatorDefault, (__bridge CFURLRef)fileURL,
                                                    CGSizeMake(50, 50), (__bridge CFDictionaryRef)options);
            elementIcon = [[NSImage alloc] initWithCGImage:ref size:CGSizeMake(50, 50)];
        }
        CFRelease(fileUTI);
    }];