Question

I am downloaded images using the below code, but whenever I try to display them nothing shows up. I have tested the downloading of the images to my desktop from the app (in simulator) and all the images are created just fine. So I know they are being saved into the App’s Documents directory.

Any ideas on what I am doing wrong?

Download Image Code:

-(void)saveThumbnails:(NSMutableArray *)thumbnails{
    for(NSNumber *videoID in thumbnails){
        // Get an image from the URL below
        NSURL *thumbnailURL = [self generateThumbnailURL:[videoID intValue]];
        UIImage *image = [[UIImage alloc] initWithData:[NSData dataWithContentsOfURL:thumbnailURL]];

        NSLog(@"%f,%f",image.size.width,image.size.height);

        // Let's save the file into Document folder.
        // You can also change this to your desktop for testing. (e.g. /Users/kiichi/Desktop/)
        NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);//Find Application's Document Directory
        NSString *documentsDirectory = [paths objectAtIndex:0];
        NSString *dataPath = [documentsDirectory stringByAppendingPathComponent:@"DownloadedThumbnails"];
//        NSString *dataPath = @"/Users/macminidemo/Desktop/gt";//DEBUG SAVING IMAGE BY SAVING TO DESKTOP FOLDER

        //Check if Sub-directory exists, if not, try to create it
        if (![[NSFileManager defaultManager] fileExistsAtPath:dataPath]){
            NSError* error;
            if([[NSFileManager defaultManager] createDirectoryAtPath:dataPath withIntermediateDirectories:NO attributes:nil error:&error]){
                NSLog(@"New Folder Created!");
            }
            else
            {
                NSLog(@"[%@] ERROR: attempting to write create new directory", [self class]);
                NSAssert( FALSE, @"Failed to create directory maybe out of disk space?");
            }
        }
        NSArray *splitFilename = [[self generateThumbnailFilename:[videoID intValue]] componentsSeparatedByString:@"."];//Break Filename Extension Off (not always PNGs)
        NSString *subString = [splitFilename objectAtIndex:0];
        NSString *formattedFilename = [NSString stringWithFormat:@"%@~ipad.png",subString];
        NSString *localFilePath = [dataPath stringByAppendingPathComponent:formattedFilename];
        NSData *imageData = [NSData dataWithData:UIImagePNGRepresentation(image)];
        [imageData writeToFile:localFilePath atomically:YES];
        NSLog(@"Image: %@ Saved!",formattedFilename);
    }
}

Display Image Code:

if(currentVideo.thumbnail!=(id)[NSNull null] || ![currentVideo.thumbnail isEqualToString:@"missing_image.png"]){
    NSArray *splitFilename = [currentVideo.thumbnail componentsSeparatedByString:@"."];//Break Filename Extension Off (not always PNGs)
    NSString *subString = [splitFilename objectAtIndex:0];
    NSString *formattedFilename = [NSString stringWithFormat:@"%@~ipad.png",subString];

    UIImage *thumbnailImage = [UIImage imageNamed:formattedFilename];

    NSLog(@"Image Name: %@",formattedFilename);
    [videoThumbnail setImage:thumbnailImage];
    [buttonVideo addSubview:videoThumbnail];
}else{
    UIImage *thumbnailImage = [UIImage imageNamed:@"video-details-thumbnail"];
    [videoThumbnail setImage:thumbnailImage];
    [buttonVideo addSubview:videoThumbnail];
}

*And there are no issues displaying the buttonVideo or anything like that. I have tested just setting a test image and that one display just fine (i.e. the “else” statement when run individually works just fine using the default thumbnail)

Answer 1

The documentation for imageNamed says that it works with files that are in the app’s main bundle. This suggests to me that it’s only appropriate for images that are supplied as in-app resources. Try imageWithContentsOfFile: to get at the content of the documents directory.