在iOS上从网页请求BLOB

Question

I have a BLOB image stored in a MySQL database, of which I would like to use in my iOS Application. I have created a PHP file to retrieve the BLOB from the database, but I am unsure of what I need to do to get the BLOB into my app.

Please can you give me an example, or point me in the direction of doing so?

Thanks in advanced!

Answer 1

Use ASIIHTTPRequest to request the BLOB data from that PHP page.

With the BLOB data, convert it to a UIImage.

- (void) getBlobData:(NSURL *) url {
    NSURL *url = [NSURL URLWithString:url];
    __block ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
    [request setCompletionBlock:^{
       NSData *blobData = [request responseData];
       UIImage *blobImage = [UIImage imageWithData:blobData] retain];
       [someImageView performSelectorOnMainThread:@selector(setImage:)
       withObject:blobImage 
       waitUntilDone:YES];
    }];

    [request setFailedBlock:^{
      NSError *error = [request error];
    }];
    [request startAsynchronous];
}

Alternatively, you could use Grand Central Dispatch (GCD) to send a request to the web-page in order to receive the blob:

- (void) getBlobData:(NSURL *) url {

    dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0ul); 
    dispatch_async(queue, ^{  
        NSData *blobData = [NSData dataWithContentsOfURL:url];       
        UIImage *blobImage = [UIImage imageWithData:blobData];
        dispatch_sync(dispatch_get_main_queue(), ^{
             [someImageView setImage:blobImage];
         });
     }); 
}