Question

In loadDidLoad controller call method with thread, like that:

- (void)viewDidLoad {
    [super viewDidLoad];
    NSInvocationOperation *operation = [[NSInvocationOperation alloc] initWithTarget:self selector:@selector(loadImages) object:nil];
    [self.operationQueue addOperation:operation];
    [operation release]; 
}

loadImages method downloading image and show it:

- (void) loadImages {

    @synchronized (self) {
        // download image...
        // ...
        // and next:
        UIImageView *imageView = [imageViews objectAtIndex:currentImageIndex];
        [imageView performSelectorOnMainThread:@selector(setNeedsDisplay) withObject:nil waitUntilDone:YES];
        [imageView performSelectorOnMainThread:@selector(setImage:) withObject:[UIImage imageWithData:imageData] waitUntilDone:YES];
    }
         //...
}

that work if show view first time, next time i must rotate iphone to show images.
why view doesn’t redraw?

---

i tried this code according to advices:

// imageButton is a UIView with button, image and label
NSData   *imageData = [[HttpClient sharedInstance] getResourceWithCache:thumbPath];
[imageButton performSelectorOnMainThread:@selector(setImage:) withObject:[UIImage imageWithData:imageData] waitUntilDone:YES];
[imageButton performSelectorOnMainThread:@selector(setNeedsDisplay) withObject:nil waitUntilDone:YES];
[imageButton drawRect:imageButton.frame];

but do not work.

Answer 1

your problem is in the line

        [imageView performSelectorOnMainThread:@selector(setNeedsDisplay) withObject:nil waitUntilDone:YES];

You would need to call setNeedsDisplay in self.view and not on self, as thats a method for UIView and not UIViewController.

Double check this by subclassing your view and putting a break point in drawRect: , as setNeedsDisplay must call drawRect.