Blinking UILabel Cocoa Touch

Is it possible to make a blinking UILabel in Cocoa Touch o开发者_Python百科r do I need an UIview with Core Animation for that?

Take Martin's advice, and then have a look at NSTimer to handle the "blink" actions.

+ scheduledTimerWithTimeInterval:target:selector:userInfo:repeats:

All UIViews (including UILabel) has a hidden property which you can toggle on and off to make it "blink".

For fun, I decided to write this subclassing NSOperation.

Excerpt from BlinkingLabelOperation.m

- (void)main {
    SEL update = @selector(updateLabel);
    [self setThreadPriority:0.0];

    while (![self isCancelled]) {
        if (label_ == nil)
            break;

        [NSThread sleepForTimeInterval:interval_];
        [self performSelectorOnMainThread:update withObject:nil waitUntilDone:YES];
    }
}

- (void)updateLabel {
    BlinkingColors *currentColors = nil;

    if (mode_)
        currentColors = blinkColors_;
    else
        currentColors = normalColors_;

    [label_ setTextColor:currentColors.textColor];
    [label_ setBackgroundColor:currentColors.backgroundColor];

    mode_ = !mode_;
}

Sample view controller code:

- (void)viewDidLoad
{
    [super viewDidLoad];

    BlinkingColors *blinkColors = [[BlinkingColors alloc] initWithBackgroundColor:[UIColor whiteColor]
                                                                        textColor:[UIColor redColor]];

    BlinkingLabelOperation *blinkingOp = [[BlinkingLabelOperation alloc] initWithLabel:clickLabel freq:1.0 blinkColors:blinkColors];

    // put the operation on a background thread
    NSOperationQueue *queue = [[[NSOperationQueue alloc] init] autorelease];
    [queue addOperation:blinkingOp];

    [blinkColors release];
}

For a complete listing, you will find it here. Please leave comments and let me know what are your thoughts.