CODEWITHSUNDEEP
iosobjective-canimationuibutton
EthanP
EthanP

Reputation: 1703

Changing title of UIButton using animationWithDuration has no delay or animation

I have a start button with initial text "Start" hooked up to an action in Interface Builder.

However, the animation starts and finishes instantly, instead of taking 3 + 5 seconds. What is wrong with this code?

@interface ViewController()
@property (weak, nonatomic) IBOutlet UIButton *startButton;
@end

@implementation ViewController

- (IBAction)startPressed:(UIButton *)sender
{
    [UIView animateWithDuration:3 delay:5
        options:UIViewAnimationOptionCurveEaseInOut
        animations:^{
            [self.startButton setTitle:@"New Title" forState:UIControlStateNormal];
        } 
        completion:nil];
}

@end

Update: Of course, these responses are correct. I used Jack Wu's suggestion, though without hiding the text, setTitle makes the button flash back on the screen.

- (IBAction)startPressed:(UIButton *)sender
{
    [UIView animateWithDuration:1.5 delay:5
        options:UIViewAnimationOptionCurveEaseInOut
                     animations:^{ self.startButton.alpha = 0; }
                     completion:^(BOOL c){ if (c) {
        self.startButton.hidden = YES;
        [self.startButton setTitle:@"newTitle" forState:UIControlStateNormal];
        [UIView animateWithDuration:1.5 delay:0 options:UIViewAnimationOptionCurveEaseInOut
                         animations:^{
                             self.startButton.hidden = NO;
                             self.startButton.alpha = 1;
                         }
                         completion:nil];

    }}];
}

Upvotes: 1

Views: 2612

Answers (2)

Duncan C
Duncan C

Reputation: 131418

Title is not an animatable property of UIButton. As others have suggested, you would need to create an animation yourself by doing something like fading out the button, changing the title, and fading it back.

You could also write custom animation code that would take a bitmap snapshot of the button, lay that on top of the current button, change the button title under the bitmap snapshot, then fade out and remove the bitmap. That would give you a cross-fade effect, but it would be a fair amount of work.

Upvotes: 1

Travis
Travis

Reputation: 3369

A button's title is not an animatable property, so you're going to see it return immediately. That's by design. You can find the animatable properties of a UIView in its' documentation. Here's what they are as of today.

@property frame
@property bounds
@property center
@property transform
@property alpha
@property backgroundColor
@property contentStretch

Alternately, you can add two subview labels to your button and cross fade them in your animation.

Upvotes: 4

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