Como posso animar uma propriedade UIBIBLESTTON ALPHA com Monotouch

Question

Eu tenho um UIBUBTTON simples com uma propriedade alfa que gostaria de animar de 1,0F a 0,0F e depois voltar para 1.0F. Isso está basicamente respondendo ao touchdown.

Além disso, há algo de especial que eu preciso fazer se a rotina que estou chamando não estiver no tópico principal (o delegado assíncrono invocado no Threadpool)?

Devo usar a caanimação?

Obrigado!

Answer 1

A menos que alguém se esforce com uma maneira mono de fazê -lo, digo que use:

- (void) pulseButton {
    button.alpha = 0.0;
    [UIView beginAnimations:nil context:button]; {
        [UIView setAnimationDelegate:self];
        [UIView setAnimationDidStopSelector:@selector(makeVisibleAgain:finished:context:)];
        [UIView setAnimationCurve:UIViewAnimationCurveEaseOut];
        [UIView setAnimationDuration:0.50];
        button.alpha = 0.0;
    } [UIView commitAnimations];
}
- (void)makeVisibleAgain:(NSString *)animationID finished:(NSNumber *)finished context:(void *)context
{
    UIButton *button = ((UIButton *) context);
    [UIView beginAnimations:nil context:nil]; {
        [UIView setAnimationDelegate:nil];
        [UIView setAnimationCurve:UIViewAnimationCurveEaseIn];
        [UIView setAnimationDuration:0.5];
        button.alpha = 1.0;
    } [UIView commitAnimations];

}

Answer 2

Obrigado pela postagem de código do iPhone.

A segunda resposta é usar uma variável global e pula os parâmetros para o retorno de chamada. Aqui está o que eu descobri hoje com base na primeira resposta.

private void BeginPulse (Button button)
{
    UIView.BeginAnimations (button+"fadeIn", button.Handle);
    UIView.SetAnimationDelegate (this);
    UIView.SetAnimationDidStopSelector (new MonoTouch.ObjCRuntime.Selector ("makeVisibleAgain:finished:context:"));
    UIView.SetAnimationCurve(UIViewAnimationCurve.EaseOut);
    UIView.SetAnimationDuration (0.5);
     button.Alpha = 0.25f;
    UIView.CommitAnimations ();
}

[Export ("makeVisibleAgain:finished:context:")]
private void EndPulse (NSString animationId, NSNumber finished, UIButton button)
{
    UIView.BeginAnimations (null, System.IntPtr.Zero);
    UIView.SetAnimationDelegate (this);
    UIView.SetAnimationCurve (UIViewAnimationCurve.EaseIn);
    UIView.SetAnimationDuration (0.5);
    button.Alpha = 1;
    UIView.CommitAnimations();
}

Answer 3

Isso é bem simples:

UIView button;

public void fadeButtonInAndOut()
{
    UIView.BeginAnimations("fadeOut");
    UIView.SetAnimationDelegate(this);
    UIView.SetAnimationDidStopSelector(new Selector("fadeOutDidFinish"));
    UIView.SetAnimationDuration(0.5f);
    button.Alpha = 0.0f;
    UIView.CommitAnimations();
}

[Export("fadeOutDidFinish")]
public void FadeOutDidFinish()
{
    UIView.BeginAnimations("fadeIn");
    UIView.SetAnimationDuration(0.5f);
    button.Alpha = 1.0f;
    UIView.CommitAnimations();
}