我如何使用MonoTouch为UIButton Alpha属性设置动画
问题描述:
我有一个简单的带有Alpha属性的UIButton,我想从1.0f动画到0.0f,然后回到1.0f。这基本上是对TouchDown的回应。我如何使用MonoTouch为UIButton Alpha属性设置动画
此外,有什么特别的我需要做的,如果我打来的例程不在主线程(在ThreadPool上调用的异步委托)?
我应该使用CAAnimation吗?
谢谢!
答
除非有人管了一个单声道的方式来做到这一点,我说的使用:
- (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];
}
答
这是非常简单的:
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();
}
答
谢谢你的iPhone后置代号。
第二个答案是使用全局变量并跳过回调的参数。 这是我今天根据第一个答案想出来的。
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();
}
很好的回答;非常容易移植到单声道 – rpetrich 2009-09-25 04:09:38