执行多个顺序UIView动画的最佳方式？
执行多个顺序UIView动画的最佳方式？
提问于 2010-10-03 18:52:08
我有一系列的8个UIView动画，这些动画在我的视图加载后立即发生。现在，我正在使用animationDidStop:finished:context委托方法来完成这项工作，一切都按预期进行。问题是我对每个动画都有一个新的方法。这些方法中的大多数代码都是重复的，只有动画持续时间和元素的实际位置发生了变化。
我试图创建一个方法，该方法将被调用，并让上下文保存适当更改UI所需的参数，但它似乎递归地调用自身，远远超过了我调用它的次数：
-(void)animationDidStop:(NSString *)animationID finished:(BOOL)finished context:(void *)context{
NSNumber *number = (NSNumber *)context;
int animationStep = [number intValue];
int nextAnimationStep = animationStep + 1;
NSNumber *nextAnimationStepNumber = [NSNumber numberWithInt:nextAnimationStep];
NSLog(@"Animation Step: %i", animationStep);
CGRect firstFrame = CGRectMake(self.feedsScroll.frame.size.width * 2, 0.0f, self.secondFeedView.view.frame.size.width, self.secondFeedView.view.frame.size.height);
CGRect thirdFrame = CGRectMake(self.feedsScroll.frame.size.width * 2, 0.0f, self.thirdFeedView.view.frame.size.width, self.thirdFeedView.view.frame.size.height);
[UIView beginAnimations:nil context:nextAnimationStepNumber];
[UIView setAnimationBeginsFromCurrentState:YES];
[UIView setAnimationCurve:UIViewAnimationCurveLinear];
[UIView setAnimationDelegate:self];
if (animationStep < 8)
[UIView setAnimationDidStopSelector:@selector(animationDidStop:finished:context:)];
NSLog(@"Beginning animations");
switch (animationStep) {
case 0:
[UIView setAnimationDuration:.3];
self.firstFeedView.view.center = CGPointMake(self.firstFeedView.view.center.x + 30, self.firstFeedView.view.center.y);
break;
case 1:
[UIView setAnimationDuration:.3];
self.firstFeedView.view.center = CGPointMake(self.firstFeedView.view.center.x - 30, self.firstFeedView.view.center.y);
break;
case 2:
[UIView setAnimationDuration:.3];
[self.secondFeedView.view setFrame:firstFrame];
break;
case 3:
[UIView setAnimationDuration:.3];
self.secondFeedView.view.center = CGPointMake(self.secondFeedView.view.center.x + 30, self.firstFeedView.view.center.y);
break;
case 4:
[UIView setAnimationDuration:.3];
self.secondFeedView.view.center = CGPointMake(self.secondFeedView.view.center.x - 30, self.firstFeedView.view.center.y);
break;
case 5:
NSLog(@"Animation step 6");
[UIView setAnimationDuration:.5];
self.firstFeedView.view.center = CGPointMake(self.firstFeedView.view.center.x - 230, self.firstFeedView.view.center.y);
self.secondFeedView.view.center = CGPointMake(self.secondFeedView.view.center.x - 230, self.firstFeedView.view.center.y);
break;
case 6:
[UIView setAnimationDuration:.5];
[self.thirdFeedView.view setFrame:thirdFrame];
break;
case 7:
[UIView setAnimationDuration:.3];
self.thirdFeedView.view.center = CGPointMake(self.thirdFeedView.view.center.x + 30, self.firstFeedView.view.center.y);
break;
case 8:
[UIView setAnimationDuration:.3];
self.thirdFeedView.view.center = CGPointMake(self.thirdFeedView.view.center.x - 30, self.thirdFeedView.view.center.y);
break;
default:
break;
}
[UIView commitAnimations];
}我知道这可能是一个幼稚的实现。我是iPhone开发的新手，正在寻找一些最佳实践应用于此。我是不是走错了路？
回答 4
Stack Overflow用户
发布于 2010-10-04 05:28:57
如果您愿意升级到iOS 4.0，新的基于块的动画方法可以使这种动画链接变得微不足道。例如：
[UIView animateWithDuration:1.0 animations:^{ view.position = CGPointMake(0.0f, 0.0f); } completion:^(BOOL finished){
[UIView animateWithDuration:0.2 animations:^{ view.alpha = 0.0; } completion:^(BOOL finished){
[view removeFromSuperview]; }];
}]将导致view在1秒的持续时间内动画为(0，0)，淡出0.2秒，然后从其超级视图中删除。这些动画将是连续的。
+animateWithDuration:animations:completion:类方法中的第一个块包含要立即设置动画的属性更改，第二个块是动画完成时要执行的操作。由于此回调可以包含另一个此类动画，因此您可以嵌套它们来创建任意的动画链。
Stack Overflow用户
发布于 2013-04-03 14:38:15
您可以使用块来实现此目的，并获得一个非常干净的结果。
NSMutableArray* animationBlocks = [NSMutableArray new];
typedef void(^animationBlock)(BOOL);
// getNextAnimation
// removes the first block in the queue and returns it
animationBlock (^getNextAnimation)() = ^{
animationBlock block = (animationBlock)[animationBlocks firstObject];
if (block){
[animationBlocks removeObjectAtIndex:0];
return block;
}else{
return ^(BOOL finished){};
}
};
//add a block to our queue
[animationBlocks addObject:^(BOOL finished){;
[UIView animateWithDuration:1.0 animations:^{
//...animation code...
} completion: getNextAnimation()];
}];
//add a block to our queue
[animationBlocks addObject:^(BOOL finished){;
[UIView animateWithDuration:1.0 animations:^{
//...animation code...
} completion: getNextAnimation()];
}];
//add a block to our queue
[animationBlocks addObject:^(BOOL finished){;
NSLog(@"Multi-step Animation Complete!");
}];
// execute the first block in the queue
getNextAnimation()(YES);摘自：http://xibxor.com/objective-c/uiview-animation-without-nested-hell/
Stack Overflow用户
发布于 2011-07-28 14:56:02
我们创建了一个组件，用于使用块(CPAnimationSequence on Github)以声明方式链接动画步骤。我们描述了in our iOS development blog的动机和基本原理。
它提供了可读性非常好的代码，如下所示：
[[CPAnimationSequence sequenceWithSteps:
[CPAnimationStep for:0.25 animate:^{ self.imageView.alpha = 0.0; }],
[CPAnimationStep for:0.25 animate:^{ self.headline.alpha = 0.0; }],
[CPAnimationStep for:0.25 animate:^{ self.content.alpha = 0.0; }],
[CPAnimationStep after:1.0 for:0.25 animate:^{ self.headline.alpha = 1.0; }],
[CPAnimationStep for:0.25 animate:^{ self.content.alpha = 1.0; }],
nil]
runAnimated:YES];页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/3849460
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