iPhone怎么做指定路径的动画
之前做动画一直用这种方法
[UIView beginAnimations:@"animation" context:NULL]; [UIView setAnimationDuration:0.5f]; // 新位置 [UIView commitAnimations];
但是解决不了View需要转向的问题。
我现在需要让这个动画过程中，View有一个抖动的效果，这个实现不了，除非我用延迟，做两次动画，感觉这样很恶心。有没有什么办法是可以指定路径做动画的
燃烧的2B
11 years, 2 months ago
Answers
用Core Animation，可以指定动画路径。
下面例子实现一个物体下落再弹起的动画
[CATransaction begin];
[CATransaction setValue:[NSNumber numberWithFloat:ANIMATION_DURATION] forKey:kCATransactionAnimationDuration];
CAKeyframeAnimation *positionAnimation = [CAKeyframeAnimation animationWithKeyPath:@"position"];
CGMutablePathRef positionPath = CGPathCreateMutable();
CGPathMoveToPoint(positionPath, NULL, [theView layer].position.x, [theView layer].position.y);
CGPathAddQuadCurveToPoint(positionPath, NULL, [theView layer].position.x, - [theView layer].position.y, [theView layer].position.x, [theView layer].position.y);
CGPathAddQuadCurveToPoint(positionPath, NULL, [theView layer].position.x, - [theView layer].position.y * 1.5, [theView layer].position.x, [theView layer].position.y);
CGPathAddQuadCurveToPoint(positionPath, NULL, [theView layer].position.x, - [theView layer].position.y * 1.25, [theView layer].position.x, [theView layer].position.y);
positionAnimation.path = positionPath;
positionAnimation.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseIn];
[[theView layer] addAnimation:positionAnimation forKey:@"positionAnimation"];
CGPathRelease(positionPath);
[CATransaction commit];
当然，在
[CATransaction begin]; ... [CATransaction commit];
代码块中，你可以对一个或多个视图同时添加多个动画效果(如改变其颜色、大小等)，来实现更为复杂的动画
菊部地区有血
answered 11 years, 2 months ago
