//按钮出现时的动画效果
+ (void)buttonAnimation:(UIButton *)sender {
CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath:@"transform"];
CATransform3D scale1 = CATransform3DMakeScale(0.5, 0.5, 1);
CATransform3D scale2 = CATransform3DMakeScale(1.2, 1.2, 1);
CATransform3D scale3 = CATransform3DMakeScale(0.9, 0.9, 1);
CATransform3D scale4 = CATransform3DMakeScale(1.0, 1.0, 1);
NSArray *frameValues = [NSArray arrayWithObjects:
[NSValue valueWithCATransform3D:scale1],
[NSValue valueWithCATransform3D:scale2],
[NSValue valueWithCATransform3D:scale3],
[NSValue valueWithCATransform3D:scale4],
nil];
[animation setValues:frameValues];
NSArray *frameTimes = [NSArray arrayWithObjects:
[NSNumber numberWithFloat:0.0],
[NSNumber numberWithFloat:0.5],
[NSNumber numberWithFloat:0.9],
[NSNumber numberWithFloat:1.0],
nil];
[animation setKeyTimes:frameTimes];
animation.fillMode = kCAFillModeForwards;
animation.duration = 0.3f;
[sender.layer addAnimation:animation forKey:@"DSPopUpAnimation"];
}