《30天精通iPhone手机编程》－Day29－跳跃动作

        人物的跳跃动作由几个图片连续播放组成

        

//跳跃动作- (IBAction)jump:(id)sender{//强调人物在落地之前不能再多跳一下if(RYU.center.y > 216){//定义图像的关键帧动画属性值RYU.animationImages = [NSArray arrayWithObjects:    [UIImage imageNamed:@"jump1.png"],   [UIImage imageNamed:@"jump2.png"],   [UIImage imageNamed:@"jump2.png"],   [UIImage imageNamed:@"jump1.png"],   nil];//持续时间RYU.animationDuration = 0.2;RYU.animationRepeatCount = 1;[RYU startAnimating];[UIImageView beginAnimations:@"jump" context:RYU];[UIImageView setAnimationDuration:0.2];RYU.center=CGPointMake(RYU.center.x, RYU.center.y-50);    RYU.center=CGPointMake(RYU.center.x, RYU.center.y+50);[UIImageView commitAnimations];        }}