Iphone 控制随机生成元素的数量
我正在生成随机火球,但我的问题是它生成的火球数量太多 如何控制生成的火球数量Iphone 控制随机生成元素的数量,iphone,objective-c,random,Iphone,Objective C,Random,我正在生成随机火球,但我的问题是它生成的火球数量太多 如何控制生成的火球数量 - (void)onTimer { // build a view from our fire image UIImageView* fireView = [[UIImageView alloc] initWithImage:fireballs]; int startX = round(random() % 320); int endX = round(random() % 320)
- (void)onTimer
{
// build a view from our fire image
UIImageView* fireView = [[UIImageView alloc] initWithImage:fireballs];
int startX = round(random() % 320);
int endX = round(random() % 320);
double scale = 1 / round(random() % 100) + 1.0;
double speed = 1 / round(random() % 100) + 1.0;
fireView.frame = CGRectMake(startX, -100.0, 25.0 * scale, 25.0 * scale);
[self.view addSubview:fireView];
[UIView beginAnimations:nil context:fireView];
[UIView setAnimationDuration:5 * speed];
fireView.frame = CGRectMake(endX, 500.0, 25.0 * scale, 25.0 * scale);
[UIView setAnimationDidStopSelector:@selector(onAnimationComplete:finished:context:)];
[UIView setAnimationDelegate:self];
[UIView commitAnimations];
}
您可能需要调整启动计时器的频率。下面是一个示例,只需更改代码,其中“2.0”如下所示:
[NSTimer scheduledTimerWithTimeInterval:2.0
target:self
selector:@selector(targetMethod:)
userInfo:nil
repeats:NO];
它开始工作了!!我已将时间间隔设置为1.0,并重复:是。结果我得到了从屏幕顶部落下的几个火球,这就是我想要的!!谢谢