功能
点击大转盘旋转后固定到某个自己可以确定的位置
结构
转盘，开始按钮，指针
技术
CADisplayLink不停重绘，CGAffineTransform旋转，简单数学公式
核心代码
1.使用CADisplayLink不停重绘旋转底盘
// 开始转动(一直不停的转动)
- (void)startRotate
{ CADisplayLink* link = [CADisplayLink displayLinkWithTarget:self selector:@selector(Rotate)];
[link addToRunLoop:[NSRunLoop mainRunLoop] forMode:NSDefaultRunLoopMode];
self.link = link;
} //
- (void)Rotate {
//每次旋转6°
self.rotateWheel.transform = CGAffineTransformRotate(self.rotateWheel.transform, M_PI * / / );
}
2.点击开始执行旋转动画,
if (![self.rotateWheel.layer animationForKey:@"zhuandong"]) {
CABasicAnimation* animation = [[CABasicAnimation alloc] init];
animation.keyPath = @"transform.rotation";
animation.toValue = @( * M_PI * - M_PI*/*(-self.numberIndex));
animation.duration = ;
animation.removedOnCompletion = NO;
animation.fillMode = kCAFillModeForwards;
[self.rotateWheel.layer addAnimation:animation forKey:@"zhuandong"];
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(animation.duration * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
self.rotateWheel.transform = CGAffineTransformMakeRotation(M_PI*/*(-self.numberIndex));
self.link.paused = YES;
[self.rotateWheel.layer removeAnimationForKey:@"zhuandong"];
UIAlertView* alert = [[UIAlertView alloc] initWithTitle:@"温馨提示" message:@"恭喜你!被骗了!!!" delegate:self cancelButtonTitle:@"确定" otherButtonTitles:nil, nil];
[alert show];
if (_delegate && [_delegate respondsToSelector:@selector(LuckyDrawViewDidFinishWidthIndex:)]) {
[_delegate LuckyDrawViewDidFinishWidthIndex:self.numberIndex];
}
self.numberIndex = ;
});
}3.其间控制转盘最后停留的位置用一个变量控制就行了
@property (nonatomic,assign)NSInteger numberIndex;