iOS 轉盤抽獎游戲(原生)

轉盤抽獎游戲在一般的app中都會有，應該算是一種吸引用戶的一種手段。在項目中集成轉盤抽獎游戲，大都采用h5的方式來實現，但是由於項目需求，需要在app中使用原生來實現轉盤抽獎。實現原理也很簡單，中間的一個圖片姑且把它叫做轉盤好了，當用戶點擊抽獎的時候，跟服務器做一次請求，拿到當前用戶即將獲得的獎品，根據獎品的位置，讓轉盤旋轉對應的時間，和對應的圈數，最后定位到抽獎的位置，轉盤結束轉動，彈窗讓用戶知曉自己的中獎情況。
好了，廢話說到這里，直接上效果圖：

核心代碼：

#define perSection    M_PI*2/8

-(void)animationWithSelectonIndex:(NSInteger)index{
    
    [self backToStartPosition];
    self.startButton.enabled = NO;
    self.needleImgView.image = [UIImage imageNamed:@"lottery_start_needle_noenable"];
    self.textImgView.image = [UIImage imageNamed:@"lottery_state_zhong"];
    CABasicAnimation *layer = [CABasicAnimation animationWithKeyPath:@"transform.rotation"];
    
    //先轉4圈 再選區 順時針(所以這里需要用360-對應的角度) 逆時針不需要
    layer.toValue = @((M_PI*2 - (perSection*index +perSection*0.5)) + M_PI*2*4);
    layer.duration = 4;
    layer.removedOnCompletion = NO;
    layer.fillMode = kCAFillModeForwards;
    layer.timingFunction = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseOut];
    layer.delegate = self;
    
    [self.gameBgView.layer addAnimation:layer forKey:nil];
}

-(void)backToStartPosition{
    CABasicAnimation *layer = [CABasicAnimation animationWithKeyPath:@"transform.rotation"];
    layer.toValue = @(0);
    layer.duration = 0.001;
    layer.removedOnCompletion = NO;
    layer.fillMode = kCAFillModeForwards;
    [self.gameBgView.layer addAnimation:layer forKey:nil];
}

#pragma mark - CAAnimationDelegate
- (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag {
    
    //設置指針返回初始位置
    self.startButton.enabled = YES;
    self.needleImgView.image = [UIImage imageNamed:@"lottery_start_needle_enable"];
    self.textImgView.image = [UIImage imageNamed:@"lottery_state_start"];
    if (self.rotaryEndTurnBlock) {
        self.rotaryEndTurnBlock();
    }
}

更多源碼請參考demo: https://github.com/qqcc1388/TYRotaryDemo
轉載請標注來源：https://www.cnblogs.com/qqcc1388/p/9121877.html