animateWithDuration:动画:阻止主线程？

dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{
    // 在后台线程上创建和执行动画
    [UIView animateWithDuration:0.3 animations:^{
        // 动画代码
    }];
});

CALayer *layer = self.view.layer;
CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"position"];
animation.duration = 0.3;
animation.fromValue = @(layer.position.x);
animation.toValue = @(layer.position.x + 100);
[layer addAnimation:animation forKey:@"position"];

// 在动画完成后手动移除动画
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.3 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
    [layer removeAnimationForKey:@"position"];
});