//创建UIImageView
self.imgViewLoading = [[UIImageView alloc]initWithImage:[UIImage imageNamed:@"ioading_50_1"]];
[_viewLoading addSubview:self.imgViewLoading];
[self.imgViewLoading mas_makeConstraints:^(MASConstraintMaker *make) {
make.size.mas_equalTo(CGSizeMake(150, 150));
make.centerX.equalTo(_viewLoading);
make.top.equalTo(_viewLoading.mas_top).with.offset(height + 10);
}];
//加载动画
CABasicAnimation *animation = [CABasicAnimation animation];
animation.keyPath = @"transform.rotation";
animation.duration = 1.0;
animation.repeatCount = INFINITY;
animation.byValue = @(M_PI * 2);
[self.imgViewLoading.layer addAnimation:animation forKey:nil];
//停止运动需要remove
[self.imgViewLoading.layer removeAllAnimations];
