我有我转换（旋转）的UIProgressView，所以它是垂直的，我的问题是底部约束因视图旋转而无法正确显示，UIView和UIProgressView的底部并没有完全对齐，我也尝试过更改锚点，底部也无法对齐。
- (void)viewDidLoad {
[super viewDidLoad];
[self initFlow];
self._wProgressView = [[UIProgressView alloc] init];
[self._middleRightView addSubview:self._wProgressView];
[self._wProgressView setProgress:0.7];
CGPoint newCenter = self._wProgressView.layer.anchorPoint;
newCenter.x = 0;
newCenter.y = 1;
[self._wProgressView.layer setAnchorPoint:newCenter];
self._wProgressView.transform = CGAffineTransformRotate(self._wProgressView.transform, -0.5 *M_PI);
// [self._wProgressView.centerXAnchor constraintEqualToAnchor:self._wProgressView.superview.centerXAnchor].active = YES;
self._wProgressView.translatesAutoresizingMaskIntoConstraints = NO;
[self._wProgressView.bottomAnchor constraintEqualToAnchor:self._wImageView.bottomAnchor].active = YES;
[self._wProgressView.widthAnchor constraintEqualToAnchor:self._wProgressView.superview.heightAnchor multiplier:0.5].active = YES;
[self._wProgressView.heightAnchor constraintEqualToAnchor:self._wProgressView.superview.widthAnchor constant:0.8].active = YES;
//= self._wProgressView.superview.centerXAnchor;
}