【已解决】iOS11中导航栏上图标按钮被放大

iOS11中，导航栏上有个图标被放大了：

ios11 navigationbar item scale

ios11 navigationbar item transform

【总结】

iOS11+Xcode9中，navi bar上的barButtonItem的布局是用autolayout而不是frames

此处由于图片本身比较大，而button的大小比较小，所以autolayout后，图片被stretch撑大了

解决办法是：给button加上对应的宽高约束

代码：

extension UIView {

func applyNavBarConstraints(size: CGSize) {

let widthConstraint = self.widthAnchor.constraint(equalToConstant: size.width)

let heightConstraint = self.heightAnchor.constraint(equalToConstant: size.height)

heightConstraint.isActive = true

widthConstraint.isActive = true

}

let filterBtnSize = CGSize(width: 25, height: 25)

let fileBtn = UIButton(frame: CGRect(x: 0, y: 0, width: filterBtnSize.width, height: filterBtnSize.height))

fileBtn.addTarget(self, action: #selector(self.showReportFilterVC(sender:)), for: .touchUpInside)

fileBtn.setImage(NaviHtmlFilterImage, for: .normal)

fileBtn.applyNavBarConstraints(size: filterBtnSize)

let fileBarBtn = UIBarButtonItem(customView: fileBtn)

self.navigationItem.setRightBarButton(fileBarBtn, animated: true)

效果：