UIImageView 对齐

Question

我在 tableviewcell 中有一个 UIImageView，并将内容模式设置为 scaleAspectFill：

let imageSize = CGSize(width: 70, height: 70)
MenuImage.contentMode = .scaleAspectFill

if(self.reuseIdentifier == "cell1") {
    MenuImage.image = UIImage.imageWithIonicon(.Map, color: UIColor.white, iconSize: 70, imageSize: imageSize)
}
else if (self.reuseIdentifier == "cell2") {
    MenuImage.image = UIImage.imageWithIonicon(.iOSPerson, color: UIColor.white, iconSize: 70, imageSize: imageSize)

}
else if (self.reuseIdentifier == "cell3") {
    MenuImage.image = UIImage.imageWithIonicon(.iOSHelp, color: UIColor.white, iconSize: 70, imageSize: imageSize)
}

虽然这使图像非常适合单元格，但图像似乎与底部对齐。有没有办法让它在 UIImageView 中垂直居中（棕色背景只是为了检查图像视图的大小）

Answer 1

根据This，为了修复垂直对齐，您需要在“ionicons.swift”文件中更改此行：

attString.drawInRect(CGRect(x: (imageSize.width / 2) - boundingRect.size.width / 2, y: (imageSize.height / 2) - boundingRect.size.height / 2, width: imageSize.width, height: imageSize.height))

到

attString.drawInRect(CGRect(x: (imageSize.width / 2) - (boundingRect.size.width / 2), y: (imageSize.height / 2) - (iconSize / 2), width: imageSize.width, height: imageSize.height))

*Swift 3.0 版本，替换为：

attString.draw(in: CGRect(x: (imageSize.width / 2) - boundingRect.size.width / 2, y: (imageSize.height / 2) - boundingRect.size.height / 2, width: imageSize.width, height: imageSize.height))

与

attString.draw(in: CGRect(x: (imageSize.width / 2) - (boundingRect.size.width / 2), y: (imageSize.height / 2) - (iconSize / 2), width: imageSize.width, height: imageSize.height))

Answer 2

这是一个关于约束和锚点的例子：

self.addSubview(containerView)
containerView.addSubview(yourImageView)

containerView.bottomAnchor.constraintEqualToAnchor(self.bottomAnchor).active=true
containerView.leftAnchor.constraintEqualToAnchor(self.leftAnchor).active=true

yourImageView.topAnchor.constraintEqualToAnchor(containerView.topAnchor).active=true
yourImageView.leftAnchor.constraintEqualToAnchor(containerView.leftAnchor).active=true
yourImageView.widthAnchor.constraintEqualToConstant(70).active=true
yourImageView.heightAnchor.constraintEqualToConstant(70).active=true