swift中自定义Label的文字范围

某些时候，我们需要调整文字的显示范围（比如使用Label自定义提示语）已更美观的时候,最简单的方法就是继承UIlabel后重写UILable的相关方法；这里写swift的实现版本，OC的实现类似
首先我们需要一个新建的UIEdgeInsets属性，以及重新构造init方法

var edgesInset : UIEdgeInsets?
    
    override init(frame: CGRect) {
        super.init(frame: frame);
        self.edgesInset = UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10)
        
    }

    override func awakeFromNib() {
        super.awakeFromNib()
        self.edgesInset = UIEdgeInsets(top: 10, left: 10, bottom: 10, right: 10)
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    

接着重写他的rect范围

    override func textRect(forBounds bounds: CGRect, limitedToNumberOfLines numberOfLines: Int) -> CGRect {
        var rect = super.textRect(forBounds: UIEdgeInsetsInsetRect(bounds, self.edgesInset!), limitedToNumberOfLines: numberOfLines)
        rect.origin.x = rect.origin.x - (self.edgesInset?.left)!
        rect.origin.y = rect.origin.y - (self.edgesInset?.top)!
        rect.size.width = rect.size.width + (self.edgesInset?.left)! + (self.edgesInset?.right)!
        rect.size.height = rect.size.height + (self.edgesInset?.top)! + (self.edgesInset?.bottom)!

        return rect
        
    }

最后自然是重绘文字的显示范围

override func drawText(in rect: CGRect) {
        super.drawText(in: UIEdgeInsetsInsetRect(rect, self.edgesInset!))
    }

ok,这就搞定了，之所以重新定制Label的文字范围，是因为要写一个通用的提示，依托于snp就可以很轻易的实现，而不需要去引入第三方库