swift封装一个继承UILabel的红色小圆圈用来显示消息的个数

来源：互联网发布：智能合约知乎编辑：程序博客网时间：2024/05/22 04:37

在app中往往会需要去显示一些通知的信息的个数，往往是在图标上面加一个红色的小圆圈，然后在上面动态的显示在消息的个数，就像微信中提示信息的个数一样。效果图如下：

现将如图红色圆圈的中的数字显示样式封装如下：

import UIKitclass Info: UILabel {  var defaultInsets = CGSize(width: 2, height: 2)  var actualInsets = CGSize()    convenience init() {    self.init(frame: CGRect())  }    override init(frame: CGRect) {    super.init(frame: frame)        setup()  }    required init?(coder aDecoder: NSCoder) {    super.init(coder: aDecoder)        setup()  }    private func setup() {    translatesAutoresizingMaskIntoConstraints = false        layer.backgroundColor = UIColor.redColor().CGColor    textColor = UIColor.whiteColor()        // Shadow    layer.shadowOpacity = 0.5    layer.shadowOffset = CGSize(width: 0, height: 0)    layer.shadowRadius = 0.5    layer.shadowColor = UIColor.blackColor().CGColor        self.textAlignment = NSTextAlignment.Center  }    // Add custom insets  // --------------------  override func textRectForBounds(bounds: CGRect, limitedToNumberOfLines numberOfLines: Int) -> CGRect {    let rect = super.textRectForBounds(bounds, limitedToNumberOfLines: numberOfLines)        actualInsets = defaultInsets    let rectWithDefaultInsets = CGRectInset(rect, -actualInsets.width, -actualInsets.height)        // If width is less than height    // Adjust the width insets to make it look round    if rectWithDefaultInsets.width < rectWithDefaultInsets.height {      actualInsets.width = (rectWithDefaultInsets.height - rect.width) / 2    }        return CGRectInset(rect, -actualInsets.width, -actualInsets.height)  }    override func drawTextInRect(rect: CGRect) {        layer.cornerRadius = rect.height / 2        let insets = UIEdgeInsets(      top: actualInsets.height,      left: actualInsets.width,      bottom: actualInsets.height,      right: actualInsets.width)        let rectWithoutInsets = UIEdgeInsetsInsetRect(rect, insets)        super.drawTextInRect(rectWithoutInsets)  }}

调用使用的代码如下：

例如：

var noticeNum:Info!noticeNum = Info(frame: CGRect(x:100, y:100, width : 25, height : 25))noticeNum.text = "31"self.View.addSubview(noticeNum)

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