Swift-UIKit-UILabel

1.描述

class UILabel : UIView

UILabel继承自UIView

苹果官方文档:

A view that displays one or more lines of informational text.(是一个描述一行或者多行文本信息的视图)

UILabel支持展示属性字符串(attributed strings).并且支持多行展示,如果设置好约束,还可以进行高度的自适应.

UILabel大多通过NSString赋值给text或者NSAttributeString给attributeText来展示内容.

2.代码实例

    let myLabel = UILabel()
    view.addSubview(myLabel)
    myLabel.frame = CGRect(x: 100, y: 100, width: 100, height: 100)
    myLabel.backgroundColor = UIColor.red
    myLabel.text = "Hello UILabel"
    //设置字体样式
    myLabel.font = UIFont.systemFont(ofSize: 15)
    //右对齐
    myLabel.textAlignment = NSTextAlignment.right
    //头部截取
    myLabel.lineBreakMode = NSLineBreakMode.byTruncatingHead
    //不可编辑状态--会字体变灰
    myLabel.isEnabled = false;
    
    //继承自UIView,设置是否可以相应用户交互,默认值为false
    myLabel.isUserInteractionEnabled = true;

    //preferredMaxLayoutWidth
    myLabel.text = "Hello UILabel,Hello UILabel,Hello UILabel,Hello UILabel"
    myLabel.numberOfLines = 0;
    myLabel.translatesAutoresizingMaskIntoConstraints = false
    let constraintArrayH = NSLayoutConstraint.constraints(withVisualFormat: "H:|-100-[customLabel]", options: NSLayoutConstraint.FormatOptions(), metrics: nil, views: ["customLabel":myLabel])
    let constraintArrayV = NSLayoutConstraint.constraints(withVisualFormat: "V:|-100-[customLabel]", options: NSLayoutConstraint.FormatOptions(), metrics: nil, views: ["customLabel":myLabel])
    self.view.addConstraints(constraintArrayH)
    self.view.addConstraints(constraintArrayV)
    //用于约束层面控制字符串宽的的属性
    myLabel.preferredMaxLayoutWidth = 100

    //多属性字符串作为展示内容
    let aString: NSMutableAttributedString = NSMutableAttributedString.init(string: "Hello UILabel with NSAttributedString")
    let range = NSMakeRange(0, 5)
    aString.setAttributes([NSAttributedString.Key.foregroundColor:UIColor.green],range:range)
    myLabel.attributedText = aString;
    print("Hello UILabel")

• 工程下载地址:待补充

3.总结

UILable是常用的用于展示文本信息的控件,详情请参考苹果官方文档:UIKit->UILabel