1.描述

A scrollable, multiline text region.(一个多行的可滚动的文本区域)

class UITextView : UIScrollView

我们可以理解其为多行的UITextField,其特性基本与其相似所以这里不多加赘述.

2.代码示例

    let myTextView1 = UITextView()
    self.view.addSubview(myTextView1)
    myTextView1.backgroundColor = UIColor.lightGray
    myTextView1.translatesAutoresizingMaskIntoConstraints = false
//        let constrantArrayH =  NSLayoutConstraint.constraints(withVisualFormat: "H:|-100-[tv(200)]", options: NSLayoutConstraint.FormatOptions(), metrics: nil, views: ["tv" : myTextView1])
    
    let constrantArrayH =  NSLayoutConstraint.init(item: myTextView1, attribute: NSLayoutConstraint.Attribute.leading, relatedBy: NSLayoutConstraint.Relation.equal, toItem: self.view, attribute: NSLayoutConstraint.Attribute.leading, multiplier: 1, constant: 100)
    let constrantArrayH1 =  NSLayoutConstraint.init(item: myTextView1, attribute: NSLayoutConstraint.Attribute.width, relatedBy: NSLayoutConstraint.Relation.equal, toItem: nil, attribute: NSLayoutConstraint.Attribute.width, multiplier: 0, constant: 200)
    
    
    let constrantArrayW = NSLayoutConstraint.constraints(withVisualFormat: "V:|-100-[tv(200)]", options: NSLayoutConstraint.FormatOptions(), metrics: nil, views: ["tv" : myTextView1])
//        self.view.addConstraint(constrantArrayH)
//        self.view.addConstraint(constrantArrayH1)
    self.view.addConstraints([constrantArrayH,constrantArrayH1])
    self.view.addConstraints(constrantArrayW)
    

    
    
    let attributedString = NSMutableAttributedString.init(string: "富文本---内容")
    attributedString.addAttribute(NSAttributedString.Key.foregroundColor, value: UIColor.green, range: NSRange.init(location: 0, length: 2))
    attributedString.addAttributes([NSAttributedString.Key.font : UIFont.systemFont(ofSize: 20),NSAttributedString.Key.backgroundColor : UIColor.red], range: NSRange.init(location: 2, length: 1))
myTextView1.attributedText = attributedString

• 工程下载地址:

https://github.com/DeveloperZhang/SwiftStudyDemo

3.总结

UITextField是一个最基础常见的视图类,可以参考文档进行深入学习:UIKit->Views and Controls->UITextView