ios让textview支持特殊标签点击响应（@标签、#标签）

2）扩展UITextView：UITextFieldExtension.swift

import UIKit
 
extension UITextView {
    
    /**
     转换特殊符号标签字段
     */
    func resolveHashTags(){
        let nsText:NSString = self.text
        // 使用默认设置的字体样式
        let attrs = [NSFontAttributeName : self.font!]
        let attrString = NSMutableAttributedString(string: nsText as String,
                                                   attributes:attrs)
        
        //用来记录遍历字符串的索引位置
        var bookmark = 0
        //用于拆分的特殊符号
        let charactersSet = NSCharacterSet(charactersInString: "@#")
        
        //先将字符串按空格和分隔符拆分
        let sentences:[NSString] = self.text.componentsSeparatedByCharactersInSet(
            NSCharacterSet.whitespaceAndNewlineCharacterSet())
        
        for sentence in sentences {
            //如果是url链接则跳过
            if !verifyUrl(sentence as String) {
                //再按特殊符号拆分
                let words:[NSString] = sentence.componentsSeparatedByCharactersInSet(
                    charactersSet)
                var bookmark2 = bookmark
                for i in 0..                     let word = words[i]
                    let keyword = chopOffNonAlphaNumericCharacters(word as String)
                    if keyword != "" && i>0{
                        //使用自定义的scheme来表示各种特殊链接，比如：mention:hangge
                        //使得这些字段会变蓝色且可点击
                        
                        //匹配的范围
                        let remainingRangeLength = min((nsText.length - bookmark2 + 1),
                                                       word.length+2)
                        let remainingRange = NSRange(location: bookmark2-1,
                                                     length: remainingRangeLength)
                        print(keyword, bookmark2, remainingRangeLength)
                        
                        //匹配@某人
                        var matchRange = nsText.rangeOfString("@\(keyword)",
                                                options: .LiteralSearch,
                                                range:remainingRange)
                        attrString.addAttribute(NSLinkAttributeName,
                                                value: "mention:\(keyword)",
                                                range: matchRange)
                        
                        //匹配#话题#
                        matchRange = nsText.rangeOfString("#\(keyword)#",
                                    options: .LiteralSearch,
                                    range:remainingRange)
                        attrString.addAttribute(NSLinkAttributeName,
                                                value: "hash:\(keyword)",
                                                range: matchRange)
                    }
                    //移动坐标索引记录
                    bookmark2 += word.length + 1
                }
            }
            
            //移动坐标索引记录
            bookmark += sentence.length + 1
        }
        
        print(nsText.length,bookmark)
        
        //最终赋值
        self.attributedText = attrString
    }
    
    /**
     验证URL格式是否正确
     */
    private func verifyUrl(str:String) -> Bool {
        // 创建一个正则表达式对象
        do {
            let dataDetector = try NSDataDetector(types:
                NSTextCheckingTypes(NSTextCheckingType.Link.rawValue))
            // 匹配字符串，返回结果集
            let res = dataDetector.matchesInString(str,
                            options: NSMatchingOptions(rawValue: 0),
                            range: NSMakeRange(0, str.characters.count))
            // 判断结果(完全匹配)
            if res.count == 1  && res[0].range.location == 0
                && res[0].range.length == str.characters.count {
                return true
            }
        }
        catch {
            print(error)
        }
        return false
    }
    
    /**
     过滤部多余的非数字和字符的部分
     比如：@hangge.123 -> @hangge
     */
    func chopOffNonAlphaNumericCharacters(text:String) -> String {
        let nonAlphaNumericCharacters = NSCharacterSet
            .alphanumericCharacterSet().invertedSet
        let characterArray = text
            .componentsSeparatedByCharactersInSet(nonAlphaNumericCharacters)
        return characterArray[0]
    }
}

（3）测试页面代码：

import UIKit
 
class ViewController: UIViewController, UITextViewDelegate {
 
    //展示文本框
    @IBOutlet weak var displayTextView: UITextView!
    //编辑文本框
    @IBOutlet weak var editTextView: UITextView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        //设置展示文本框的代理
        displayTextView.delegate = self
    }
 
    //发送消息
    @IBAction func setMessage(sender: AnyObject) {
        //设置展示文本框的内容
        displayTextView.text = editTextView.text
        //对内容中的特殊标签字段做处理
        displayTextView.resolveHashTags()
        //清空输入框内容
        editTextView.text = ""
    }
    
    //展示文本框链接点击响应
    func textView(textView: UITextView, shouldInteractWithURL URL: NSURL,
                  inRange characterRange: NSRange) -> Bool {
        //判断URL scheme
        switch URL.scheme {
        case "hash" :
            showAlert("hash", payload:
                URL.resourceSpecifier.stringByRemovingPercentEncoding!)
        case "mention" :
            showAlert("mention", payload:
                URL.resourceSpecifier.stringByRemovingPercentEncoding!)
        default:
            print("这个是普通的url链接")
        }
        
        return true
    }
    
    //显示消息
    func showAlert(tagType:String, payload:String){
        let alertController = UIAlertController(title: "检测到\(tagType)标签",
            message: payload, preferredStyle: .Alert)
        let cancelAction = UIAlertAction(title: "确定", style: .Cancel, handler: nil)
        alertController.addAction(cancelAction)
        self.presentViewController(alertController, animated: true, completion: nil)
    }
    
    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
    }
}

原文出自：www.hangge.com