iOS 开发 富文本详解之TextKit详解

textkit结构

textkit使用步骤

#mark - 1. 自定义label  --class czlabel: uilabel---四个属性
//1.属性文本存储
private lazy var textstorage = nstextstorage()
//2.负责文本字形布局对象
private lazy var layoutmanager = nslayoutmanager()
//3.设定文本绘制的范围
private lazy var textcontainer = nstextcontainer()
//4.属性数组,保存匹配的范围
private lazy var linkranges = [nsrange]()

#mark - 2. 重新init方法-- override init(frame: cgrect) {}
//0.开启用户交互
userinteractionenabled = true
//1.textstorage接管label的属性
if let attributedtext = attributedtext {}
//2.设置对象关系
textstorage.addlayoutmanager(layoutmanager)
layoutmanager.addtextcontainer(textcontainer)

#mark - 3. 外界给label的text属性赋值  label.text = @"@好友,#健康#,....."
//重写属性的text方法--一旦label里的内容发生变化,就可以让textstorage相应变化
//1.段落处理--1.范围  2.属性  3.段落样式
let attrstringm = addlinebreak(attributedtext!)
//2.正则匹配--1.清空原有  2.匹配范围  3.创建正则  4.匹配  5.遍历匹配结果,添加到属性数组
regexlinkranges(attrstringm)
//3.连接颜色设置---1.范围  2.属性  3.添加颜色  4.遍历属性数组,改变颜色
addlinkattribute(attrstringm)
//4.添加到textstorage
textstorage.setattributedstring(attrstringm)
//5.重新绘制
setneedsdisplay()

#mark - 4. textstorage字形和属性发生变化时,通知nslayoutmanager重新布局文本
//mark:3.设置布局--制定文本绘制区域
override func layoutsubviews() {
    super.layoutsubviews()
    //制定文本绘制区域
    textcontainer.size = bounds.size
}

#mark - 5. 绘制textstorage的文本内容--不能调用super
override func drawtextinrect(rect: cgrect) {
    let range = nsmakerange(0, textstorage.length)
    //glyphs--字形---cgpoint()从原点绘制,也就是右上角
    layoutmanager.drawglyphsforglyphrange(range, atpoint: cgpoint(x: 0,y: 0))
}

#mark - 6. 用户点击事件交互
//0.懒加载@ # url的匹配的正则法则 三个属性数组
三步法:1.正则表达式  2.创建正则  3.匹配  4.便利匹配结果,添加到属性数组
 //1.获取用户点击的位置
let location = touches.first?.locationinview(self)
//2.获取当前点中字符的索引
let index = layoutmanager.glyphindexforpoint(location, intextcontainer: textcontainer)
//3.判断index在哪个标记的range 范围上
for range in atrange ?? [] {
    if nslocationinrange(index, range) {
        let strsub = (textstorage.string as nsstring).substringwithrange(range)
        //进行结果处理
    }
}

swift使用

import uikit

class zylabel: uilabel {        //attributedtext富文本

    //mark:2.重写属性text方法,可以在viewcontroller里给文本赋值
    //一旦label里的内容发生变化,就可以让textstorage相应变化
    override var text:string? {
        didset {
            if attributedtext == nil {
                return
            }
            //换行处理属性
            let attrstringm = addlinebreak(attributedtext!)
            //换行后进行--正则匹配
            regexlinkranges(attrstringm)
            //换行后进行--连接颜色设置
            addlinkattribute(attrstringm)
            //添加到textstorage
            textstorage.setattributedstring(attrstringm)
            //重新绘制
            setneedsdisplay()
        }
    }

    ///mark: textkit的三个核心对象
    //属性文本存储
    private lazy var textstorage = nstextstorage()
    //负责文本字形布局对象
    private lazy var layoutmanager = nslayoutmanager()
    //设定文本绘制的范围
    private lazy var textcontainer = nstextcontainer()
    private lazy var linkranges = [nsrange]()

    //纯代码接管label
    override init(frame: cgrect) {
        super.init(frame: frame)
        //0.开启用户交互
        userinteractionenabled = true

        //1.textstorage接管label的属性
        if let attributedtext = attributedtext {        //如果原有文本设置了attribute
            textstorage.setattributedstring(attributedtext)
        }else if let text = text {      //如果原有文本没有设置attribute
            textstorage.setattributedstring(nsattributedstring(string: text))
        }else {     //如果原有文本为nil
            textstorage.setattributedstring(nsattributedstring(string: ""))
        }

        //2.设置对象关系
        textstorage.addlayoutmanager(layoutmanager)
        layoutmanager.addtextcontainer(textcontainer)
    }
    //mark:1.xib接管label
    required init?(coder adecoder: nscoder) {
        super.init(coder: adecoder)
        //0.开启用户交互
        userinteractionenabled = true

        //1.准备文本内容---textstorage接管label的内容
        if let attributedtext = attributedtext {        //如果原有文本有attribute属性
            textstorage.setattributedstring(attributedtext)
        }else if let text = text {      //如果原有文本没有attribute属性
            textstorage.setattributedstring(nsattributedstring(string: text))
        }else {     //如果原有文本属性为nil
            textstorage.setattributedstring(nsattributedstring(string: ""))
        }

        //2.设置对象关系
        textstorage.addlayoutmanager(layoutmanager)
        layoutmanager.addtextcontainer(textcontainer)
    }

    /// mark:2.1.段落样式处理
    private func addlinebreak(attrstring: nsattributedstring) -> nsmutableattributedstring {
        let attrstringm = nsmutableattributedstring(attributedstring: attrstring)
        if attrstringm.length == 0 {
            return attrstringm
        }
        //从(0,0)点开始,也就是从text的第一个字符开始
        var range = nsrange(location: 0, length: 0)
        var attributes = attrstringm.attributesatindex(0, effectiverange: &range)
        var paragraphstyle = attributes[nsparagraphstyleattributename] as? nsmutableparagraphstyle

        //设置段落样式--以字符分割,不以单词分割
        if paragraphstyle != nil {
            //bywordwrapping//按照单词分割换行，保证换行时的单词完整。
            //bycharwrapping按照字母换行，可能会在换行时将某个单词拆分到两行
            paragraphstyle!.linebreakmode = nslinebreakmode.bycharwrapping
        } else {
            // ios 8.0 不能直接获取段落的样式
            paragraphstyle = nsmutableparagraphstyle()
            paragraphstyle!.linebreakmode = nslinebreakmode.bycharwrapping
            attributes[nsparagraphstyleattributename] = paragraphstyle
            attrstringm.setattributes(attributes, range: range)
        }
        return attrstringm
    }
    /// mark:2.2.连接的attribute的颜色设置
    private func addlinkattribute(attrstringm: nsmutableattributedstring) {
        if attrstringm.length == 0 {
            return
        }
        var range = nsrange(location: 0, length: 0)
        var attributes = attrstringm.attributesatindex(0, effectiverange:  &range)
        attrstringm.addattributes(attributes, range: range)
        attributes[nsforegroundcolorattributename] = uicolor.bluecolor()
        for range in linkranges {
            attrstringm.setattributes(attributes, range: range)
        }
    }
    /// mark:2.3.正则法则--匹配所有连接颜色:url,#话题#,@好友---放到一个数组里
    private let patterns = ["((http[s]{0,1}|ftp)://[a-za-z0-9\\.\\-]+\\.([a-za-z]{2,4})(:\\d+)?(/[a-za-z0-9\\.\\-~!@#$%^&*+?:[a-za-z0-9]{3}_/=<>]*)?)|(www.[a-za-z0-9\\.\\-]+\\.([a-za-z]{2,4})(:\\d+)?(/[a-za-z0-9\\.\\-~!@#$%^&*+?:_/=<>]*)?)", "#.*?#", "@[\\u4e00-\\u9fa5a-za-z0-9_-]*"]
    private func regexlinkranges(attrstring: nsattributedstring) {
        //存储所有的匹配结果前,将原来的清空
        linkranges.removeall()
        //正则匹配范围--整个label
        let regexrange = nsrange(location: 0, length: attrstring.string.characters.count)
        for pattern in patterns {
            //创建正则
            let regex = try! nsregularexpression(pattern: pattern, options: .dotmatcheslineseparators)
            //匹配
            let results = regex.matchesinstring(attrstring.string, options:nsmatchingoptions(rawvalue: 0) , range: regexrange)
            for range in results {      //每一种正则法则可能匹配到多个符合要求的对象如@张三  @李四 匹配到两个,结果是个数组
                linkranges.append(range.rangeatindex(0))
            }
        }
    }

    //mark:3.设置布局--制定文本绘制区域
    override func layoutsubviews() {
        super.layoutsubviews()
        //制定文本绘制区域
        textcontainer.size = bounds.size
    }

    //mark:4.绘制textstorage的文本内容--不能调用super
    override func drawtextinrect(rect: cgrect) {
        let range = nsmakerange(0, textstorage.length)
        //glyphs--字形---cgpoint()从原点绘制,也就是右上角
        layoutmanager.drawglyphsforglyphrange(range, atpoint: cgpoint(x: 0,y: 0))
    }

    //mark:5.用户点击事件交互--处理不同匹配内容天转到不同界面
    override func touchesbegan(touches: set, withevent event: uievent?) {
        //1.获取用户点击的位置--let location: cgpoint?
        guard let location = touches.first?.locationinview(self) else {
            return
        }

        //获取当前点中字符的索引
        let index = layoutmanager.glyphindexforpoint(location, intextcontainer: textcontainer)

        //判断index在哪个标记的range 范围上
        for range in atrange ?? [] {
            if nslocationinrange(index, range) {
                let strsub = (textstorage.string as nsstring).substringwithrange(range)
                print(strsub)
            }
        }
        for range in jingrange ?? [] {
            if nslocationinrange(index, range) {
                let strsub = (textstorage.string as nsstring).substringwithrange(range)
                print(strsub)
            }
        }
        for range in urlrange ?? [] {
            if nslocationinrange(index, range) {
                let strsub = (textstorage.string as nsstring).substringwithrange(range)
                nsnotificationcenter.defaultcenter().postnotificationname("webview", object: self, userinfo: ["urlstring":strsub])
            }
        }
    }
}

//mark: 正则表达式处理结果
extension zylabel {

    //返回textstorage中的@肝健康公益 的range数组
    var atrange:[nsrange]? {
        //正则表达式--@好友
        let pattern = "@[\u{4e00}-\u{9fa5}]{0,}"
        guard let regx = try? nsregularexpression(pattern: pattern, options: []) else {
            return nil
        }
        //多重匹配--//let matchs: [nstextcheckingresult]
        let matchs = regx.matchesinstring(textstorage.string, options: [], range: nsrange(location: 0,length: textstorage.length))
        //遍历数组
        var ranges = [nsrange]()
        for match in matchs {
            ranges.append(match.rangeatindex(0))
        }
        return ranges
    }

    //返回textstorage中的话题## 的range数组
    var jingrange:[nsrange]? {
        //正则表达式
        let pattern = "#[\u{4e00}-\u{9fa5}]{0,}#"
        guard let regx = try? nsregularexpression(pattern: pattern, options: []) else {
            return nil
        }
        //多重匹配--//let matchs: [nstextcheckingresult]
        let matchs = regx.matchesinstring(textstorage.string, options: [], range: nsrange(location: 0,length: textstorage.length))
        //遍历数组
        var ranges = [nsrange]()
        for match in matchs {
            ranges.append(match.rangeatindex(0))
        }
        return ranges
    }
    //返回textstorage中的url网址的range数组
    var urlrange:[nsrange]? {
        //正则表达式
        let pattern = "((http[s]{0,1}|ftp)://[a-za-z0-9\\.\\-]+\\.([a-za-z]{2,4})(:\\d+)?(/[a-za-z0-9\\.\\-~!@#$%^&*+?:[a-za-z0-9_/=<>]]*)?)|(www.[a-za-z0-9\\.\\-]+\\.([a-za-z]{2,4})(:\\d+)?(/[a-za-z0-9\\.\\-~!@#$%^&*+?:_/=<>]*)?)"
        guard let regx = try? nsregularexpression(pattern: pattern, options: []) else {
            return nil
        }
        //多重匹配--//let matchs: [nstextcheckingresult]
        let matchs = regx.matchesinstring(textstorage.string, options: [], range: nsrange(location: 0,length: textstorage.length))
        //遍历数组
        var ranges = [nsrange]()
        for match in matchs {
            ranges.append(match.rangeatindex(0))
        }
        return ranges
    }
}