Vue+Less/Scss实现主题切换功能_vue皮肤颜色切换

前言：目前，在众多的后台管理系统中，换肤功能已是一个很常见的功能。用户可以根据自己的喜好，设置页面的主题，从而实现个性化定制。

目前，我所了解到的换肤方式，也是我目前所掌握的两种换肤方式，想同大家一起分享。

一、Less/Scss变量换肤

具体实现：

1、初始化vue项目

2、安装插件：

npm install style-resources-loader -D

npm install vue-cli-plugin-style-resources-loader -D

当然也要安装less、less-loader等插件，具体的安装配置，请自行google

3、新建theme.less文件用于全局样式配置。在src目录下新建theme文件夹，在这个文件夹下新建theme.less文件。具体如下：

/src/theme/theme.less
 
// 默认的主题颜色
@primaryColor: var(--primaryColor, #000);
@primaryTextColor: var(--primaryTextColor, green);
// 导出变量
:export {
  name: "less";
  primaryColor: @primaryColor;
  primaryTextColor: @primaryTextColor;
}

4、配置vue.config.js文件，实现全局使用变量实现换肤

const path = require("path");
module.exports = {
  pluginOptions: {
    "style-resources-loader": {
      preProcessor: "less",
      patterns: [
        // 这个是加上自己的路径,不能使用(如下:alias)中配置的别名路径
        path.resolve(__dirname, "./src/theme/theme.less"),
      ],
    },
  },
};

5、具体的使用：

<template>
  <div class="hello">
    <p>我是测试文字</p>
  </div>
</template>
 
<script>
export default {
  name: "HelloWorld",
};
</script>
<style scoped lang="less">
.hello {
  p {
    color: @primaryTextColor;
  }
}
</style>

备注：如果是用scss也基本同以上用法，只是scss的变量名用‘$’作为前缀，less使用@

至此，我们已经实现了静态更换皮肤，那如何实现动态换肤呢，最重要的就是以下的文件了。

我们可以多配置几种默认主题

6、在theme文件夹下新建model.js文件，用于存放默认主题

// 一套默认主题以及一套暗黑主题
// 一套默认主题以及一套暗黑主题
export const themes = {
  default: {
    primaryColor: `${74}, ${144},${226}`,
    primaryTextColor: `${74}, ${144},${226}`,
  },
  dark: {
    primaryColor: `${0},${0},${0}`,
    primaryTextColor: `${0},${0},${0}`,
  },
};

7、实现动态切换：

在/src/theme文件夹下新建theme.js文件，代码如下：

import { themes } from "./model";
// 修改页面中的样式变量值
const changeStyle = (obj) => {
  for (let key in obj) {
    document
      .getElementsByTagName("body")[0]
      .style.setProperty(`--${key}`, obj[key]);
  }
};
// 改变主题的方法
export const setTheme = (themeName) => {
  localStorage.setItem("theme", themeName); // 保存主题到本地，下次进入使用该主题
  const themeConfig = themes[themeName];
  // 如果有主题名称，那么则采用我们定义的主题
  if (themeConfig) {
    localStorage.setItem("primaryColor", themeConfig.primaryColor); // 保存主题色到本地
    localStorage.setItem("primaryTextColor", themeConfig.primaryTextColor); // 保存文字颜色到本地
    changeStyle(themeConfig); // 改变样式
  } else {
    let themeConfig = {
      primaryColor: localStorage.getItem("primaryColor"),
      primaryTextColor: localStorage.getItem("primaryTextColor"),
    };
    changeStyle(themeConfig);
  }
};

8、切换主题

this.setTheme('dark')

二、element-UI组件的换肤

1、一般elementUI主题色都有这样一个文件element-variables.scss：

/**
* I think element-ui's default theme color is too light for long-term use.
* So I modified the default color and you can modify it to your liking.
**/
 
/* theme color */
$--color-primary: #1890ff;
$--color-success: #13ce66;
$--color-warning: #ffba00;
$--color-danger: #ff4949;
// $--color-info: #1E1E1E;
 
$--button-font-weight: 400;
 
// $--color-text-regular: #1f2d3d;
 
$--border-color-light: #dfe4ed;
$--border-color-lighter: #e6ebf5;
 
$--table-border: 1px solid #dfe6ec;
 
/* icon font path, required */
$--font-path: "~element-ui/lib/theme-chalk/fonts";
 
@import "~element-ui/packages/theme-chalk/src/index";
 
// the :export directive is the magic sauce for webpack
// https://www.bluematador.com/blog/how-to-share-variables-between-js-and-sass
:export {
  theme: $--color-primary;
}

2、main.js中引用

import './styles/element-variables.scss'

3、在store文件夹下新建settings.js文件，用于页面基础设置

import variables from '@/styles/element-variables.scss'
const state = {
  theme: variables.theme
}
const mutations = {
  CHANGE_SETTING: (state, { key, value }) => {
    // eslint-disable-next-line no-prototype-builtins
    if (state.hasOwnProperty(key)) {
      state[key] = value
    }
  }
}
const actions = {
  changeSetting({ commit }, data) {
    commit('CHANGE_SETTING', data)
  }
}
export default {
  namespaced: true,
  state,
  mutations,
  actions
}

4、一般换肤都是需要有个颜色选择器，用于皮肤设置

在src目录下新建ThemePicker文件夹，新建index.vue文件。

<template>
  <el-color-picker
    v-model="theme"
    :predefine="['#409EFF', '#1890ff', '#304156','#212121','#11a983', '#13c2c2', '#6959CD', '#f5222d', ]"
    class="theme-picker"
    popper-class="theme-picker-dropdown"
  />
</template>
 
<script>
const version = require('element-ui/package.json').version // element-ui version from node_modules
const ORIGINAL_THEME = '#409EFF' // default color
 
export default {
  data() {
    return {
      chalk: '', // content of theme-chalk css
      theme: ''
    }
  },
  computed: {
    defaultTheme() {
      return this.$store.state.settings.theme
    }
  },
  watch: {
    defaultTheme: {
      handler: function(val, oldVal) {
        this.theme = val
      },
      immediate: true
    },
    async theme(val) {
      const oldVal = this.chalk ? this.theme : ORIGINAL_THEME
      if (typeof val !== 'string') return
      const themeCluster = this.getThemeCluster(val.replace('#', ''))
      const originalCluster = this.getThemeCluster(oldVal.replace('#', ''))
      console.log(themeCluster, originalCluster)
 
      const $message = this.$message({
        message: '  Compiling the theme',
        customClass: 'theme-message',
        type: 'success',
        duration: 0,
        iconClass: 'el-icon-loading'
      })
 
      const getHandler = (variable, id) => {
        return () => {
          const originalCluster = this.getThemeCluster(ORIGINAL_THEME.replace('#', ''))
          const newStyle = this.updateStyle(this[variable], originalCluster, themeCluster)
 
          let styleTag = document.getElementById(id)
          if (!styleTag) {
            styleTag = document.createElement('style')
            styleTag.setAttribute('id', id)
            document.head.appendChild(styleTag)
          }
          styleTag.innerText = newStyle
        }
      }
 
      if (!this.chalk) {
        const url = `https://unpkg.com/element-ui@${version}/lib/theme-chalk/index.css`
        await this.getCSSString(url, 'chalk')
      }
 
      const chalkHandler = getHandler('chalk', 'chalk-style')
 
      chalkHandler()
 
      const styles = [].slice.call(document.querySelectorAll('style'))
        .filter(style => {
          const text = style.innerText
          return new RegExp(oldVal, 'i').test(text) && !/Chalk Variables/.test(text)
        })
      styles.forEach(style => {
        const { innerText } = style
        if (typeof innerText !== 'string') return
        style.innerText = this.updateStyle(innerText, originalCluster, themeCluster)
      })
 
      this.$emit('change', val)
 
      $message.close()
    }
  },
 
  methods: {
    updateStyle(style, oldCluster, newCluster) {
      let newStyle = style
      oldCluster.forEach((color, index) => {
        newStyle = newStyle.replace(new RegExp(color, 'ig'), newCluster[index])
      })
      return newStyle
    },
 
    getCSSString(url, variable) {
      return new Promise(resolve => {
        const xhr = new XMLHttpRequest()
        xhr.onreadystatechange = () => {
          if (xhr.readyState === 4 && xhr.status === 200) {
            this[variable] = xhr.responseText.replace(/@font-face{[^}]+}/, '')
            resolve()
          }
        }
        xhr.open('GET', url)
        xhr.send()
      })
    },
 
    getThemeCluster(theme) {
      const tintColor = (color, tint) => {
        let red = parseInt(color.slice(0, 2), 16)
        let green = parseInt(color.slice(2, 4), 16)
        let blue = parseInt(color.slice(4, 6), 16)
 
        if (tint === 0) { // when primary color is in its rgb space
          return [red, green, blue].join(',')
        } else {
          red += Math.round(tint * (255 - red))
          green += Math.round(tint * (255 - green))
          blue += Math.round(tint * (255 - blue))
 
          red = red.toString(16)
          green = green.toString(16)
          blue = blue.toString(16)
 
          return `#${red}${green}${blue}`
        }
      }
 
      const shadeColor = (color, shade) => {
        let red = parseInt(color.slice(0, 2), 16)
        let green = parseInt(color.slice(2, 4), 16)
        let blue = parseInt(color.slice(4, 6), 16)
 
        red = Math.round((1 - shade) * red)
        green = Math.round((1 - shade) * green)
        blue = Math.round((1 - shade) * blue)
 
        red = red.toString(16)
        green = green.toString(16)
        blue = blue.toString(16)
 
        return `#${red}${green}${blue}`
      }
 
      const clusters = [theme]
      for (let i = 0; i <= 9; i++) {
        clusters.push(tintColor(theme, Number((i / 10).toFixed(2))))
      }
      clusters.push(shadeColor(theme, 0.1))
      return clusters
    }
  }
}
</script>
 
<style>
.theme-message,
.theme-picker-dropdown {
  z-index: 99999 !important;
}
 
.theme-picker .el-color-picker__trigger {
  height: 26px !important;
  width: 26px !important;
  padding: 2px;
}
 
.theme-picker-dropdown .el-color-dropdown__link-btn {
  display: none;
}
</style>

5、在使用ThemePicker组件的位置，去调用vuex中的changeSetting函数

 <theme-picker style="float: right;height: 26px;margin: -3px 8px 0 0;" @change="themeChange" />
import ThemePicker from '@/components/ThemePicker'
 
export default {
  components: { ThemePicker },
methods:{
  themeChange(val) {
      this.$store.dispatch('settings/changeSetting', {
        key: 'theme',
        value: val
      })
    }
}
}

至此，就可以实现elementUI组件的换肤功能了

总结：其实上边两种方式换肤的实现思路都差不多，下边那篇自己理解得不是很好，欢迎补充