2022.10.19

1.js将十六进制颜色转透明度的函数

function getHexOpacityColor({color = '#000',opacity = 0.5}){
  opacity = Math.max(opacity,0);
  opacity = Math.min(opacity,1);
  color = color.replace(/#/g,'').toUpperCase();
  if(color.length === 3){
    let arr = color.split('');
    color = '';
    for (let i = 0; i < arr.length; i++) {
      color += (arr[i] + arr[i]);//将简写的3位字符补全到6位字符
    }
  }
  let num = Math.round(255 * opacity);//四舍五入
  let str = '';
  let arrHex = ["0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F"];//十六进制数组
  while (num>0) {
      let mod = num % 16;
      num = (num - mod) / 16;
      str = arrHex[mod] + str;
  }
  if(str.length == 1)str = '0' + str;
  if(str.length == 0)str = '00';
  return `#${color+str}`;
}
getHexOpacityColor({color:'#f00',opacity:0.5});

下面将0-100%透明度输出

function getHexOpacity({opacity = 0.5}){
  opacity = Math.max(opacity,0);
  opacity = Math.min(opacity,1);
  let num = Math.round(255 * opacity);//向下取整
  let str = '';
  let arrHex = ["0","1","2","3","4","5","6","7","8","9","A","B","C","D","E","F"];//十六进制数组
  while (num>0) {
      let mod = num % 16;
      num = (num - mod) / 16;
      str = arrHex[mod] + str;
  }
  if(str.length == 1)str = '0' + str;
  if(str.length == 0)str = '00';
  return `${str}`;
}
//输出0-100的透明度（16进制）
var all = '';
for (var i = 0; i <= 100; i++) {
  let opacity = i / 100;
  let str = getHexOpacity({opacity});
  all += `\n${i}% — ${str}`;
}
console.log(all);

2.elementui中el-input-number组件加减法失效问题,由于v-model绑定的数据层级过深导致加减实效

3.一个元素同时具有单击事件,拖拽事件,其中时间的执行顺序是:

鼠标按下事件中的回调 -> 鼠标移动事件中的回调 -> 鼠标抬起事件中的回调 -> 绑定的click事件中的回调

4.vue中scss实现一键切换主题色

1.新建一个Scss文件_themes.scss，里面可以配置不同的主题配色方案

//当HTML的data-theme为dark时，样式引用dark
//data-theme为其他值时，就采用组件库的默认样式
//这里我只定义了两套主题方案，想要再多只需在`$themes`里加就行了
//注意一点是，每套配色方案里的key可以自定义但必须一致，不然就会混乱
 
$themes: (
 
light: (
//字体
font_color1: #414141,
font_color2: white,
 
//背景
background_color1: #fff,
background_color2: #f0f2f5,
background_color3: red,
background_color4: #2674e7,
 
//边框
border_color1: #3d414a,
 
),
 
dark: (
//字体
font_color1: #a7a7a7,
font_color2: white,
 
//背景
background_color1: #1b2531,
background_color2: #283142,
background_color3: #1e6ceb,
background_color4: #323e4e,
 
//边框
border_color1: #3d414a,
 
)
);

2.定义另外一个sass文件_handle.scss来操作1中的$theme变量（当然两个文件可以合并，分开写是想把配置和操作解耦）

@import "./_themes.scss";
 
//遍历主题map
@mixin themeify {
@each $theme-name, $theme-map in $themes {
//!global 把局部变量强升为全局变量
$theme-map: $theme-map !global;
//判断html的data-theme的属性值  #{}是sass的插值表达式
//& sass嵌套里的父容器标识   @content是混合器插槽，像vue的slot
[data-theme="#{$theme-name}"] & {
@content;
}
}
}
 
//声明一个根据Key获取颜色的function
@function themed($key) {
@return map-get($theme-map, $key);
}
 
//获取背景颜色
@mixin background_color($color) {
@include themeify {
background-color: themed($color)!important;
}
}
 
//获取字体颜色
@mixin font_color($color) {
@include themeify {
color: themed($color)!important;
}
}
 
//获取边框颜色
@mixin border_color($color) {
@include themeify {
border-color: themed($color)!important;
}
}

themeify方法用于获取HTML的 data-theme值。
themed方法用于根据HTML的 data-theme值及调用者传过来的key去 _themes.scss里获取相应的颜色。

3.具体在vue中使用，直接引入对应混入器就好，取哪个颜色，传哪个key，就这么简

<style lang="scss" scoped>
  @import "@/style/_handle.scss";
 
  .common-util {
    font-size: 18px;
    @include font_color("font_color1");
    @include background_color("background_color1");
    @include border_color("border_color1");
  }
</style>

4.使用js动态切换HTML的属性data-theme的值

**html**
<DropdownMenu slot="list">
  <DropdownItem @click.native="theme('iview')">默认</DropdownItem>
  <DropdownItem @click.native="theme('light')">浅色</DropdownItem>
  <DropdownItem @click.native="theme('dark')">深色</DropdownItem>
</DropdownMenu>



//换主题 **js**
theme(type) {
this.$store.commit('upDate', {themeType: type});
window.document.documentElement.setAttribute( "data-theme", type );
}