遮挡层时防止触摸穿透

<view class="content" :catchtouchmove="true">
        加载中。。。
</view>

模糊背景

.content_BG{
        position: absolute;
        left: 0;
        top: 0;
        right: 0;
        bottom: 0;
        image{
            width: 100%;
            height: 100%;
        }
        filter: blur(8rpx);
        opacity: 0.3;
    }

文本显示两行，多余显示省略号

display:-webkit-box;

-webkit-box-orient:vertical;

-webkit-line-clamp:2;

overflow:hidden;

三元表达式动态添加类

<ordering :class="[activeIndex === 0 ? 'successClass' : 'errClass']"></ordering>

数组去重，数组去空， 数组合并

let oldArr = [1, 1, 2, 2, 2, 3, '', '']
//数组去重
let newArr = Array.from(new Set(oldArr))
//数组去重 2
computed:{
    calculation(){
    // 监听总价
    // 1数组对象去重 :累加器：reduce()
    let arr = {}
    let arrdata = this.arrtotalPrice.reduce((preVal,curVal)=>{
    arr[curVal.indexs] ? '' : arr[curVal.indexs] = true && preVal.push(curVal)
    return preVal
  },[])
}
//数组去空值
let newArr2 = newArr2.filter(item => item)
//数组合并
let arr = ['全部', ...newArr]

给数组中的对象添加键值

newValue.map( item => {
      let key = 'amount'
      let num = 0
      return item[key] = num
})

给文字添加下划线 删除线

text-decoration: line-through;

JS去除浮点数

let allPrice = this.count * Discount
//去除总价浮点数
let TotalNum = parseFloat((allPrice).toFixed(10))

Koa 解决跨域问题

1. npm下载 koa-cors
   $ npm install koa-cors
2. 主函数写如下代码

var koa = require('koa');
var route = require('koa-route');
var cors = require('koa-cors');
var app = koa();
 
app.use(cors());
 
app.use(route.get('/', function() {
  this.body = { msg: 'Hello World!' };
}));
 
app.listen(3000);

关键代码

var cors = require('koa-cors');
app.use(cors());