做批发的在什么网站拿货营业推广方式

下面是报错，同一情况下，不同的浏览器给出的各种错误:

◎typeerror is undefined

◎Windows. SessionStorage is undefined

◎Module is undefined ,axios...

◎_txc member is undefined 

这些其实都指向一个问题，某个数据是空的。

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情况：我们知道前端可以去后端拿数据，也可以后端传过来后就在前端拿数据，我选择的是前端需要的数据就在前端页面上拿，但前端页面是空的，所以报错 为空异常。

相关代码：

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//  store/index.jsimport { createStore } from 'vuex'const MEMBER = "MEMBER";export default createStore({state: {member: window.SessionStorage.get(MEMBER) || {}},getters: {},mutations: {setMember (state, _member) {state.member = _member;window.SessionStorage.set(MEMBER, _member);}},actions: {},modules: {}
})// SessionStorage.jsSessionStorage = {get: function (key) {var v = sessionStorage.getItem(key);if (v && typeof(v) !== "undefined" && v !== "undefined") {return JSON.parse(v);}},set: function (key, data) {sessionStorage.setItem(key, JSON.stringify(data));},remove: function (key) {sessionStorage.removeItem(key);},clearAll: function () {sessionStorage.clear();}
};
----------------------------------------------------------------------------//vue<a-select v-model:value="passenger.type"><a-select-option v-for="item in PASSENGER_TYPE_ARRAY" :key="item.code" :value="item.code">{{item.desc}}</a-select-option>setup() {const PASSENGER_TYPE_ARRAY = window.PASSENGER_TYPE_ARRAY;//省略
}//enums.jsPASSENGER_TYPE_ARRAY=[{code:"1", desc:"成人"},{code:"2", desc:"儿童"},{code:"3", desc:"学生"}];

解决方法:

主要是两大块同时出现了问题  1. sessionStorage   2.PASSENGER_TYPE_ARRAY

注释掉前端用到这两个东西的地方，修改代码，运行，然后再把注释去掉，再运行。

1. sessionStorage 

store/index.js  先注释掉window.SessionStorage相关内容
运行后端和前端，然后再去掉注释，运行
---------------------------------------------------------------------import { createStore } from 'vuex'// const MEMBER = "MEMBER";export default createStore({state: {member: {}// member: window.SessionStorage.get(MEMBER) || {}},getters: {},mutations: {setMember (state, _member) {state.member = _member;// window.SessionStorage.set(MEMBER, _member);}},actions: {},modules: {}
})SessionStorage.js 全部注释掉
----------------------------
SessionStorage = {get: function (key) {var v = sessionStorage.getItem(key);if (v && typeof(v) !== "undefined" && v !== "undefined") {return JSON.parse(v);}},set: function (key, data) {sessionStorage.setItem(key, JSON.stringify(data));},remove: function (key) {sessionStorage.removeItem(key);},clearAll: function () {sessionStorage.clear();}
};

2.PASSENGER_TYPE_ARRAY

后端本来为key code，然后修改为code desc 导致缓存不一致，获取为空。
分两步，先不修改为code desc，运行；再修改，再运行
-------------------------------------------------------------
-》修改为这样：运行后，打开前端查看，再改回去运行，就可以了。
//vue<a-select v-model:value="passenger.type"><a-select-option v-for="item in PASSENGER_TYPE_ARRAY" :key="item.key" :value="item.key">{{item.code}}</a-select-option>setup() {const PASSENGER_TYPE_ARRAY = [{key:"1", code:"成人"},{key:"2", code:"儿童"},{key:"3", code:"学生"}];//省略
}//enums.jsPASSENGER_TYPE_ARRAY=[{key:"1", code:"成人"},{key:"2", code:"儿童"},{key:"3", code:"学生"}];
---------------------------------------------------------------------
改回去：//vue<a-select v-model:value="passenger.type"><a-select-option v-for="item in PASSENGER_TYPE_ARRAY" :key="item.code" :value="item.code">{{item.desc}}</a-select-option>setup() {const PASSENGER_TYPE_ARRAY = window.PASSENGER_TYPE_ARRAY;//省略
}//enums.jsPASSENGER_TYPE_ARRAY=[{code:"1", desc:"成人"},{code:"2", desc:"儿童"},{code:"3", desc:"学生"}];