vue数据请求显示loading图

一般项目中，有时候会要求，你在数据请求的时候显示一张gif图片，然后数据加载完后，消失。这个，一般只需要在封装的axios中写入js事件即可。当然，我们首先需要在app.vue中，加入此图片。如下：

<template>
<div id="app">
<loading v-show="fetchLoading"></loading>
<router-view></router-view>
</div>
</template><script>
import { mapGetters } from 'vuex';
import Loading from './components/common/loading'; export default {
name: 'app',
data() {
return {
}
},
computed: {
...mapGetters([
'fetchLoading',
]),
},
components: {
Loading,
}
}
</script><style>
#app{
width: 100%;
height: 100%;
}
</style>

这里的fetchLoading是存在vuex里面的一个变量。在store/modules/common.js里需要如下定义：

/* 此js文件用于存储公用的vuex状态 */
import api from './../../fetch/api'
import * as types from './../types.js'
const state = {
// 请求数据时加载状态loading
fetchLoading: false
}
const getters = {
// 请求数据时加载状态
fetchLoading: state => state.fetchLoading
}
const actions = {
// 请求数据时状态loading
FETCH_LOADING({
commit
}, res) {
commit(types.FETCH_LOADING, res)
},
}
const mutations = {
// 请求数据时loading
[types.FETCH_LOADING] (state, res) {
state.fetchLoading = res
}
}

loading组件如下：

<template>
<div class="loading">
<img src="./../../assets/main/running.gif" alt="">
</div>
</template><script>
export default {
name: 'loading',
data () {
return {}
},
}
</script>
<!-- Add "scoped" attribute to limit CSS to this component only -->
<style scoped>
.loading{
position: fixed;
top:0;
left:0;
z-index:121;
width: 100%;
height: 100%;
background: rgba(0,0,0,0.3);
display: table-cell;
vertical-align: middle;
text-align: center;
}
.loading img{
margin:5rem auto;
}
</style>

最后在fetch/api.js里封装的axios里写入判断loading事件即可：如下

// axios的请求时间
let axiosDate = new Date()
export function fetch (url, params) {
return new Promise((resolve, reject) => {
axios.post(url, params)
.then(response => {
// 关闭 loading图片消失
let oDate = new Date()
let time = oDate.getTime() - axiosDate.getTime()
if (time < 500) time = 500
setTimeout(() => {
store.dispatch('FETCH_LOADING', false)
}, time)
resolve(response.data)
})
.catch((error) => {
// 关闭 loading图片消失
store.dispatch('FETCH_LOADING', false)
axiosDate = new Date()
reject(error)
})
})
}
export default {
// 组件中公共页面请求函数
commonApi (url, params) {
if(stringQuery(window.location.href)) {
store.dispatch('FETCH_LOADING', true);
}
axiosDate = new Date();
return fetch(url, params);
}
}