请求二进制流文件，并转码下载

exportExcel () {

var str = '?'

for (var i in this.search) {

str += i + '=' + (this.search[i] || '')

}

this.loading.start()

this.$http({

url: this.exportUrl,

method: 'get',

params: this.search,

responseType: 'blob' //转码

})

.then((res) => {

const blob = new Blob([res.data], { type: "application/x-xls" })

// 兼容不同浏览器的URL对象

const url = window.URL || window.webkitURL || window.moxURL

// 创建下载链接

const downloadHref = url.createObjectURL(blob)

// 创建a标签并为其添加属性

let downloadLink = document.createElement('a')

downloadLink.href = downloadHref

downloadLink.download = '项目回款情况差异表.xls';

// 触发点击事件执行下载

downloadLink.click()

})

.finally(() => {

this.loading.stop()

})

}