perview(row){
const typeArr = ['doc', 'docx', 'ppt', 'pptx', 'xls', 'xlsx']
let arr=row.url.split('.')
let fileType=arr[arr.length-1]
let url = ''
if (typeArr.indexOf(fileType) !== -1) {
// 使用微软的office online
url='http://view.xdocin.com/xdoc?_xdoc='+row.url
} else {
url = row.url
}
// window.open()居中打开
const width = 1000; const height = 800
const top = (window.screen.availHeight - height) / 2
const left = (window.screen.availWidth - width) / 2
window.open(url, '', 'width=' + width + ',height=' + height + ',top=' + top + ',left=' + left)
}