fix kkFile预览提出公共方法，加水印

src/utils/kkFilePreview.js

@@ -0,0 +1,19 @@
+import Vue from 'vue'
+import { USER_INFO } from '../store/mutation-types'
+import { Base64 } from 'js-base64'
+
+const md5 = require('md5')
+
+/**
+ * kkFile预览文件并添加水印
+ * @param fileUrl
+ */
+export const kkFilePreview = (fileUrl) => {
+  const userInfo = Vue.ls.get(USER_INFO)
+  // 水印内容
+  const watermarkTxt = `${userInfo.username} ${userInfo.realname}`
+  // 客户环境预览需要加的加密参数
+  const watermarkSign = md5(watermarkTxt, 'cnhtc')
+  const url = `${window._CONFIG.onlinePreviewDomainURL}?url=${encodeURIComponent(Base64.encode(fileUrl))}&watermarkTxt=${encodeURIComponent(watermarkTxt)}&watermarkSign=${watermarkSign}`
+  window.open(url)
+}