Vue问题-- Property or method "showHistoryR" is not defined on the instance but referenced

问题：
属于vue.js 597行问题

Property or method "showHistoryR" is not defined on the instance but 
referenced during render. Make sure that this property is reactive, 
either in the data option, or for class-based components, by 
initializing the property. See: 
https://vuejs.org/v2/guide/reactivity.html#Declaring-Reactive-Properties.

解决方法：
1.先查看methods是否写成“method”等错误内容
2.查看html中使用的方法或变量，没有在new vue()中定义