Vue img: src splicing problem

<img v-if="scope.row" :src= "this.$api.imgServer.down+scope.row.coverImage" style="width: 100px;height: 100px; "/>
< hr >

where scope.row.coverImage is taken out as file-uploads/cf.png, and this.$api.imgServer.down is the address for server image management, which shows that imgServer is not defined.
Let me write let pic = this.$api.imgServer.down; in mounted (), and then src = "pic + scope.row.coverImage" will report the error of roperty or method "pic" is not defined on the instance but referenced during
how should I spell it

Just after publishing the question,

suddenly came up with the idea of writing return this.$api.cfg.imgServer.down in computed (). As a calculation attribute, and then splice it into src to successfully solve the problem 

 picUrl(){
      return this.$api.cfg.imgServer.down
    }
<img v-if="scope.row" :src= "picUrl()+scope.row.coverImage" style="width: 100px;height: 100px; "/>
< hr >
Vue.js
Oct.13,2021

the this here is written directly in the html tag. You don't know what it means.
you can try it like this. 

<img v-if="scope.row" :src= "getImgUrl(scope.row)" style="width: 100px;height: 100px; "/>
method:{
    getImgUrl(row){
        return this.$api.imgServer.down+row.coverImage;
    }
}

Previous: How to prevent the front-end js from being tampered with?

Next: WeChat Mini Programs gets the attribute value

css mysql arrays josn react html typescript webpack npm sass R objective-c .net sql-server jquery python-3.x angularjs django angular excel regex iphone ajax linux xml pandas vba spring database wordpress string wpf xcode windows bash postgresql oracle multithreading eclipse list firebase algorithm macos forms image scala visual-studio azure bootstrap spring-boot react-native python-2.7 docker performance function winforms matlab powershell apache dataframe api sqlite numpy rest shell selenium flutter dart maven loops qt swing android-studio csv express file class tensorflow sorting codeigniter perl
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b3663d-4d6aa.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b3663d-4d6aa.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?