I want to implement a list of cloud disks, showing folder, xls, pdf, png and other file types. When using v-for to loop cell, add v-if to judge fileType, to further change the icon in slot. But when you modify it in img alone, you will get an error, saying that v-else-if must be placed after using the adjacent elements of v-if. Do not know how to change, ask orz for advice. 
 this is the page code 
<mt-index-list>
        <mt-cell v-for="file in fileList" :key="file.fileId" 
                :title="file.fileName" 
                @click.native="change(file.fileName)"  
                label="">
            <img slot="icon" v-if="file.fileType ==="folder"" style="width:30px;height:30px" src="../../assets/folder.png"/><i class="iconfont icon-arrow-right-copy-copy"></i>
            <img slot="icon" v-else-if="file.fileType ==="xls"" style="width:30px;height:30px" src="../../assets/excel.png"/>
        </mt-cell>
<mt-index-list>this is the returned data
fileList:[{
        fileId:"1",
        fileSize:0,
        fileName:"1",
        fileType:"folder"
      },{
        fileId:"2",
        fileSize:0,
        fileName:"2",
        fileType:"doc"
      },{
        fileId:"3",
        fileSize:0,
        fileName:"3",
        fileType:"folder"
      },{
        fileId:"4",
        fileSize:0,
        fileName:"4",
        fileType:"folder"
      },{
        fileId:"5",
        fileSize:0,
        fileName:"5",
        fileType:"folder"
      }],expected effect
 

v-ifmt-cell
 
 
also ask the gods to give us some advice on how to change it
