Update PreviewTable.vue

src/component/PreviewTable.vue

@@ -3,7 +3,8 @@
     <el-table-column label="封面">
       <template slot-scope="scope">
         <el-upload :auto-upload="false" :show-file-list="true" :on-change="chageCover" action="" drag>
-          <img :src="scope.row.picture" style="width: 100px; height: 100px">
+          <img v-if="imageUrl" width="100px" height="100px" :src="imageUrl" />
+          <img v-else :src="scope.row.picture" style="width: 100px; height: 100px">
             <div slot="error" class="image-slot el-image__error">暂无封面</div>
           </img>
         </el-upload>
@@ -58,6 +59,7 @@ export default {
       this.$emit('download', row);
     },
     changeCover(file) {
+      imageUrl=file.url;
     },
   },
 };