修改

src/components/course/classinfo-form.vue

@@ -98,7 +98,7 @@
                 <q-input square filled v-model="dropMsg.DropOutRemark" borderless label="退课原因" ref="reason" type="textarea" counter 
                   :rules="[val => !!val || '请填写退课原因']" maxlength="200" />
                 <div class="drop_NameDown">
-                    <q-chip v-for="item in selectedStudent">
+                    <q-chip v-for="(item,index) in selectedStudent" :key="index">
                       <q-avatar rounded size="sm" v-if="item.UserIcon">
                         <img :src="item.UserIcon" />
                       </q-avatar>