update:下拉框增加清空

src/modules/teacher/data/exam/components/TitleData.vue

@@ -9,6 +9,7 @@
         placeholder="全部题型"
         @change="changeSeclect"
         style="position: absolute; right: 60px; top: -5px"
+        clearable
       >
         <el-option label="单选题" :value="1"></el-option>
         <el-option label="多选题" :value="2"></el-option>

src/modules/teacher/data/exam/views/ExamData.vue

@@ -21,7 +21,7 @@
             </h1>
           </el-col>
           <el-col :span="10">
-            <el-select v-model="value" placeholder="全部数据" @change="refreshPage">
+            <el-select v-model="value" placeholder="全部数据" @change="refreshPage" clearable>
               <el-option v-for="item in dataInfo.class_map" :key="item.id" :label="item.name" :value="item.id">
               </el-option>
             </el-select>