updates

src/modules/school/class/components/AddStudent.vue

 <template>
-  <el-dialog v-bind="$attrs" v-on="$listeners" width="25%" top="40vh">
+  <el-dialog title="添加学员" v-bind="$attrs" v-on="$listeners" width="400px" :close-on-click-modal="false">
     <el-form ref="formRef" :model="form">
-      <el-form-item label="学员" prop="personal_name">
-        <el-select v-model="form.students_id" multiple placeholder="请选择学员">
+      <el-form-item prop="personal_name">
+        <el-select v-model="form.students_id" multiple placeholder="请选择学员" style="width: 100%">
           <el-option v-for="item in detail" :key="item.index" :value="item.id" :label="item.personal_name"></el-option>
         </el-select>
       </el-form-item>
-      <el-form-item>
-        <el-button @click="$emit('update:visible', false)" style="margin-left: 50px">取消</el-button>
-        <el-button type="primary" style="margin-left: 20px" @click="submit">提交</el-button>
-      </el-form-item>
     </el-form>
+    <template #footer>
+      <el-button @click="$emit('update:visible', false)">取消</el-button>
+      <el-button type="primary" @click="submit">提交</el-button>
+    </template>
   </el-dialog>
 </template>
 

src/modules/school/class/components/AddTeacher.vue

 <template>
-  <el-dialog v-bind="$attrs" v-on="$listeners" width="25%" top="40vh">
+  <el-dialog title="添加教师" v-bind="$attrs" v-on="$listeners" width="400px" :close-on-click-modal="false">
     <el-form ref="formRef" :model="form">
-      <el-form-item label="教师" prop="personal_name">
-        <el-select v-model="form.staffs_id" multiple placeholder="请选择教师">
+      <el-form-item prop="personal_name">
+        <el-select v-model="form.staffs_id" multiple placeholder="请选择教师" style="width: 100%">
           <el-option v-for="item in detail" :key="item.index" :value="item.id" :label="item.personal_name"></el-option>
         </el-select>
       </el-form-item>
-      <el-form-item>
-        <el-button @click="$emit('update:visible', false)" style="margin-left: 50px">取消</el-button>
-        <el-button type="primary" style="margin-left: 20px" @click="submit">提交</el-button>
-      </el-form-item>
     </el-form>
+    <template #footer>
+      <el-button @click="$emit('update:visible', false)">取消</el-button>
+      <el-button type="primary" @click="submit">提交</el-button>
+    </template>
   </el-dialog>
 </template>
 

src/modules/school/class/components/ClassExamAdd.vue

 <template>
-  <el-dialog title="添加考试" v-bind="$attrs" v-on="$listeners" width="400px" align="center">
+  <el-dialog title="添加考试" v-bind="$attrs" v-on="$listeners" width="400px" :close-on-click-modal="false">
     <el-form ref="form" :model="form" :rules="rules">
       <el-form-item prop="exams_id">
         <el-select v-model="form.exams_id" multiple filterable placeholder="请选择考试" style="width: 100%">