bug fixes

src/views/Exam.vue

@@ -12,7 +12,12 @@
     </header>
     <div class="exam-main">
       <div class="left scroll" ref="questionRef">
-        <QuestionList :paper="paper" :questionItems="questionItems" :questionNumber="questionNumber" @changeNumber="changeNumber" v-if="questionItems.length"></QuestionList>
+        <QuestionList
+          :paper="paper"
+          :questionItems="questionItems"
+          :questionNumber="questionNumber"
+          @changeNumber="number => changeNumber(number, false)"
+          v-if="questionItems.length"></QuestionList>
       </div>
       <div class="right scroll">
         <QuestionNum :questionItems="questionItems" :questionNumber="questionNumber" :student="studentInfo" @changeNumber="changeNumber"></QuestionNum>
@@ -275,9 +280,9 @@ export default {
     handleNext() {
       this.changeNumber(this.questionNumber + 1)
     },
-    changeNumber(number) {
+    changeNumber(number, isBackTop = true) {
       this.questionNumber = number
-      this.$refs.questionRef.scrollTo(0, 0)
+      isBackTop && this.$refs.questionRef.scrollTo(0, 0)
     }
   }
 }