新增上一页功能，BGM自动引入

src/components/Question.vue

@@ -13,7 +13,7 @@
                 <!-- 查看结果 -->
                 <Button v-if="showResultBtn" @click="showResult">查看结果</Button>
                 <!-- 下一页 -->
-                <Button @click="nextPage">下一页</Button>
+                <Button v-show="currentId != 0" @click="prevePage">上一页</Button>
             </div>
         </div>
     </div>
@@ -40,11 +40,19 @@ const answerFn = (item, event) => {
     activeId.value = item.aid
     debounceTap(e, () => {
         let cid = questionList.value[currentId.value].id
-        answerList.value.push({
-            qid: cid,
-            answer: item.secore,
-            text: item.text
-        })
+        let has = answerList.value.findIndex(obj => obj.qid === cid);
+        if (has == -1) {
+            answerList.value.push({
+                qid: cid,
+                answer: item.secore,
+                text: item.text
+            })
+        } else {
+            answerList.value[has].answer = item.secore
+            answerList.value[has].text = item.text
+        }
+
+        // 更新下一题信息
         if (currentId.value >= 11) {
             Toast('答题结束')
             console.log('答题结束');
@@ -56,7 +64,7 @@ const answerFn = (item, event) => {
             currentId.value++
         }
 
-        // console.log('答案库', answerList.value);
+        console.log('答案库', answerList.value);
 
     })
 }
@@ -80,10 +88,17 @@ const showResult = (event) => {
     })
 }
 
-const nextPage = () => {
-
+// 上一页函数
+const prevePage = (event) => {
+    let e = event.target
+    debounceTap(e, () => {
+        activeId.value = ''
+        currentId.value--
+    })
 }
 
+
+
 </script>
 
 <style lang='scss' scope>