优化页面加载

src/pages/course/learn/item.vue

 <template>
-  <div class="main-container">
+  <div class="main-container" v-show="loaded">
     <div class="course-title">{{detail.course_name}}</div>
     <van-tabs
       class="main-tabs"
@@ -33,6 +33,7 @@ export default {
   data() {
     return {
       tabActive: '0',
+      loaded: false,
       detail: {}
     }
   },
@@ -60,8 +61,9 @@ export default {
         message: '加载中...',
         forbidClick: true
       })
-
+      this.loaded = false
       api.getCourse(this.courseId).then(response => {
+        this.loaded = true
         response.chapters = response.chapters.filter(item => {
           item.children = item.children.filter(child => child.type === 2)
           return item.children.length

src/pages/course/tag/item.vue

 <template>
-  <div class="course-tag-wrapper">
+  <div class="course-tag-wrapper" v-show="loaded">
     <div class="course-tag-hd">
       <h1 class="tag-title">{{detail.title}}</h1>
     </div>
@@ -17,6 +17,7 @@ export default {
   name: 'CourseTagItem',
   data() {
     return {
+      loaded: false,
       detail: {}
     }
   },
@@ -38,7 +39,9 @@ export default {
         message: '加载中...',
         forbidClick: true
       })
+      this.loaded = false
       api.getCourseTag(this.tagId).then(response => {
+        this.loaded = true
         this.detail = response
         this.$toast.clear()
       })
@@ -57,8 +60,11 @@ export default {
   box-sizing: border-box;
 }
 .course-tag-hd {
+  position: sticky;
+  top: 0;
   padding: 0.4rem;
   background-color: #fff;
+  z-index: 10;
 }
 .course-tag-bd {
   padding: 0.4rem;

src/pages/course/tag/list.vue

 <template>
-  <div class="course-tag-wrapper">
+  <div class="course-tag-wrapper" v-show="loaded">
     <div class="course-tag-hd">
       <h1 class="course-title">{{detail.course_name}}</h1>
     </div>
@@ -22,6 +22,7 @@ export default {
   name: 'CourseTagList',
   data() {
     return {
+      loaded: false,
       detail: { chapters: [] }
     }
   },
@@ -53,7 +54,9 @@ export default {
         message: '加载中...',
         forbidClick: true
       })
+      this.loaded = false
       api.getCourseTagList(this.courseId).then(response => {
+        this.loaded = true
         this.detail = response
         this.$toast.clear()
       })
@@ -83,8 +86,11 @@ export default {
   box-sizing: border-box;
 }
 .course-tag-hd {
+  position: sticky;
+  top: 0;
   padding: 0.4rem;
   background-color: #fff;
+  z-index: 10;
 }
 .course-tag-bd {
   padding: 0.4rem;