| <template> | 
|     <!-- 支付宝小程序使用$u.getRect()获取组件的根元素尺寸,所以在外面套一个"壳" --> | 
|     <view> | 
|         <view class="u-index-bar"> | 
|             <slot /> | 
|             <view v-if="showSidebar" class="u-index-bar__sidebar" @touchstart.stop.prevent="onTouchMove" @touchmove.stop.prevent="onTouchMove" | 
|              @touchend.stop.prevent="onTouchStop" @touchcancel.stop.prevent="onTouchStop"> | 
|                 <view v-for="(item, index) in indexList" :key="index" class="u-index-bar__index" :style="{zIndex: zIndex + 1, color: activeAnchorIndex === index ? activeColor : ''}" | 
|                  :data-index="index"> | 
|                     {{ item }} | 
|                 </view> | 
|             </view> | 
|             <view class="u-indexed-list-alert" v-if="touchmove && indexList[touchmoveIndex]" :style="{ | 
|                 zIndex: alertZIndex | 
|             }"> | 
|                 <text>{{indexList[touchmoveIndex]}}</text> | 
|             </view> | 
|         </view> | 
|     </view> | 
| </template> | 
|   | 
| <script> | 
|     var indexList = function() { | 
|         var indexList = []; | 
|         var charCodeOfA = 'A'.charCodeAt(0); | 
|         for (var i = 0; i < 26; i++) { | 
|             indexList.push(String.fromCharCode(charCodeOfA + i)); | 
|         } | 
|         return indexList; | 
|     }; | 
|   | 
|     /** | 
|      * indexList 索引列表 | 
|      * @description 通过折叠面板收纳内容区域,搭配<u-index-anchor>使用 | 
|      * @tutorial https://www.uviewui.com/components/indexList.html#indexanchor-props | 
|      * @property {Number String} scroll-top 当前滚动高度,自定义组件无法获得滚动条事件,所以依赖接入方传入 | 
|      * @property {Array} index-list 索引字符列表,数组(默认A-Z) | 
|      * @property {Number String} z-index 锚点吸顶时的层级(默认965) | 
|      * @property {Boolean} sticky 是否开启锚点自动吸顶(默认true) | 
|      * @property {Number String} offset-top 锚点自动吸顶时与顶部的距离(默认0) | 
|      * @property {String} highlight-color 锚点和右边索引字符高亮颜色(默认#2979ff) | 
|      * @event {Function} select 选中右边索引字符时触发 | 
|      * @example <u-index-list :scrollTop="scrollTop"></u-index-list> | 
|      */ | 
|     export default { | 
|         name: "u-index-list", | 
|         props: { | 
|             sticky: { | 
|                 type: Boolean, | 
|                 default: true | 
|             }, | 
|             zIndex: { | 
|                 type: [Number, String], | 
|                 default: '' | 
|             }, | 
|             scrollTop: { | 
|                 type: [Number, String], | 
|                 default: 0, | 
|             }, | 
|             offsetTop: { | 
|                 type: [Number, String], | 
|                 default: 0 | 
|             }, | 
|             indexList: { | 
|                 type: Array, | 
|                 default () { | 
|                     return indexList() | 
|                 } | 
|             }, | 
|             activeColor: { | 
|                 type: String, | 
|                 default: '#2979ff' | 
|             } | 
|         }, | 
|         created() { | 
|             // #ifdef H5 | 
|             this.stickyOffsetTop = this.offsetTop ? uni.upx2px(this.offsetTop) : 44; | 
|             // #endif | 
|             // #ifndef H5 | 
|             this.stickyOffsetTop = this.offsetTop ? uni.upx2px(this.offsetTop) : 0; | 
|             // #endif | 
|             // 只能在created生命周期定义children,如果在data定义,会因为循环引用而报错 | 
|             this.children = []; | 
|         }, | 
|         data() { | 
|             return { | 
|                 activeAnchorIndex: 0, | 
|                 showSidebar: true, | 
|                 // children: [], | 
|                 touchmove: false, | 
|                 touchmoveIndex: 0, | 
|             } | 
|         }, | 
|         watch: { | 
|             scrollTop() { | 
|                 this.updateData() | 
|             } | 
|         }, | 
|         computed: { | 
|             // 弹出toast的z-index值 | 
|             alertZIndex() { | 
|                 return this.$u.zIndex.toast; | 
|             } | 
|         }, | 
|         methods: { | 
|             updateData() { | 
|                 this.timer && clearTimeout(this.timer); | 
|                 this.timer = setTimeout(() => { | 
|                     this.showSidebar = !!this.children.length; | 
|                     this.setRect().then(() => { | 
|                         this.onScroll(); | 
|                     }); | 
|                 }, 0); | 
|             }, | 
|             setRect() { | 
|                 return Promise.all([ | 
|                     this.setAnchorsRect(), | 
|                     this.setListRect(), | 
|                     this.setSiderbarRect() | 
|                 ]); | 
|             }, | 
|             setAnchorsRect() { | 
|                 return Promise.all(this.children.map((anchor, index) => anchor | 
|                     .$uGetRect('.u-index-anchor-wrapper') | 
|                     .then((rect) => { | 
|                         Object.assign(anchor, { | 
|                             height: rect.height, | 
|                             top: rect.top | 
|                         }); | 
|                     }))); | 
|             }, | 
|             setListRect() { | 
|                 return this.$uGetRect('.u-index-bar').then((rect) => { | 
|                     Object.assign(this, { | 
|                         height: rect.height, | 
|                         top: rect.top + this.scrollTop | 
|                     }); | 
|                 }); | 
|             }, | 
|             setSiderbarRect() { | 
|                 return this.$uGetRect('.u-index-bar__sidebar').then(rect => { | 
|                     this.sidebar = { | 
|                         height: rect.height, | 
|                         top: rect.top | 
|                     }; | 
|                 }); | 
|             }, | 
|             getActiveAnchorIndex() { | 
|                 const { | 
|                     children | 
|                 } = this; | 
|                 const { | 
|                     sticky | 
|                 } = this; | 
|                 for (let i = this.children.length - 1; i >= 0; i--) { | 
|                     const preAnchorHeight = i > 0 ? children[i - 1].height : 0; | 
|                     const reachTop = sticky ? preAnchorHeight : 0; | 
|                     if (reachTop >= children[i].top) { | 
|                         return i; | 
|                     } | 
|                 } | 
|                 return -1; | 
|             }, | 
|             onScroll() { | 
|                 const { | 
|                     children = [] | 
|                 } = this; | 
|                 if (!children.length) { | 
|                     return; | 
|                 } | 
|                 const { | 
|                     sticky, | 
|                     stickyOffsetTop, | 
|                     zIndex, | 
|                     scrollTop, | 
|                     activeColor | 
|                 } = this; | 
|                 const active = this.getActiveAnchorIndex(); | 
|                 this.activeAnchorIndex = active; | 
|                 if (sticky) { | 
|                     let isActiveAnchorSticky = false; | 
|                     if (active !== -1) { | 
|                         isActiveAnchorSticky = | 
|                             children[active].top <= 0; | 
|                     } | 
|                     children.forEach((item, index) => { | 
|                         if (index === active) { | 
|                             let wrapperStyle = ''; | 
|                             let anchorStyle = { | 
|                                 color: `${activeColor}` | 
|                             }; | 
|                             if (isActiveAnchorSticky) { | 
|                                 wrapperStyle = { | 
|                                     height: `${children[index].height}px` | 
|                                 }; | 
|                                 anchorStyle = { | 
|                                     position: 'fixed', | 
|                                     top: `${stickyOffsetTop}px`, | 
|                                     zIndex: `${zIndex ? zIndex : this.$u.zIndex.indexListSticky}`, | 
|                                     color: `${activeColor}` | 
|                                 }; | 
|                             } | 
|                             item.active = active; | 
|                             item.wrapperStyle = wrapperStyle; | 
|                             item.anchorStyle = anchorStyle; | 
|                         } else if (index === active - 1) { | 
|                             const currentAnchor = children[index]; | 
|                             const currentOffsetTop = currentAnchor.top; | 
|                             const targetOffsetTop = index === children.length - 1 ? | 
|                                 this.top : | 
|                                 children[index + 1].top; | 
|                             const parentOffsetHeight = targetOffsetTop - currentOffsetTop; | 
|                             const translateY = parentOffsetHeight - currentAnchor.height; | 
|                             const anchorStyle = { | 
|                                 position: 'relative', | 
|                                 transform: `translate3d(0, ${translateY}px, 0)`, | 
|                                 zIndex: `${zIndex ? zIndex : this.$u.zIndex.indexListSticky}`, | 
|                                 color: `${activeColor}` | 
|                             }; | 
|                             item.active = active; | 
|                             item.anchorStyle = anchorStyle; | 
|                         } else { | 
|                             item.active = false; | 
|                             item.anchorStyle = ''; | 
|                             item.wrapperStyle = ''; | 
|                         } | 
|                     }); | 
|                 } | 
|             }, | 
|             onTouchMove(event) { | 
|                 this.touchmove = true; | 
|                 const sidebarLength = this.children.length; | 
|                 const touch = event.touches[0]; | 
|                 const itemHeight = this.sidebar.height / sidebarLength; | 
|                 let clientY = 0; | 
|                 clientY = touch.clientY; | 
|                 let index = Math.floor((clientY - this.sidebar.top) / itemHeight); | 
|                 if (index < 0) { | 
|                     index = 0; | 
|                 } else if (index > sidebarLength - 1) { | 
|                     index = sidebarLength - 1; | 
|                 } | 
|                 this.touchmoveIndex = index; | 
|                 this.scrollToAnchor(index); | 
|             }, | 
|             onTouchStop() { | 
|                 this.touchmove = false; | 
|                 this.scrollToAnchorIndex = null; | 
|             }, | 
|             scrollToAnchor(index) { | 
|                 if (this.scrollToAnchorIndex === index) { | 
|                     return; | 
|                 } | 
|                 this.scrollToAnchorIndex = index; | 
|                 const anchor = this.children.find((item) => item.index === this.indexList[index]); | 
|                 if (anchor) { | 
|                     this.$emit('select', anchor.index); | 
|                     uni.pageScrollTo({ | 
|                         duration: 0, | 
|                         scrollTop: anchor.top + this.scrollTop | 
|                     }); | 
|                 } | 
|             } | 
|         } | 
|     }; | 
| </script> | 
|   | 
| <style lang="scss" scoped> | 
|     @import "../../libs/css/style.components.scss"; | 
|      | 
|     .u-index-bar { | 
|         position: relative | 
|     } | 
|   | 
|     .u-index-bar__sidebar { | 
|         position: fixed; | 
|         top: 50%; | 
|         right: 0; | 
|         @include vue-flex; | 
|         flex-direction: column; | 
|         text-align: center; | 
|         transform: translateY(-50%); | 
|         user-select: none; | 
|         z-index: 99; | 
|     } | 
|   | 
|     .u-index-bar__index { | 
|         font-weight: 500; | 
|         padding: 8rpx 18rpx; | 
|         font-size: 22rpx; | 
|         line-height: 1 | 
|     } | 
|   | 
|     .u-indexed-list-alert { | 
|         position: fixed; | 
|         width: 120rpx; | 
|         height: 120rpx; | 
|         right: 90rpx; | 
|         top: 50%; | 
|         margin-top: -60rpx; | 
|         border-radius: 24rpx; | 
|         font-size: 50rpx; | 
|         color: #fff; | 
|         background-color: rgba(0, 0, 0, 0.65); | 
|         @include vue-flex; | 
|         justify-content: center; | 
|         align-items: center; | 
|         padding: 0; | 
|         z-index: 9999999; | 
|     } | 
|   | 
|     .u-indexed-list-alert text { | 
|         line-height: 50rpx; | 
|     } | 
| </style> |