<template> 
 | 
    <view class="u-index-list"> 
 | 
        <!-- #ifdef APP-NVUE --> 
 | 
        <list 
 | 
            :scrollTop="scrollTop" 
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            enable-back-to-top 
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            :offset-accuracy="1" 
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            :style="{ 
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                maxHeight: $u.addUnit(scrollViewHeight) 
 | 
            }" 
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            @scroll="scrollHandler" 
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            ref="uList" 
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        > 
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            <cell 
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                v-if="$slots.header" 
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                ref="header" 
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            > 
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                <slot name="header" /> 
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            </cell> 
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            <slot /> 
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            <cell v-if="$slots.footer"> 
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                <slot name="footer" /> 
 | 
            </cell> 
 | 
        </list> 
 | 
        <!-- #endif --> 
 | 
        <!-- #ifndef APP-NVUE --> 
 | 
        <scroll-view 
 | 
            :scrollTop="scrollTop" 
 | 
            :scrollIntoView="scrollIntoView" 
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            :offset-accuracy="1" 
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            :style="{ 
 | 
                maxHeight: $u.addUnit(scrollViewHeight) 
 | 
            }" 
 | 
            scroll-y 
 | 
            @scroll="scrollHandler" 
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            ref="uList" 
 | 
        > 
 | 
            <view v-if="$slots.header"> 
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                <slot name="header" /> 
 | 
            </view> 
 | 
            <slot /> 
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            <view v-if="$slots.footer"> 
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                <slot name="footer" /> 
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            </view> 
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        </scroll-view> 
 | 
        <!-- #endif --> 
 | 
        <view 
 | 
            class="u-index-list__letter" 
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            ref="u-index-list__letter" 
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            :style="{ top: $u.addUnit(letterInfo.top || 100) }" 
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            @touchstart="touchStart" 
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            @touchmove.stop.prevent="touchMove" 
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            @touchend.stop.prevent="touchEnd" 
 | 
            @touchcancel.stop.prevent="touchEnd" 
 | 
        > 
 | 
            <view 
 | 
                class="u-index-list__letter__item" 
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                v-for="(item, index) in uIndexList" 
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                :key="index" 
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                :style="{ 
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                    backgroundColor: activeIndex === index ? activeColor : 'transparent' 
 | 
                }" 
 | 
            > 
 | 
                <text 
 | 
                    class="u-index-list__letter__item__index" 
 | 
                    :style="{color: activeIndex === index ? '#fff' : inactiveColor}" 
 | 
                >{{ item }}</text> 
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            </view> 
 | 
        </view> 
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        <u-transition 
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            mode="fade" 
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            :show="touching" 
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            :customStyle="{ 
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                position: 'fixed', 
 | 
                right: '50px', 
 | 
                top: $u.addUnit(indicatorTop), 
 | 
                zIndex: 2 
 | 
            }" 
 | 
        > 
 | 
            <view 
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                class="u-index-list__indicator" 
 | 
                :class="['u-index-list__indicator--show']" 
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                :style="{ 
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                    height: $u.addUnit(indicatorHeight), 
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                    width: $u.addUnit(indicatorHeight) 
 | 
                }" 
 | 
            > 
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                <text class="u-index-list__indicator__text">{{ uIndexList[activeIndex] }}</text> 
 | 
            </view> 
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        </u-transition> 
 | 
    </view> 
 | 
</template> 
 | 
  
 | 
<script> 
 | 
    const indexList = () => { 
 | 
        const indexList = []; 
 | 
        const charCodeOfA = 'A'.charCodeAt(0); 
 | 
        for (let i = 0; i < 26; i++) { 
 | 
            indexList.push(String.fromCharCode(charCodeOfA + i)); 
 | 
        } 
 | 
        return indexList; 
 | 
    } 
 | 
    import props from './props.js'; 
 | 
    // #ifdef APP-NVUE 
 | 
    // 由于weex为阿里的KPI业绩考核的产物,所以不支持百分比单位,这里需要通过dom查询组件的宽度 
 | 
    const dom = uni.requireNativePlugin('dom') 
 | 
    // #endif 
 | 
    /** 
 | 
     * IndexList 索引列表 
 | 
     * @description  通过折叠面板收纳内容区域 
 | 
     * @tutorial https://uviewui.com/components/indexList.html 
 | 
     * @property {String}            inactiveColor    右边锚点非激活的颜色 ( 默认 '#606266' ) 
 | 
     * @property {String}            activeColor        右边锚点激活的颜色 ( 默认 '#5677fc' ) 
 | 
     * @property {Array}            indexList        索引字符列表,数组形式 
 | 
     * @property {Boolean}            sticky            是否开启锚点自动吸顶 ( 默认 true ) 
 | 
     * @property {String | Number}    customNavHeight    自定义导航栏的高度 ( 默认 0 ) 
 | 
     * */  
 | 
    export default { 
 | 
        name: 'u-index-list', 
 | 
        mixins: [uni.$u.mpMixin, uni.$u.mixin, props], 
 | 
        // #ifdef MP-WEIXIN 
 | 
        // 将自定义节点设置成虚拟的,更加接近Vue组件的表现,能更好的使用flex属性 
 | 
        options: { 
 | 
            virtualHost: true 
 | 
        }, 
 | 
        // #endif 
 | 
        data() { 
 | 
            return { 
 | 
                // 当前正在被选中的字母索引 
 | 
                activeIndex: -1, 
 | 
                touchmoveIndex: 1, 
 | 
                // 索引字母的信息 
 | 
                letterInfo: { 
 | 
                    height: 0, 
 | 
                    itemHeight: 0, 
 | 
                    top: 0 
 | 
                }, 
 | 
                // 设置字母指示器的高度,后面为了让指示器跟随字母,并将尖角部分指向字母的中部,需要依赖此值 
 | 
                indicatorHeight: 50, 
 | 
                // 字母放大指示器的top值,为了让其指向当前激活的字母 
 | 
                // indicatorTop: 0 
 | 
                // 当前是否正在被触摸状态 
 | 
                touching: false, 
 | 
                // 滚动条顶部top值 
 | 
                scrollTop: 0, 
 | 
                // scroll-view的高度 
 | 
                scrollViewHeight: 0, 
 | 
                // 系统信息 
 | 
                sys: uni.$u.sys(), 
 | 
                scrolling: false, 
 | 
                scrollIntoView: '', 
 | 
            } 
 | 
        }, 
 | 
        computed: { 
 | 
            // 如果有传入外部的indexList锚点数组则使用,否则使用内部生成A-Z字母 
 | 
            uIndexList() { 
 | 
                return this.indexList.length ? this.indexList : indexList() 
 | 
            }, 
 | 
            // 字母放大指示器的top值,为了让其指向当前激活的字母 
 | 
            indicatorTop() { 
 | 
                const { 
 | 
                    top, 
 | 
                    itemHeight 
 | 
                } = this.letterInfo 
 | 
                return Math.floor(top + itemHeight * this.activeIndex + itemHeight / 2 - this.indicatorHeight / 2) 
 | 
            } 
 | 
        }, 
 | 
        watch: { 
 | 
            // 监听字母索引的变化,重新设置尺寸 
 | 
            uIndexList: { 
 | 
                immediate: true, 
 | 
                handler() { 
 | 
                    uni.$u.sleep().then(() => { 
 | 
                        this.setIndexListLetterInfo() 
 | 
                    }) 
 | 
                } 
 | 
            } 
 | 
        }, 
 | 
        created() { 
 | 
            this.children = [] 
 | 
            this.anchors = [] 
 | 
            this.init() 
 | 
        }, 
 | 
        mounted() { 
 | 
            this.setIndexListLetterInfo() 
 | 
        }, 
 | 
        methods: { 
 | 
            init() { 
 | 
                // 设置列表的高度为整个屏幕的高度 
 | 
                //减去this.customNavHeight,并将this.scrollViewHeight设置为maxHeight 
 | 
                //解决当u-index-list组件放在tabbar页面时,scroll-view内容较少时,还能滚动 
 | 
                this.scrollViewHeight = this.sys.windowHeight - this.customNavHeight 
 | 
            }, 
 | 
            // 索引列表被触摸 
 | 
            touchStart(e) { 
 | 
                // 获取触摸点信息 
 | 
                const touchStart = e.changedTouches[0] 
 | 
                if (!touchStart) return 
 | 
                this.touching = true 
 | 
                const { 
 | 
                    pageY 
 | 
                } = touchStart 
 | 
                // 根据当前触摸点的坐标,获取当前触摸的为第几个字母 
 | 
                const currentIndex = this.getIndexListLetter(pageY) 
 | 
                this.setValueForTouch(currentIndex) 
 | 
            }, 
 | 
            // 索引字母列表被触摸滑动中 
 | 
            touchMove(e) { 
 | 
                // 获取触摸点信息 
 | 
                let touchMove = e.changedTouches[0] 
 | 
                if (!touchMove) return; 
 | 
  
 | 
                // 滑动结束后迅速开始第二次滑动时候 touching 为 false 造成不显示 indicator 问题 
 | 
                if (!this.touching) { 
 | 
                    this.touching = true 
 | 
                } 
 | 
                const { 
 | 
                    pageY 
 | 
                } = touchMove 
 | 
                const currentIndex = this.getIndexListLetter(pageY) 
 | 
                this.setValueForTouch(currentIndex) 
 | 
            }, 
 | 
            // 触摸结束 
 | 
            touchEnd(e) { 
 | 
                // 延时一定时间后再隐藏指示器,为了让用户看的更直观,同时也是为了消除快速切换u-transition的show带来的影响 
 | 
                uni.$u.sleep(300).then(() => { 
 | 
                    this.touching = false 
 | 
                }) 
 | 
            }, 
 | 
            // 获取索引列表的尺寸以及单个字符的尺寸信息 
 | 
            getIndexListLetterRect() { 
 | 
                return new Promise(resolve => { 
 | 
                    // 延时一定时间,以获取dom尺寸 
 | 
                    // #ifndef APP-NVUE 
 | 
                    this.$uGetRect('.u-index-list__letter').then(size => { 
 | 
                        resolve(size) 
 | 
                    }) 
 | 
                    // #endif 
 | 
  
 | 
                    // #ifdef APP-NVUE 
 | 
                    const ref = this.$refs['u-index-list__letter'] 
 | 
                    dom.getComponentRect(ref, res => { 
 | 
                        resolve(res.size) 
 | 
                    }) 
 | 
                    // #endif 
 | 
                }) 
 | 
            }, 
 | 
            // 设置indexList索引的尺寸信息 
 | 
            setIndexListLetterInfo() { 
 | 
                this.getIndexListLetterRect().then(size => { 
 | 
                    const { 
 | 
                        height 
 | 
                    } = size 
 | 
                    const sys = uni.$u.sys() 
 | 
                    const windowHeight = sys.windowHeight 
 | 
                    let customNavHeight = 0 
 | 
                    // 消除各端导航栏非原生和原生导致的差异,让索引列表字母对屏幕垂直居中 
 | 
                    if (this.customNavHeight == 0) { 
 | 
                        // #ifdef H5 
 | 
                        customNavHeight = sys.windowTop 
 | 
                        // #endif 
 | 
                        // #ifndef H5 
 | 
                        // 在非H5中,为原生导航栏,其高度不算在windowHeight内,这里设置为负值,后面相加时变成减去其高度的一半 
 | 
                        customNavHeight = -(sys.statusBarHeight + 44) 
 | 
                        // #endif 
 | 
                    } else { 
 | 
                        customNavHeight = uni.$u.getPx(this.customNavHeight) 
 | 
                    } 
 | 
                    this.letterInfo = { 
 | 
                        height, 
 | 
                        // 为了让字母列表对屏幕绝对居中,让其对导航栏进行修正,也即往上偏移导航栏的一半高度 
 | 
                        top: (windowHeight - height) / 2 + customNavHeight / 2, 
 | 
                        itemHeight: Math.floor(height / this.uIndexList.length) 
 | 
                    } 
 | 
                }) 
 | 
            }, 
 | 
            // 获取当前被触摸的索引字母 
 | 
            getIndexListLetter(pageY) { 
 | 
                const { 
 | 
                    top, 
 | 
                    height, 
 | 
                    itemHeight 
 | 
                } = this.letterInfo 
 | 
                // 对H5的pageY进行修正,这是由于uni-app自作多情在H5中将触摸点的坐标跟H5的导航栏结合导致的问题 
 | 
                // #ifdef H5 
 | 
                pageY += uni.$u.sys().windowTop 
 | 
                // #endif 
 | 
                // 对第一和最后一个字母做边界处理,因为用户可能在字母列表上触摸到两端的尽头后依然继续滑动 
 | 
                if (pageY < top) { 
 | 
                    return 0 
 | 
                } else if (pageY >= top + height) { 
 | 
                    // 如果超出了,取最后一个字母 
 | 
                    return this.uIndexList.length - 1 
 | 
                } else { 
 | 
                    // 将触摸点的Y轴偏移值,减去索引字母的top值,除以每个字母的高度,即可得到当前触摸点落在哪个字母上 
 | 
                    return Math.floor((pageY - top) / itemHeight); 
 | 
                } 
 | 
            }, 
 | 
            // 设置各项由触摸而导致变化的值 
 | 
            setValueForTouch(currentIndex) { 
 | 
                // 如果偏移量太小,前后得出的会是同一个索引字母,为了防抖,进行返回 
 | 
                if (currentIndex === this.activeIndex) return 
 | 
                this.activeIndex = currentIndex 
 | 
                // #ifndef APP-NVUE || MP-WEIXIN 
 | 
                // 在非nvue中,由于anchor和item都在u-index-item中,所以需要对index-item进行偏移 
 | 
                this.scrollIntoView = `u-index-item-${this.uIndexList[currentIndex].charCodeAt(0)}` 
 | 
                // #endif 
 | 
                // #ifdef MP-WEIXIN 
 | 
                // 微信小程序下,scroll-view的scroll-into-view属性无法对slot中的内容的id生效,只能通过设置scrollTop的形式去移动滚动条 
 | 
                this.scrollTop = this.children[currentIndex].top 
 | 
                // #endif 
 | 
                // #ifdef APP-NVUE 
 | 
                // 在nvue中,由于cell和header为同级元素,所以实际是需要对header(anchor)进行偏移 
 | 
                const anchor = `u-index-anchor-${this.uIndexList[currentIndex]}` 
 | 
                dom.scrollToElement(this.anchors[currentIndex].$refs[anchor], { 
 | 
                    offset: 0, 
 | 
                    animated: false 
 | 
                }) 
 | 
                // #endif 
 | 
            }, 
 | 
            getHeaderRect() { 
 | 
                // 获取header slot的高度,因为list组件中获取元素的尺寸是没有top值的 
 | 
                return new Promise(resolve => { 
 | 
                    dom.getComponentRect(this.$refs.header, res => { 
 | 
                        resolve(res.size) 
 | 
                    }) 
 | 
                }) 
 | 
            }, 
 | 
            // scroll-view的滚动事件 
 | 
            async scrollHandler(e) { 
 | 
                if (this.touching || this.scrolling) return 
 | 
                // 每过一定时间取样一次,减少资源损耗以及可能带来的卡顿 
 | 
                this.scrolling = true 
 | 
                uni.$u.sleep(10).then(() => { 
 | 
                    this.scrolling = false 
 | 
                }) 
 | 
                let scrollTop = 0 
 | 
                const len = this.children.length 
 | 
                let children = this.children 
 | 
                const anchors = this.anchors 
 | 
                // #ifdef APP-NVUE 
 | 
                // nvue下获取的滚动条偏移为负数,需要转为正数 
 | 
                scrollTop = Math.abs(e.contentOffset.y) 
 | 
                // 获取header slot的尺寸信息 
 | 
                const header = await this.getHeaderRect() 
 | 
                // item的top值,在nvue下,模拟出的anchor的top,类似非nvue下的index-item的top 
 | 
                let top = header.height 
 | 
                // 由于list组件无法获取cell的top值,这里通过header slot和各个item之间的height,模拟出类似非nvue下的位置信息 
 | 
                children = this.children.map((item, index) => { 
 | 
                    const child = { 
 | 
                        height: item.height, 
 | 
                        top 
 | 
                    } 
 | 
                    // 进行累加,给下一个item提供计算依据 
 | 
                    top += item.height + anchors[index].height 
 | 
                    return child 
 | 
                }) 
 | 
                // #endif 
 | 
                // #ifndef APP-NVUE 
 | 
                // 非nvue通过detail获取滚动条位移 
 | 
                scrollTop = e.detail.scrollTop 
 | 
                // #endif 
 | 
                for (let i = 0; i < len; i++) { 
 | 
                    const item = children[i], 
 | 
                        nextItem = children[i + 1] 
 | 
                    // 如果滚动条高度小于第一个item的top值,此时无需设置任意字母为高亮 
 | 
                    if (scrollTop <= children[0].top || scrollTop >= children[len - 1].top + children[len - 
 | 
                            1].height) { 
 | 
                        this.activeIndex = -1 
 | 
                        break 
 | 
                    } else if (!nextItem) {  
 | 
                        // 当不存在下一个item时,意味着历遍到了最后一个 
 | 
                        this.activeIndex = len - 1 
 | 
                        break 
 | 
                    } else if (scrollTop > item.top && scrollTop < nextItem.top) { 
 | 
                        this.activeIndex = i 
 | 
                        break 
 | 
                    } 
 | 
                } 
 | 
            }, 
 | 
        }, 
 | 
    } 
 | 
</script> 
 | 
  
 | 
<style lang="scss" scoped> 
 | 
    @import "../../libs/css/components.scss"; 
 | 
  
 | 
    .u-index-list { 
 | 
  
 | 
        &__letter { 
 | 
            position: fixed; 
 | 
            right: 0; 
 | 
            text-align: center; 
 | 
            z-index: 3; 
 | 
            padding: 0 6px; 
 | 
  
 | 
            &__item { 
 | 
                width: 16px; 
 | 
                height: 16px; 
 | 
                border-radius: 100px; 
 | 
                margin: 1px 0; 
 | 
                @include flex; 
 | 
                align-items: center; 
 | 
                justify-content: center; 
 | 
  
 | 
                &--active { 
 | 
                    background-color: $u-primary; 
 | 
                } 
 | 
  
 | 
                &__index { 
 | 
                    font-size: 12px; 
 | 
                    text-align: center; 
 | 
                    line-height: 12px; 
 | 
                } 
 | 
            } 
 | 
        } 
 | 
  
 | 
        &__indicator { 
 | 
            width: 50px; 
 | 
            height: 50px; 
 | 
            border-radius: 100px 100px 0 100px; 
 | 
            text-align: center; 
 | 
            color: #ffffff; 
 | 
            background-color: #c9c9c9; 
 | 
            transform: rotate(-45deg); 
 | 
            @include flex; 
 | 
            justify-content: center; 
 | 
            align-items: center; 
 | 
  
 | 
            &__text { 
 | 
                font-size: 28px; 
 | 
                line-height: 28px; 
 | 
                font-weight: bold; 
 | 
                color: #fff; 
 | 
                transform: rotate(45deg); 
 | 
                text-align: center; 
 | 
            } 
 | 
        } 
 | 
    } 
 | 
</style> 
 |