双列商品分类页面——uview+uniapp实现(单向联动+双向联动)

比眉伴天荒 2021-07-25 13:39 2887阅读 2赞

一个电商的app，商品的展示是必不可少的，联动分类展示是很常见的：

## 单向联动功能 ##

实现效果：

1.  左侧是分类列表，有很多分类，可以滑动并点击
2.  右侧是该分类下的商品列表
3.  仅支持左侧点击后右侧内容改变，为单向联动展示  
    ![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3llaGFvY2hlbmc1MjA_size_16_color_FFFFFF_t_70]

## 单向联动代码 ##

<view class="u-menu-wrap">
    	<scroll-view scroll-y scroll-with-animation class="u-tab-view menu-scroll-view" :scroll-top="scrollTop">
    		<view v-for="(item,index) in tabbar" :key="index" class="u-tab-item" :class="[current==index ? 'u-tab-item-active' : '']"
    		 :data-current="index" @tap.stop="swichMenu(index)">
    			<text class="u-line-1">{ { item.name}}</text>
    		</view>
    	</scroll-view>
    	<block v-for="(item,index) in tabbar" :key="index">
    		<scroll-view scroll-y class="right-box" v-if="current==index">
    			<view class="page-view">
    				<view class="class-item">
    					<view class="item-title">
    						<text>{ { item.name}}</text>
    					</view>
    					<view class="item-container">
    						<view class="thumb-box" v-for="(item1, index1) in item.foods" :key="index1">
    							<image class="item-menu-image" :src="item1.icon" mode=""></image>
    							<view class="item-menu-name">{ { item1.name}}</view>
    						</view>
    					</view>
    				</view>
    			</view>
    		</scroll-view>
    	</block>
    </view>
    <script>
    	import classifyData from "@/common/classify.data.js";//是本地模拟的数据
    	export default { 
    		data() { 
    			return { 
    				tabbar: classifyData,
    				scrollTop: 0, //tab标题的滚动条位置
    				current: 0, // 预设当前项的值
    				menuHeight: 0, // 左边菜单的高度
    				menuItemHeight: 0, // 左边菜单item的高度
    			}
    		},
    		methods: { 
    			// 点击左边的栏目切换
    			async swichMenu(index) { 
    				if(index == this.current) return ;
    				this.current = index;
    				// 如果为0，意味着尚未初始化
    				if(this.menuHeight == 0 || this.menuItemHeight == 0) { 
    					await this.getElRect('menu-scroll-view', 'menuHeight');
    					await this.getElRect('u-tab-item', 'menuItemHeight');
    				}
    				// 将菜单菜单活动item垂直居中
    				this.scrollTop = index * this.menuItemHeight + this.menuItemHeight / 2 - this.menuHeight / 2;
    			},
    			// 获取一个目标元素的高度
    			getElRect(elClass, dataVal) { 
    				new Promise((resolve, reject) => { 
    					const query = uni.createSelectorQuery().in(this);
    					query.select('.' + elClass).fields({ size: true},res => { 
    						// 如果节点尚未生成，res值为null，循环调用执行
    						if(!res) { 
    							setTimeout(() => { 
    								this.getElRect(elClass);
    							}, 10);
    							return ;
    						}
    						this[dataVal] = res.height;
    					}).exec();
    				})
    			}
    		}
    	}
    </script>
    
    <style lang="scss" scoped>
    	.u-wrap { 
    		height: calc(100vh);
    		/* #ifdef H5 */
    		height: calc(100vh - var(--window-top));
    		/* #endif */
    		display: flex;
    		flex-direction: column;
    	}
    
    	.u-search-box { 
    		padding: 18rpx 30rpx;
    	}
    
    	.u-menu-wrap { 
    		flex: 1;
    		display: flex;
    		overflow: hidden;
    	}
    
    	.u-search-inner { 
    		background-color: rgb(234, 234, 234);
    		border-radius: 100rpx;
    		display: flex;
    		align-items: center;
    		padding: 10rpx 16rpx;
    	}
    
    	.u-search-text { 
    		font-size: 26rpx;
    		color: $u-tips-color;
    		margin-left: 10rpx;
    	}
    
    	.u-tab-view { 
    		width: 200rpx;
    		height: 100%;
    	}
    
    	.u-tab-item { 
    		height: 110rpx;
    		background: #f6f6f6;
    		box-sizing: border-box;
    		display: flex;
    		align-items: center;
    		justify-content: center;
    		font-size: 26rpx;
    		color: #444;
    		font-weight: 400;
    		line-height: 1;
    	}
    	
    	.u-tab-item-active { 
    		position: relative;
    		color: #000;
    		font-size: 30rpx;
    		font-weight: 600;
    		background: #fff;
    	}
    	
    	.u-tab-item-active::before { 
    		content: "";
    		position: absolute;
    		border-left: 4px solid $u-type-primary;
    		height: 32rpx;
    		left: 0;
    		top: 39rpx;
    	}
    
    	.u-tab-view { 
    		height: 100%;
    	}
    	
    	.right-box { 
    		background-color: rgb(250, 250, 250);
    	}
    	
    	.page-view { 
    		padding: 16rpx;
    	}
    	
    	.class-item { 
    		margin-bottom: 30rpx;
    		background-color: #fff;
    		padding: 16rpx;
    		border-radius: 8rpx;
    	}
    	
    	.item-title { 
    		font-size: 26rpx;
    		color: $u-main-color;
    		font-weight: bold;
    	}
    	
    	.item-menu-name { 
    		font-weight: normal;
    		font-size: 24rpx;
    		color: $u-main-color;
    	}
    	
    	.item-container { 
    		display: flex;
    		flex-wrap: wrap;
    	}
    	
    	.thumb-box { 
    		width: 33.333333%;
    		display: flex;
    		align-items: center;
    		justify-content: center;
    		flex-direction: column;
    		margin-top: 20rpx;
    	}
    	
    	.item-menu-image { 
    		width: 120rpx;
    		height: 120rpx;
    	}
    </style>

## 双向联动 ##

实现效果：

1.  左侧是分类列表，有很多分类，可以滑动并点击
2.  右侧是该分类下的商品列表
3.  左侧点击时右侧展示对应分类的商品，右侧支持滑动，滑动时左侧分类也会相应改变

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3llaGFvY2hlbmc1MjA_size_16_color_FFFFFF_t_70 1]

## 双向联动代码 ##

<view class="u-menu-wrap">
    	<scroll-view scroll-y scroll-with-animation class="u-tab-view menu-scroll-view" :scroll-top="scrollTop"
    	 :scroll-into-view="itemId">
    		<view v-for="(item,index) in tabbar" :key="index" class="u-tab-item" :class="[current == index ? 'u-tab-item-active' : '']"
    		 @tap.stop="swichMenu(index)">
    			<text class="u-line-1">{ { item.name}}</text>
    		</view>
    	</scroll-view>
    	<scroll-view :scroll-top="scrollRightTop" scroll-y scroll-with-animation class="right-box" @scroll="rightScroll">
    		<view class="page-view">
    			<view class="class-item" :id="'item' + index" v-for="(item , index) in tabbar" :key="index">
    				<view class="item-title">
    					<text>{ { item.name}}</text>
    				</view>
    				<view class="item-container">
    					<view class="thumb-box" v-for="(item1, index1) in item.foods" :key="index1">
    						<image class="item-menu-image" :src="item1.icon" mode=""></image>
    						<view class="item-menu-name">{ { item1.name}}</view>
    					</view>
    				</view>
    			</view>
    		</view>
    	</scroll-view>
    </view>
    <script>
    	import classifyData from '@/common/classify.data.js';
    	export default { 
    		data() { 
    			return { 
    				scrollTop: 0, //tab标题的滚动条位置
    				oldScrollTop: 0,
    				current: 0, // 预设当前项的值
    				menuHeight: 0, // 左边菜单的高度
    				menuItemHeight: 0, // 左边菜单item的高度
    				itemId: '', // 栏目右边scroll-view用于滚动的id
    				tabbar: classifyData,
    				menuItemPos: [],
    				arr: [],
    				scrollRightTop: 0, // 右边栏目scroll-view的滚动条高度
    				timer: null, // 定时器
    				
    			}
    		},
    		onReady() { 
    			this.getMenuItemTop()
    		},
    		methods: { 
    			// 点击左边的栏目切换
    			async swichMenu(index) { 
    				if(this.arr.length == 0) { 
    					await this.getMenuItemTop();
    				}
    				if (index == this.current) return;
    				this.scrollRightTop = this.oldScrollTop;
    				this.$nextTick(function(){ 
    					this.scrollRightTop = this.arr[index];
    					this.current = index;
    					this.leftMenuStatus(index);
    				})
    			},
    			// 获取一个目标元素的高度
    			getElRect(elClass, dataVal) { 
    				new Promise((resolve, reject) => { 
    					const query = uni.createSelectorQuery().in(this);
    					query.select('.' + elClass).fields({ 
    						size: true
    					}, res => { 
    						// 如果节点尚未生成，res值为null，循环调用执行
    						if (!res) { 
    							setTimeout(() => { 
    								this.getElRect(elClass);
    							}, 10);
    							return;
    						}
    						this[dataVal] = res.height;
    						resolve();
    					}).exec();
    				})
    			},
    			// 观测元素相交状态
    			async observer() { 
    				this.tabbar.map((val, index) => { 
    					let observer = uni.createIntersectionObserver(this);
    					// 检测右边scroll-view的id为itemxx的元素与right-box的相交状态
    					// 如果跟.right-box底部相交，就动态设置左边栏目的活动状态
    					observer.relativeTo('.right-box', { 
    						top: 0
    					}).observe('#item' + index, res => { 
    						if (res.intersectionRatio > 0) { 
    							let id = res.id.substring(4);
    							this.leftMenuStatus(id);
    						}
    					})
    				})
    			},
    			// 设置左边菜单的滚动状态
    			async leftMenuStatus(index) { 
    				this.current = index;
    				// 如果为0，意味着尚未初始化
    				if (this.menuHeight == 0 || this.menuItemHeight == 0) { 
    					await this.getElRect('menu-scroll-view', 'menuHeight');
    					await this.getElRect('u-tab-item', 'menuItemHeight');
    				}
    				// 将菜单活动item垂直居中
    				this.scrollTop = index * this.menuItemHeight + this.menuItemHeight / 2 - this.menuHeight / 2;
    			},
    			// 获取右边菜单每个item到顶部的距离
    			getMenuItemTop() { 
    				new Promise(resolve => { 
    					let selectorQuery = uni.createSelectorQuery();
    					selectorQuery.selectAll('.class-item').boundingClientRect((rects) => { 
    						// 如果节点尚未生成，rects值为[](因为用selectAll，所以返回的是数组)，循环调用执行
    						if(!rects.length) { 
    							setTimeout(() => { 
    								this.getMenuItemTop();
    							}, 10);
    							return ;
    						}
    						rects.forEach((rect) => { 
    							// 这里减去rects[0].top，是因为第一项顶部可能不是贴到导航栏(比如有个搜索框的情况)
    							this.arr.push(rect.top - rects[0].top);
    							resolve();
    						})
    					}).exec()
    				})
    			},
    			// 右边菜单滚动
    			async rightScroll(e) { 
    				this.oldScrollTop = e.detail.scrollTop;
    				if(this.arr.length == 0) { 
    					await this.getMenuItemTop();
    				}
    				if(this.timer) return ;
    				if(!this.menuHeight) { 
    					await this.getElRect('menu-scroll-view', 'menuHeight');
    				}
    				setTimeout(() => {  // 节流
    					this.timer = null;
    					// scrollHeight为右边菜单垂直中点位置
    					let scrollHeight = e.detail.scrollTop + this.menuHeight / 2;
    					for (let i = 0; i < this.arr.length; i++) { 
    						let height1 = this.arr[i];
    						let height2 = this.arr[i + 1];
    						// 如果不存在height2，意味着数据循环已经到了最后一个，设置左边菜单为最后一项即可
    						if (!height2 || scrollHeight >= height1 && scrollHeight < height2) { 
    							this.leftMenuStatus(i);
    							return ;
    						}
    					}
    				}, 10)
    			}
    		}
    	}
    </script>
    
    <style lang="scss" scoped>
    	.u-wrap { 
    		height: calc(100vh);
    		/* #ifdef H5 */
    		height: calc(100vh - var(--window-top));
    		/* #endif */
    		display: flex;
    		flex-direction: column;
    	}
    
    	.u-search-box { 
    		padding: 18rpx 30rpx;
    	}
    
    	.u-menu-wrap { 
    		flex: 1;
    		display: flex;
    		overflow: hidden;
    	}
    
    	.u-search-inner { 
    		background-color: rgb(234, 234, 234);
    		border-radius: 100rpx;
    		display: flex;
    		align-items: center;
    		padding: 10rpx 16rpx;
    	}
    
    	.u-search-text { 
    		font-size: 26rpx;
    		color: $u-tips-color;
    		margin-left: 10rpx;
    	}
    
    	.u-tab-view { 
    		width: 200rpx;
    		height: 100%;
    	}
    
    	.u-tab-item { 
    		height: 110rpx;
    		background: #f6f6f6;
    		box-sizing: border-box;
    		display: flex;
    		align-items: center;
    		justify-content: center;
    		font-size: 26rpx;
    		color: #444;
    		font-weight: 400;
    		line-height: 1;
    	}
    
    	.u-tab-item-active { 
    		position: relative;
    		color: #000;
    		font-size: 30rpx;
    		font-weight: 600;
    		background: #fff;
    	}
    
    	.u-tab-item-active::before { 
    		content: "";
    		position: absolute;
    		border-left: 4px solid $u-type-primary;
    		height: 32rpx;
    		left: 0;
    		top: 39rpx;
    	}
    
    	.u-tab-view { 
    		height: 100%;
    	}
    
    	.right-box { 
    		background-color: rgb(250, 250, 250);
    	}
    
    	.page-view { 
    		padding: 16rpx;
    	}
    
    	.class-item { 
    		margin-bottom: 30rpx;
    		background-color: #fff;
    		padding: 16rpx;
    		border-radius: 8rpx;
    	}
    
    	.class-item:last-child { 
    		min-height: 100vh;
    	}
    
    	.item-title { 
    		font-size: 26rpx;
    		color: $u-main-color;
    		font-weight: bold;
    	}
    
    	.item-menu-name { 
    		font-weight: normal;
    		font-size: 24rpx;
    		color: $u-main-color;
    	}
    
    	.item-container { 
    		display: flex;
    		flex-wrap: wrap;
    	}
    
    	.thumb-box { 
    		width: 33.333333%;
    		display: flex;
    		align-items: center;
    		justify-content: center;
    		flex-direction: column;
    		margin-top: 20rpx;
    	}
    
    	.item-menu-image { 
    		width: 120rpx;
    		height: 120rpx;
    	}
    </style>

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3llaGFvY2hlbmc1MjA_size_16_color_FFFFFF_t_70]: /images/20210725/867882935d1044368354160e8a226bbb.png
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