uni-app下拉刷新、上拉加载更多实现

r囧r小猫 2021-12-05 05:55 1230阅读 0赞

## 下拉刷新 ##

> [下拉刷新文档][Link 1]  
> 在 `js` 中定义 `onPullDownRefresh` 处理函数（和`onLoad`等生命周期函数同级），监听该页面用户下拉刷新事件。  
> 需要在 `pages.json` 里，找到的当前页面的`pages`节点，并在 `style` 选项中开启 `enablePullDownRefresh:true`。  
> 当处理完数据刷新后，`uni.stopPullDownRefresh` 可以停止当前页面的下拉刷新。

实例

pages.json
    
    {
        "pages": [
            {
                "path": "pages/index/index",
                "style": {
                    "navigationBarTitleText": "标题名称",
    				// App 和 小程序都开启下拉刷新
                    "enablePullDownRefresh": true
                }
            }
        ],
        "globalStyle": {
            "navigationBarTextStyle": "white",
            "navigationBarBackgroundColor": "#0faeff",
            "backgroundColor": "#fbf9fe"
        }
    }
    
    
    index.vue
    // 仅做示例，实际开发中延时根据需求来使用。
    export default {
        data: {
            text: 'uni-app'
        },
        onLoad: function (options) {
            setTimeout(function () {
                console.log('start pulldown');
            }, 1000);
            uni.startPullDownRefresh();
        },
        onPullDownRefresh() {
            console.log('refresh');
            setTimeout(function () {
                uni.stopPullDownRefresh();
            }, 1000);
        }
    }

## 上拉加载 ##

*  导入官方的一个上拉加载自定义组件

在 components 目录下（和 page 目录同级）新建一个 uni-load-more 文件夹，
    然后创建一个文件 uni-load-more.vue
    
    uni-load-more.vue 完整文件如下：
    
    <template>
    	<view class="uni-load-more">
    		<view v-show="status === 'loading' && showIcon" class="uni-load-more__img">
    			<view class="load1">
    				<view :style="{background:color}" />
    				<view :style="{background:color}" />
    				<view :style="{background:color}" />
    				<view :style="{background:color}" />
    			</view>
    			<view class="load2">
    				<view :style="{background:color}" />
    				<view :style="{background:color}" />
    				<view :style="{background:color}" />
    				<view :style="{background:color}" />
    			</view>
    			<view class="load3">
    				<view :style="{background:color}" />
    				<view :style="{background:color}" />
    				<view :style="{background:color}" />
    				<view :style="{background:color}" />
    			</view>
    		</view>
    		<text :style="{color:color}" class="uni-load-more__text">{
       { status === 'more' ? contentText.contentdown : (status === 'loading' ? contentText.contentrefresh : contentText.contentnomore) }}</text>
    	</view>
    </template>
    
    <script>
    	export default {
    		name: 'UniLoadMore',
    		props: {
    			status: {
    				// 上拉的状态：more-loading前；loading-loading中；noMore-没有更多了
    				type: String,
    				default: 'more'
    			},
    			showIcon: {
    				type: Boolean,
    				default: true
    			},
    			color: {
    				type: String,
    				default: '#777777'
    			},
    			contentText: {
    				type: Object,
    				default () {
    					return {
    						contentdown: '上拉显示更多',
    						contentrefresh: '正在加载...',
    						contentnomore: '没有更多数据了'
    					}
    				}
    			}
    		},
    		data() {
    			return {}
    		}
    	}
    </script>
    
    <style>
    	@charset "UTF-8";
    
    	.uni-load-more {
    		display: flex;
    		flex-direction: row;
    		height: 80upx;
    		align-items: center;
    		justify-content: center
    	}
    
    	.uni-load-more__text {
    		font-size: 28upx;
    		color: #999
    	}
    
    	.uni-load-more__img {
    		height: 24px;
    		width: 24px;
    		margin-right: 10px
    	}
    
    	.uni-load-more__img>view {
    		position: absolute
    	}
    
    	.uni-load-more__img>view view {
    		width: 6px;
    		height: 2px;
    		border-top-left-radius: 1px;
    		border-bottom-left-radius: 1px;
    		background: #999;
    		position: absolute;
    		opacity: .2;
    		transform-origin: 50%;
    		animation: load 1.56s ease infinite
    	}
    
    	.uni-load-more__img>view view:nth-child(1) {
    		transform: rotate(90deg);
    		top: 2px;
    		left: 9px
    	}
    
    	.uni-load-more__img>view view:nth-child(2) {
    		transform: rotate(180deg);
    		top: 11px;
    		right: 0
    	}
    
    	.uni-load-more__img>view view:nth-child(3) {
    		transform: rotate(270deg);
    		bottom: 2px;
    		left: 9px
    	}
    
    	.uni-load-more__img>view view:nth-child(4) {
    		top: 11px;
    		left: 0
    	}
    
    	.load1,
    	.load2,
    	.load3 {
    		height: 24px;
    		width: 24px
    	}
    
    	.load2 {
    		transform: rotate(30deg)
    	}
    
    	.load3 {
    		transform: rotate(60deg)
    	}
    
    	.load1 view:nth-child(1) {
    		animation-delay: 0s
    	}
    
    	.load2 view:nth-child(1) {
    		animation-delay: .13s
    	}
    
    	.load3 view:nth-child(1) {
    		animation-delay: .26s
    	}
    
    	.load1 view:nth-child(2) {
    		animation-delay: .39s
    	}
    
    	.load2 view:nth-child(2) {
    		animation-delay: .52s
    	}
    
    	.load3 view:nth-child(2) {
    		animation-delay: .65s
    	}
    
    	.load1 view:nth-child(3) {
    		animation-delay: .78s
    	}
    
    	.load2 view:nth-child(3) {
    		animation-delay: .91s
    	}
    
    	.load3 view:nth-child(3) {
    		animation-delay: 1.04s
    	}
    
    	.load1 view:nth-child(4) {
    		animation-delay: 1.17s
    	}
    
    	.load2 view:nth-child(4) {
    		animation-delay: 1.3s
    	}
    
    	.load3 view:nth-child(4) {
    		animation-delay: 1.43s
    	}
    
    	@-webkit-keyframes load {
    		0% {
    			opacity: 1
    		}
    
    		100% {
    			opacity: .2
    		}
    	}
    </style>

*  导入自定义的上拉加载组件，监听上拉加载，修改上拉加载的状态

完整的使用例子如下：
    
    <template>
    	<view>
    		<view>
    			<block v-for="(item , index) in list_array" :key="index">
    				<view>{
       { item }}</view>
    			</block>
    		</view>
    		
    		<view>
    			<uni-load-more :status="status"  :content-text="contentText" color="#007aff"  />
    		</view>
    	</view>
    </template>
    
    <script>
    	import uniLoadMore from '@/components/uni-load-more/uni-load-more.vue'
    
    	export default {
    		data() {
    			return {
    				list_array: ['1', '2', '3', '4', '5', '6', '7', '8', '9', '10', '11', '12', '13', '14', '15', '16', '17', '18',
    					'19',
    					'20','1', '2', '3', '4', '5', '6', '7', '8', '9', '10', '11', '12', '13', '14', '15'
    				],
    				status: 'more',
    				statusTypes: [{
    					value: 'more',
    					text: '加载前'
    				}, {
    					value: 'loading',
    					text: '加载中'
    				}, {
    					value: 'noMore',
    					text: '没有更多'
    				}],
    				contentText: {
    					contentdown: '查看更多',
    					contentrefresh: '加载中',
    					contentnomore: '没有更多'
    				}
    			}
    		},
    		components: {
    			uniLoadMore
    		},
    		onLoad: function(options) {
    			setTimeout(function() {
    				console.log('start pulldown');
    			}, 1000);
    			uni.startPullDownRefresh();
    		},
    		// 下拉刷新
    		onPullDownRefresh() {
    			console.log('refresh');
    			setTimeout(function() {
    				uni.stopPullDownRefresh();
    			}, 1000);
    		},
    		// 上拉加载
    		onReachBottom() {
    			let _self = this
    			this.status = 'loading'
    			uni.showNavigationBarLoading()
    			
    			console.log('reach');
    			setTimeout(function() {
    				for (var i = 0; i < 10; i++) {
    					_self.list_array.push("000" + i)
    				}
    				_self.status = 'more'
    				uni.hideNavigationBarLoading()
    			}, 2000);
    		},
    		methods: {
    
    		}
    	}
    </script>
    
    <style>
    	page {
    		display: flex;
    		flex-direction: column;
    		box-sizing: border-box;
    		background-color: #fff
    	}
    
    	view {
    		font-size: 28upx;
    		line-height: inherit
    	}
    
    	.example {
    		padding: 0 30upx 30upx
    	}
    
    	.example-title {
    		font-size: 32upx;
    		line-height: 32upx;
    		color: #777;
    		margin: 40upx 25upx;
    		position: relative
    	}
    
    	.example .example-title {
    		margin: 40upx 0
    	}
    
    	.example-body {
    		padding: 0 40upx
    	}
    
    	uni-radio-group uni-label {
    		padding: 0;
    	}
    
    	.uni-list-item__container {
    		padding: 24upx 30upx;
    		width: 100%;
    		box-sizing: border-box;
    		flex: 1;
    		position: relative;
    		display: flex;
    		flex-direction: row;
    		justify-content: space-between;
    		align-items: center;
    	}
    
    	.uni-list-item__container:after {
    		position: absolute;
    		z-index: 3;
    		right: 0;
    		bottom: 0;
    		left: 30upx;
    		height: 1px;
    		content: '';
    		-webkit-transform: scaleY(.5);
    		transform: scaleY(.5);
    		background-color: #c8c7cc;
    	}
    </style>

[Link 1]: https://uniapp.dcloud.io/collocation/pages?id=app-pulltorefresh