| <template> | |
| 	<view class="u-count-down"> | |
| 		<slot> | |
| 			<text class="u-count-down__text">{{ formattedTime }}</text> | |
| 		</slot> | |
| 	</view> | |
| </template> | |
| 
 | |
| <script> | |
| 	import props from './props.js'; | |
| 	import { | |
| 		isSameSecond, | |
| 		parseFormat, | |
| 		parseTimeData | |
| 	} from './utils'; | |
| 	/** | |
| 	 * u-count-down 倒计时 | |
| 	 * @description 该组件一般使用于某个活动的截止时间上,通过数字的变化,给用户明确的时间感受,提示用户进行某一个行为操作。 | |
| 	 * @tutorial https://uviewui.com/components/countDown.html | |
| 	 * @property {String | Number}	time		倒计时时长,单位ms (默认 0 ) | |
| 	 * @property {String}			format		时间格式,DD-日,HH-时,mm-分,ss-秒,SSS-毫秒  (默认 'HH:mm:ss' ) | |
| 	 * @property {Boolean}			autoStart	是否自动开始倒计时 (默认 true ) | |
| 	 * @property {Boolean}			millisecond	是否展示毫秒倒计时 (默认 false ) | |
| 	 * @event {Function} finish 倒计时结束时触发  | |
| 	 * @event {Function} change 倒计时变化时触发  | |
| 	 * @event {Function} start	开始倒计时 | |
| 	 * @event {Function} pause	暂停倒计时  | |
| 	 * @event {Function} reset	重设倒计时,若 auto-start 为 true,重设后会自动开始倒计时  | |
| 	 * @example <u-count-down :time="time"></u-count-down> | |
| 	 */ | |
| 	export default { | |
| 		name: 'u-count-down', | |
| 		mixins: [uni.$u.mpMixin, uni.$u.mixin, props], | |
| 		data() { | |
| 			return { | |
| 				timer: null, | |
| 				// 各单位(天,时,分等)剩余时间 | |
| 				timeData: parseTimeData(0), | |
| 				// 格式化后的时间,如"03:23:21" | |
| 				formattedTime: '0', | |
| 				// 倒计时是否正在进行中 | |
| 				runing: false, | |
| 				endTime: 0, // 结束的毫秒时间戳 | |
| 				remainTime: 0, // 剩余的毫秒时间 | |
| 			} | |
| 		}, | |
| 		watch: { | |
| 			time(n) { | |
| 				this.reset() | |
| 			} | |
| 		}, | |
| 		mounted() { | |
| 			this.init() | |
| 		}, | |
| 		methods: { | |
| 			init() { | |
| 				this.reset() | |
| 			}, | |
| 			// 开始倒计时 | |
| 			start() { | |
| 				if (this.runing) return | |
| 				// 标识为进行中 | |
| 				this.runing = true | |
| 				// 结束时间戳 = 此刻时间戳 + 剩余的时间 | |
| 				this.endTime = Date.now() + this.remainTime | |
| 				this.toTick() | |
| 			}, | |
| 			// 根据是否展示毫秒,执行不同操作函数 | |
| 			toTick() { | |
| 				if (this.millisecond) { | |
| 					this.microTick() | |
| 				} else { | |
| 					this.macroTick() | |
| 				} | |
| 			}, | |
| 			macroTick() { | |
| 				this.clearTimeout() | |
| 				// 每隔一定时间,更新一遍定时器的值 | |
| 				// 同时此定时器的作用也能带来毫秒级的更新 | |
| 				this.timer = setTimeout(() => { | |
| 					// 获取剩余时间 | |
| 					const remain = this.getRemainTime() | |
| 					// 重设剩余时间 | |
| 					if (!isSameSecond(remain, this.remainTime) || remain === 0) { | |
| 						this.setRemainTime(remain) | |
| 					} | |
| 					// 如果剩余时间不为0,则继续检查更新倒计时 | |
| 					if (this.remainTime !== 0) { | |
| 						this.macroTick() | |
| 					} | |
| 				}, 30) | |
| 			}, | |
| 			microTick() { | |
| 				this.clearTimeout() | |
| 				this.timer = setTimeout(() => { | |
| 					this.setRemainTime(this.getRemainTime()) | |
| 					if (this.remainTime !== 0) { | |
| 						this.microTick() | |
| 					} | |
| 				}, 50) | |
| 			}, | |
| 			// 获取剩余的时间 | |
| 			getRemainTime() { | |
| 				// 取最大值,防止出现小于0的剩余时间值 | |
| 				return Math.max(this.endTime - Date.now(), 0) | |
| 			}, | |
| 			// 设置剩余的时间 | |
| 			setRemainTime(remain) { | |
| 				this.remainTime = remain | |
| 				// 根据剩余的毫秒时间,得出该有天,小时,分钟等的值,返回一个对象 | |
| 				const timeData = parseTimeData(remain) | |
| 				this.$emit('change', timeData) | |
| 				// 得出格式化后的时间 | |
| 				this.formattedTime = parseFormat(this.format, timeData) | |
| 				// 如果时间已到,停止倒计时 | |
| 				if (remain <= 0) { | |
| 					this.pause() | |
| 					this.$emit('finish') | |
| 				} | |
| 			}, | |
| 			// 重置倒计时 | |
| 			reset() { | |
| 				this.pause() | |
| 				this.remainTime = this.time | |
| 				this.setRemainTime(this.remainTime) | |
| 				if (this.autoStart) { | |
| 					this.start() | |
| 				} | |
| 			}, | |
| 			// 暂停倒计时 | |
| 			pause() { | |
| 				this.runing = false; | |
| 				this.clearTimeout() | |
| 			}, | |
| 			// 清空定时器 | |
| 			clearTimeout() { | |
| 				clearTimeout(this.timer) | |
| 				this.timer = null | |
| 			} | |
| 		}, | |
| 		beforeDestroy() { | |
| 			this.clearTimeout() | |
| 		} | |
| 	} | |
| </script> | |
| 
 | |
| <style | |
| 	lang="scss" | |
| 	scoped | |
| > | |
| 	@import "../../libs/css/components.scss"; | |
| 	$u-count-down-text-color:$u-content-color !default; | |
| 	$u-count-down-text-font-size:15px !default; | |
| 	$u-count-down-text-line-height:22px !default; | |
| 
 | |
| 	.u-count-down { | |
| 		&__text { | |
| 			color: $u-count-down-text-color; | |
| 			font-size: $u-count-down-text-font-size; | |
| 			line-height: $u-count-down-text-line-height; | |
| 		} | |
| 	} | |
| </style>
 |