uniProject/components/kaoshixuzhi/examCountDown.vue

<template>
	<view class="exam-count-down-content">
		<view v-if="data.status === 'before'">
			<view class="exam-count-down-timer">{{formatTime}} </view>
		</view>
	</view>
</template>

<script setup>
	import {
		reactive,
		onUnmounted,
		computed,
		watch
	} from 'vue';

	const STATUS = {
		init: null,
		moreThenAnHour: 'more',
		before: 'before', // 等待参加
		after: 'after',
	};
	const props = defineProps({
		count: {
			type: Number,
			default: 10
		}
	})

	const Emits = defineEmits(['time-end'])

	const data = reactive({
		curCount: 0,
		status: STATUS.init,
		timer: null
	})

	const formatTime = computed(() => {
		if (data.curCount > 3600) {
			return '';
		}
		const minute = (Math.floor(data.curCount / 60)).toString().padStart(2, '0');
		const second = (Math.floor(data.curCount % 60)).toString().padStart(2, '0');
		return `${minute}:${second}`;
	})

	watch(() => data.curCount, (newVal) => {
		if (newVal > 3600) {
			data.status = STATUS.moreThenAnHour;
		} else if (newVal <= 3600 && newVal > 0) {
			data.status = STATUS.before;
		} else {
			data.status = STATUS.after;
		}

	}, {
		immediate: true
	})

	// 执行组件 组件启动
	function init() {
		console.log('init')
		data.curCount = props.count;
		if (data.curCount > 0) {
			countDown(data.curCount);
		}
	}
	// 终止组件 恢复初始化
	function termination() {
		clearTimer();
		resetCurCount();
		resetCurStatus();
	}

	function resetCurCount() {
		curCount = 0;
	}

	function resetCurStatus() {
		data.status = STATUS.init;
	}

	function clearTimer() {
		clearInterval(data.timer);
		data.timer = null;
	}
	// 倒计时业务执行
	function countDown(TIME_COUNT) {
		// 参数非数字 异常禁止执行
		if (typeof TIME_COUNT !== 'number') {
			return false;
		}
		// 参数小于等于0 不需要倒计时
		if (TIME_COUNT <= 0) {
			return false;
		}
		// 执行业务
		if (!data.timer) {
			data.timer = setInterval(() => {
				// 倒计时存在 执行倒计时业务
				if (data.curCount > 0) {
					data.curCount--;
					if (data.curCount <= 0) {
						Emits('time-end', true)
						data.clearTimer();
					}
				}
			}, 1000);
		}
	}
	onUnmounted(() => {
		clearTimer()
	})
	
	defineExpose({
		init,termination
	})
</script>

<style>

</style>