uniapp如何实现全局消息顶部通知栏效果？

可以下载这个插件

https://ext.dcloud.net.cn/plugin?name=uni-popup

记得import一下

<template>
	<view>
		<button style="background-color: #4cd964;" @click="toggleMessage('success')">成功</button>
		<button style="background-color: #dd524d;" @click="toggleMessage('error')">错误</button>
		<button style="background-color: #f0ad4e;" @click="toggleMessage('warn')">警告</button>
		<button style="background-color: #909399;" @click="toggleMessage('info')">信息</button>
		<!-- 消息提示 -->
		<uni-popup ref="popupMessage" type="message">
			<uni-popup-message :type="msgType" :message="message" :duration="700" />
		</uni-popup>
		<!-- 对话框 -->
		<uni-popup ref="popupDialog" type="dialog">
			<uni-popup-dialog :type="msgType" title="通知" content="欢迎使用 uni-popup!" :before-close="true" @confirm="dialogConfirm" @close="dialogClose" />
		</uni-popup>
	</view>
</template>
 
<script>
export default {
	data() {
		return {
			msgType: 'top',
			message: '这是一条成功消息提示'
		};
	},
	methods: {
		toggleMessage(type) {
			this.msgType = type;
			switch (type) {
				case 'success':
					this.message = '这是一条成功消息提示';
					break;
				case 'warn':
					this.message = '这是一条警告消息提示';
					break;
				case 'info':
					this.message = '这是一条消息提示';
					break;
				case 'error':
					this.message = '这是一条错误消息提示';
					break;
			}
			this.$refs.popupDialog.open();
		},
		dialogConfirm() {
			this.$refs.popupMessage.open();
			
			this.$refs['popupDialog'].close();
		},
		dialogClose() {
			this.msgType = 'info';
			this.message = '点击了对话框的取消按钮';
			this.$refs.popupMessage.open();
			
			this.$refs.popupDialog.close();
		}
	}
};
</script>