app.vue里面写
onLaunch: function(launch) {
		let that = this
		// #ifdef APP-PLUS	
		uni.getSystemInfo({
			success(res) {
				console.log(res)
				console.log(res.platform) 
				console.log(res.version) 
				that.platform = res.platform
				that.version = res.version
				
			}
		});
		
		 
		if(this.platform == ‘android‘){
			this.$util.request({//获取轮播
				url: ‘/mobile/index.php?act=index&op=apk_version‘,
				method: ‘get‘,
				data: {},
			}).then((res)=> {
				 console.log(res)
				 if(res.error_code == 0 && res.datas.url != ""){
					console.log(res.datas.version,"版本号")
					if(res.datas.version != that.version){
						uni.showModal({
						    title: ‘版本更新‘,
						    content: ‘是否更新到最新版本‘+res.datas.version,
						    success:  (res2)=> {
						        if (res2.confirm) {
									// 下载最新的版本									
									console.log(res.datas.url,"下载链接")									
									that.doUpData(res.datas.url)						            
						        } else if (res2.cancel) {
						             
						        }
						    }
						});
					}			 
				 }
			})	
		}		
		if(this.platform == ‘ios‘){
			this.$util.request({//获取轮播
				url: ‘/mobile/index.php?act=index&op=ios_version‘,
				method: ‘get‘,
				data: {},
			}).then((res)=> {
				 
				 console.log(res,123456)
				 if(res.error_code == 0 && res.datas.url != ""){
					console.log(res.datas.version,"版本号")
					if(res.datas.version != that.version ){
						uni.showModal({
						    title: ‘版本更新‘,
						    content: ‘是否更新到最新版本‘+res.datas.version,
						    success:  (res2)=> {
						        if (res2.confirm) {
									// 下载最新的版本									
									console.log(res.datas.url,"下载链接")									
									that.doUpData(res.datas.url)						            
						        } else if (res2.cancel) {
						            
						        }
						    }
						});
					}			 
				 }
			})	
		}
		
		
		// #endif
		
		
	},