后台要配置一个ws://的域名

                uni.connectSocket({
                url: 'ws://120.25.249.130:8001/socketText/1'
            });

            uni.onSocketOpen(function(res) {
                socketOpen = true;
                for (var i = 0; i < socketMsgQueue.length; i++) {
                    sendSocketMessage(socketMsgQueue[i]);
                }
                socketMsgQueue = [];
            });
            uni.onSocketError(function(res) {
                console.log('WebSocket连接打开失败，请检查！');
            });

            function sendSocketMessage(msg) {
                if (socketOpen) {
                    uni.sendSocketMessage({
                        data: msg
                    });
                } else {
                    socketMsgQueue.push(msg);
                }
            }
            uni.onSocketMessage(function(res) {
                console.log('收到服务器内容：' + res.data);
            });