Dayu200与Hi3861 TCP通信（JS）

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• OH系统版本：OpenHarmony3.1Release
• IDE： 3.0.0.900
• 实现语言：JS

参考地址：​​Socket连接​​

TCP通信流程：

Initial TCP ————> Bind IP ————> Connect Target IP ————> Send/Receive

• 初始化IP相关配置：

- 引用模块： import socket from '@ohos.net.socket'
- 添加权限：ohos.permission.INTERNET、ohos.permission.GET_WIFI_INFO
- 创建对象：let tcp = socket.constructTCPSocketInstance();

• 绑定IP与端口号

bind(address: NetAddress, callback: AsyncCallback<void>): void
绑定IP地址和端口，端口可以指定或由系统随机分配。使用callback方法作为异步方法。
需要权限：ohos.permission.INTERNET
系统能力：SystemCapability.Communication.NetStack
示例：
let tcp = socket.constructTCPSocketInstance();
tcp.bind({address: '192.168.xx.xxx', port: xxxx, family: 1}, err => {
 if (err) {
 console.log('bind fail');
 return;
 }
 console.log('bind success');
})

• 连接目标IP

connect(options: TCPConnectOptions, callback: AsyncCallback<void>): void
连接到指定的IP地址和端口。使用callback方法作为异步方法。
需要权限：ohos.permission.INTERNET
系统能力：SystemCapability.Communication.NetStack
示例：
let tcp = socket.constructTCPSocketInstance();
tcp.connect({ address: {address: '192.168.xx.xxx', port: xxxx, family: 1} , timeout: 6000}, err => {
 if (err) {
 console.log('connect fail');
 return;
 }
 console.log('connect success');
})

• 发送/接收数据

//发送数据 
send(options: TCPSendOptions, callback: AsyncCallback<void>): void
通过TCPSocket连接发送数据。使用callback方式作为异步方法。
说明： connect方法调用成功后，才可调用此方法。
需要权限：ohos.permission.INTERNET
系统能力：SystemCapability.Communication.NetStack
示例：
 tcpSend()
 {
 tcp.send({
 data: this.app_msg,
 }, err => {
 if (err) {
 console.log('send fail');
 return;
 }
 });
 },
//接收数据 并解析数据为String
on(type: ‘message’, callback: Callback<{message: ArrayBuffer, remoteInfo: SocketRemoteInfo}>): void
订阅TCPSocket连接的接收消息事件。使用callback方式作为异步方法。
系统能力：SystemCapability.Communication.NetStack
tcp.on('message', value => {
 console.log("on message")
 let buffer = value.message
 let dataView = new DataView(buffer)
 let str = ""
 for (let i = 0;i < dataView.byteLength; ++i) {
 str += String.fromCharCode(dataView.getUint8(i))
 }
 console.log("on connect received:" + str)
 this.receive_data=str;
 prompt.showToast({
 message:str,
 duration:1000
 });
 });

按照上一节的流程，编写对应的JS程序即可。UI如下：

第一个按钮用于绑定IP，并设置订阅TCPSocket相关的订阅事件。

 tcpClient()
 {
 // 订阅TCPSocket相关的订阅事件
 tcp.on('message', value => {
 console.log("on message")
 let buffer = value.message
 let dataView = new DataView(buffer)
 let str = ""
 for (let i = 0;i < dataView.byteLength; ++i) {
 str += String.fromCharCode(dataView.getUint8(i))
 }
 console.log("on connect received:" + str)
 this.receive_data=str;
 prompt.showToast({
 message:str,
 duration:1000
 });
 });
 tcp.on('connect', () => {
 console.log("on connect")
 });
 tcp.on('close', () => {
 console.log("on close")
 });

 // 绑定IP地址和端口。
 let bindAddress = {
 address: wifi.getIpInfo().ipAddress,
 port: 1234,
 family: 1
 };
 tcp.bind(bindAddress, err => {
 if (err) {
 console.log('bind fail');
 return;
 }
 console.log('bind success');
 prompt.showToast({
 message:"bind success",
 })
 });
 },

第二个按钮用于连接Hi3861：

 tcpConnect()
 {
 prompt.showToast({
 message:'wifiAddr'+wifi.isConnected()+wifi.getIpInfo().ipAddress,
 });
// let promise = tcp.connect({ address: {address:'192.168.137.92', port: 8888, family: 1} , timeout: 6000});
// promise.then(() => {
// console.log('connect success')
// prompt.showToast({
// message:"connect success",
// });
// }).catch(err => {
// prompt.showToast({
// message:"connect fail",
// });
// console.log('connect fail');
// });
 tcp.connect({ address: {address: '192.168.137.92', port: 8888, family: 1} , timeout: 6000}, err => {
 if (err) {
 console.log('connect fail');
 prompt.showToast({
 message:"connect fail",
 });
 return;
 }
 console.log('connect success');
 prompt.showToast({
 message:"connect success",
 });
 })
 },

第三个按钮实现发送数据：

tcpSend()
 {
 tcp.send({
 data: this.app_msg,
 }, err => {
 if (err) {
 console.log('send fail');
 prompt.showToast({
 message:"send fail",
 });
 return;
 }
 prompt.showToast({
 message:"send successful"
 })
 });
 },

参考小熊派开发板TCP server案例。主要任务是开启wifi，获取周围wifi列表。

#define SELECT_WLAN_PORT "wlan0"
int WifiConnect(const char *ssid, const char *psk)
{
 WifiScanInfo *info = NULL;
 unsigned int size = WIFI_SCAN_HOTSPOT_LIMIT;
 static struct netif *g_lwip_netif = NULL;
 osDelay(200);
 printf("<--System Init-->\r\n");
 //初始化WIFI
 WiFiInit();
 //使能WIFI
 if (EnableWifi() != WIFI_SUCCESS)
 {
 printf("EnableWifi failed, error = %d\r\n", error);
 return -1;
 }
 //判断WIFI是否激活
 if (IsWifiActive() == 0)
 {
 printf("Wifi station is not actived.\r\n");
 return -1;
 }
 //分配空间，保存WiFi信息
 info = malloc(sizeof(WifiScanInfo) * WIFI_SCAN_HOTSPOT_LIMIT);
 if (info == NULL)
 {
 return -1;
 }
 //轮询查找WiFi列表
 do{
 //重置标志位
 ssid_count = 0;
 g_staScanSuccess = 0;
 //开始扫描
 Scan();
 //等待扫描结果
 WaitSacnResult();
 //获取扫描列表
 error = GetScanInfoList(info, &size);
 }while(g_staScanSuccess != 1);
 
 //连接指定的WiFi热点
 for(uint8_t i = 0; i < ssid_count; i++)
 {
 if (strcmp(ssid, info[i].ssid) == 0)
 {
 int result;

 printf("Select:%3d wireless, Waiting...\r\n", i+1);

 //拷贝要连接的热点信息
 WifiDeviceConfig select_ap_config = {0};
 strcpy(select_ap_config.ssid, info[i].ssid);
 strcpy(select_ap_config.preSharedKey, psk);
 select_ap_config.securityType = SELECT_WIFI_SECURITYTYPE;

 if (AddDeviceConfig(&select_ap_config, &result) == WIFI_SUCCESS)
 {
 if (ConnectTo(result) == WIFI_SUCCESS && WaitConnectResult() == 1)
 {
 printf("WiFi connect succeed!\r\n");
 g_lwip_netif = netifapi_netif_find(SELECT_WLAN_PORT);
 break;
 }
 }
 }

 if(i == ssid_count-1)
 {
 printf("ERROR: No wifi as expected\r\n");
 while(1) osDelay(100);
 }
 }
 //启动DHCP
 if (g_lwip_netif)
 {
 dhcp_start(g_lwip_netif);
 printf("begain to dhcp\r\n");
 }
 //等待DHCP
 for(;;)
 {
 if(dhcp_is_bound(g_lwip_netif) == ERR_OK)
 {
 printf("<-- DHCP state:OK -->\r\n");
 //打印获取到的IP信息
 netifapi_netif_common(g_lwip_netif, dhcp_clients_info_show, NULL);
 break;
 }
 printf("<-- DHCP state:Inprogress -->\r\n");
 osDelay(100);
 }
 osDelay(100);
 return 0;
}

连接指定wifi，创建socket server，监听指定IP 端口。

char *buf = "Hello! I'm BearPi-HM_Nano TCP Server!";
static void TCPServerTask(void)
{
 //服务端地址信息
 struct sockaddr_in server_sock;

 //客户端地址信息
 struct sockaddr_in client_sock;
 int sin_size;

 struct sockaddr_in *cli_addr;

 //连接Wifi
 WifiConnect("r1", "88888889");

 //创建socket
 if ((sock_fd = socket(AF_INET, SOCK_STREAM, 0)) == -1)
 {
 perror("socket is error\r\n");
 exit(1);
 }

 bzero(&server_sock, sizeof(server_sock));
 server_sock.sin_family = AF_INET;
 server_sock.sin_addr.s_addr = htonl(INADDR_ANY);
 server_sock.sin_port = htons(_PROT_);

 //调用bind函数绑定socket和地址
 if (bind(sock_fd, (struct sockaddr *)&server_sock, sizeof(struct sockaddr)) == -1)
 {
 perror("bind is error\r\n");
 exit(1);
 }

 //调用listen函数监听(指定port监听)
 if (listen(sock_fd, TCP_BACKLOG) == -1)
 {
 perror("listen is error\r\n");
 exit(1);
 }

 printf("start accept\n");

 //调用accept函数从队列中
 while (1)
 {
 sin_size = sizeof(struct sockaddr_in);

 if ((new_fd = accept(sock_fd, (struct sockaddr *)&client_sock, (socklen_t *)&sin_size)) == -1)
 {
 perror("accept");
 continue;
 }

 cli_addr = malloc(sizeof(struct sockaddr));

 printf("accept addr\r\n");

 if (cli_addr != NULL)
 {
 memcpy(cli_addr, &client_sock, sizeof(struct sockaddr));
 }

 //处理目标
 ssize_t ret;

 while (1)
 {
 if ((ret = recv(new_fd, recvbuf, sizeof(recvbuf), 0)) == -1)
 {
 printf("recv error \r\n");
 }
 printf("recv :%s\r\n", recvbuf);
 sleep(2);
 if ((ret = send(new_fd, buf, strlen(buf) + 1, 0)) == -1)
 {
 perror("send : ");
 }

 sleep(2);
 }

 close(new_fd);
 }
}

将Hi3861、Dayu200都连接到同一个wifi下，事先匹配好IP地址和端口：

连接后Hi3861只要接收到数据就会返回一段字符串，Hi3861接收到的数据可以使用串口查看：

​​想了解更多关于开源的内容，请访问：​​

​​51CTO 开源基础软件社区​​

​​https://ost.51cto.com​​