ESP8266 SDK开发: 综合篇-8266TCP服务器与C#TCP客户端实现无线网络通信控制

    /*设置GPIO5为普通引脚*/
    PIN_FUNC_SELECT(PERIPHS_IO_MUX_GPIO5_U , FUNC_GPIO5);

/*用于返回继电器的状态*/
u8 RelayOn[4]={0x55,0xaa,0x01,0x01};//继电器吸合
u8 RelayOff[4]={0x55,0xaa,0x01,0x00};//继电器断开

/**
* @brief   TCP接收数据
* @param   arg:tcp_arg函数传入的参数
* * @param   p:接收的数据缓存
* @param   err:错误信息
* @param   None
* @retval  None
* @warning None
* @example
**/
static err_t net_tcp_recv_cb(void *arg, struct tcp_pcb *tpcb, struct pbuf *p, err_t err) {
    struct pbuf *q;
    u32 length = 0,i=0;
    tcp_pcb_server = tpcb;
    tcp_pcb_server_state = 1;
    if (!p || err!=ERR_OK) {
        if(p){
            pbuf_free(p);
        }
        tcp_pcb_server_state = 0;
        tcp_close(tcp_pcb_server);//关闭连接
        return ERR_CLSD;
    }
    //接收TCP数据(固定)
    for(q=p;q!=NULL;q=q->next){
        if(q->len > (TcpServerBuffLen-length))//接收的数据个数大于了数组可以接收的数据个数
            memcpy(TcpServerBuff+length,q->payload,(TcpServerBuffLen-length));//只接收数组可以接收的数据个数
        else
            memcpy(TcpServerBuff+length,q->payload,q->len);//接收TCP所有数据
        length += q->len;
        if(length > TcpServerBuffLen) break;
    }

    if(TcpServerBuff[0] == 0xaa && TcpServerBuff[1] == 0x55){
        if(TcpServerBuff[2] == 0x01){
            if(TcpServerBuff[3] == 0x01){
                GPIO_OUTPUT_SET(5, 1);//设置GPIO5输出高电平
                tcp_write(tcp_pcb_server, RelayOn, 4, TCP_WRITE_FLAG_COPY);//TCP_WRITE_FLAG_COPY:拷贝到发送缓存
                tcp_output(tcp_pcb_server);//立即发送
            }
            else if(TcpServerBuff[3] == 0x00){
                GPIO_OUTPUT_SET(5, 0);//设置GPIO5输出低电平
                tcp_write(tcp_pcb_server, RelayOff, 4, TCP_WRITE_FLAG_COPY);//TCP_WRITE_FLAG_COPY:拷贝到发送缓存
                tcp_output(tcp_pcb_server);//立即发送
            }
        }
    }

    //固定处理
    tcp_recved(tcp_pcb_server, p->tot_len);/*更新接收,告诉底层可以接着缓存数据了*/
    pbuf_free(p);//释放链表
    return ERR_OK;
}

            byte[] SendData = new byte[4];
            SendData[0] = 0xaa;
            SendData[1] = 0x55;
            SendData[2] = 0x01;
            SendData[3] = 0x01;
            if (button2.Text == "吸合")
            {
                SendData[3] = 0x01;
            }
            else if (button2.Text == "断开")
            {
                SendData[3] = 0x00;
            }
            try
            {
                MySocket.BeginSend(SendData, 0, SendData.Length, 0, null, null); //发送数据
            }
            catch (Exception) { }

                if (TCPBuffer[0] == 0x55 && TCPBuffer[1] == 0xaa)
                {
                    if (TCPBuffer[2] == 0x01)
                    {
                        if (TCPBuffer[3] == 0x01)//继电器吸合
                        {
                            Invoke((new Action(() => {//C# 3.0以后代替委托的新方法
                                label3.Text = "吸合";
                                button2.Text = "断开";
                            })));
                        }
                        else if (TCPBuffer[3] == 0x00)//继电器断开
                        {
                            Invoke((new Action(() => {//C# 3.0以后代替委托的新方法
                                label3.Text = "断开";
                                button2.Text = "吸合";
                            })));
                        }
                    }
                }