ESP32-C3， esp-idf 4.3.5，连入指定无线网后做为tcp client循环向指定ip收发数据，要有重连机制，提供个例程，

以下是一个简单的 ESP32-C3 ESP-IDF 4.3.5 示例程序，它将作为 TCP 客户端连接到指定的 IP 地址，并循环收发数据。如果连接断开，它将尝试重新连接。

#include <stdio.h>
#include <string.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_wifi.h"
#include "esp_system.h"
#include "esp_event.h"
#include "esp_log.h"
#include "esp_netif.h"
#include "esp_tls.h"
#include "lwip/sockets.h"
#include "lwip/dns.h"
#include "lwip/netdb.h"

#define WIFI_SSID      "your_wifi_ssid"
#define WIFI_PASSWORD  "your_wifi_password"
#define HOST_IP_ADDR   "10.0.0.2"
#define HOST_PORT      1234

#define TAG "TCP_CLIENT"

static int s_retry_num = 0;

static void wifi_event_handler(void* arg, esp_event_base_t event_base,
                                int32_t event_id, void* event_data)
{
    switch (event_id) {
        case WIFI_EVENT_STA_START:
            esp_wifi_connect();
            break;
        case WIFI_EVENT_STA_DISCONNECTED:
            if (s_retry_num < 3) {
                esp_wifi_connect();
                s_retry_num++;
                ESP_LOGI(TAG, "retry to connect to the AP");
            }
            break;
        default:
            break;
    }
}

static void tcp_client_task(void* arg)
{
    char rx_buffer[128];
    char tx_buffer[128];
    int sock = -1;
    struct sockaddr_in server_addr;

    while (1) {
        // Wait for Wi-Fi connection
        xEventGroupWaitBits(wifi_event_group, WIFI_CONNECTED_BIT, false, true, portMAX_DELAY);

        // Create socket
        sock = socket(AF_INET, SOCK_STREAM, IPPROTO_IP);
        if (sock < 0) {
            ESP_LOGE(TAG, "Failed to create socket");
            break;
        }

        // Set server address
        memset(&server_addr, 0, sizeof(server_addr));
        server_addr.sin_family = AF_INET;
        server_addr.sin_addr.s_addr = inet_addr(HOST_IP_ADDR);
        server_addr.sin_port = htons(HOST_PORT);

        // Connect to server
        if (connect(sock, (struct sockaddr*)&server_addr, sizeof(server_addr)) != 0) {
            ESP_LOGE(TAG, "Failed to connect to server");
            close(sock);
            continue;
        }

        ESP_LOGI(TAG, "Connected to server");

        while (1) {
            // Receive data from server
            int rx_len = recv(sock, rx_buffer, sizeof(rx_buffer) - 1, 0);
            if (rx_len < 0) {
                ESP_LOGE(TAG, "Failed to receive data");
                break;
            } else if (rx_len == 0) {
                ESP_LOGI(TAG, "Server disconnected");
                break;
            }

            rx_buffer[rx_len] = '\0';
            ESP_LOGI(TAG, "Received: %s", rx_buffer);

            // Send data to server
            sprintf(tx_buffer, "Hello, server!");
            int tx_len = send(sock, tx_buffer, strlen(tx_buffer), 0);
            if (tx_len < 0) {
                ESP_LOGE(TAG, "Failed to send data");
                break;
            }
        }

        close(sock);
    }

    vTaskDelete(NULL);
}

void app_main(void)
{
    // Initialize Wi-Fi
    tcpip_adapter_init();
    wifi_event_group = xEventGroupCreate();
    esp_event_loop_create_default();
    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
    esp_wifi_init(&cfg);
    esp_wifi_set_mode(WIFI_MODE_STA);
    esp_wifi_set_config(ESP_IF_WIFI_STA, &wifi_config);
    esp_wifi_start();

    // Register Wi-Fi event handler
    esp_event_handler_instance_t instance_any_id;
    esp_event_handler_instance_t instance_got_ip;
    esp_event_handler_instance_register(WIFI_EVENT, ESP_EVENT_ANY_ID, &wifi_event_handler, NULL, &instance_any_id);
    esp_event_handler_instance_register(IP_EVENT, IP_EVENT_STA_GOT_IP, &wifi_event_handler, NULL, &instance_got_ip);

    // Wait for Wi-Fi connection
    xEventGroupWaitBits(wifi_event_group, WIFI_CONNECTED_BIT, false, true, portMAX_DELAY);

    // Start TCP client task
    xTaskCreate(tcp_client_task, "tcp_client_task", 4096, NULL, 5, NULL);
}

请注意，此示例程序假定您已经将 Wi-Fi 配置为连接到指定的 SSID，并已经设置了 Wi-Fi 密码。如果您还没有这样做，请将 `WIFI_SSID` 和 `WIFI_PASSWORD` 宏定义替换为您自己的 SSID 和密码。