ESP32异步网络请求

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ESP32发起异步网络请求

序

之前做的GMartix在请求粉丝数量的时候，采用的是同步请求方式，同步请求会导致请求的时候产生阻塞。
很不够优雅，显得会卡住。所以这次做新作品，一定要试试异步请求，避免这种尴尬的阻塞！

异步请求库AsyncTCP-esphome

异步请求的操作由AsyncTCP-esphome提供。

示例代码

main.cpp
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#include <Arduino.h>
#include <AsyncTCP.h>
#include <WiFi.h>
#include <Wire.h>

#define ssid "XXXXXX"
#define password "XXXXXX"

WiFiClient client;

String response;

void asyncReqeust() {
  static AsyncClient *aClient;
  if (aClient) {
    // aClient already exists
    // aClient 繁忙
    return;
  }
  aClient = new AsyncClient();
  if (!aClient) {
    // could not allocate aClient
    // aClient 无法创建
    return;
  }
  aClient->onError(
      [&](void *arg, AsyncClient *client, int error) {
        Serial.println("getFollowersAsync:Connect Error");
        aClient = NULL;
        delete client;
      },
      NULL);

  aClient->onConnect(
      [&](void *arg, AsyncClient *client) {
        Serial.println("getFollowersAsync:Connected");
        aClient->onError(NULL, NULL);

        // 连接断开的动作
        client->onDisconnect(
            [&](void *arg, AsyncClient *c) {
              // finish = true;
              aClient = NULL;
              delete c;
              Serial.println("getFollowersAsync:Disconnected");
            },
            NULL);

        // 接收到服务器数据时候的动作
        client->onData(
            [&](void *arg, AsyncClient *c, void *data, size_t len) {
              uint8_t *d = (uint8_t *)data;
              for (size_t i = 0; i < len; i++) {
                Serial.write(d[i]);
              }
            },
            NULL);

        // send the request
        // 发送请求
        client->write(
            "GET /x/relation/stat?vmid=14374079 HTTP/1.1\r\nHost: "
            "api.bilibili.com\r\nContent-Type: application/json; "
            "charset=utf-8\r\n\r\n");
      },
      NULL);
  if (!aClient->connect("api.bilibili.com", 80)) {
    Serial.println("Connect Fail");
    AsyncClient *client = aClient;
    aClient = NULL;
    delete client;
  }
}

void setup() {
  Serial.begin(115200);
  client.setTimeout(1);
  WiFi.begin(ssid, password);
  WiFi.setAutoReconnect(true);
  delay(3000);
  asyncReqeust();
}

void loop() {}

正确连接WiFi后，打开串口就可以看到输出了