ESP32 AysncWebServer

Question

我在使用ESP32时遇到了AsyncWebServer的问题。访问代码的url是ip/inline?a=5数字a=5控制AsyncWebServer将向客户端发送多少字符。当我通过浏览器访问它时，如果字符数在1到500个范围内，它可以正常工作，浏览器通过在窗口中显示数据来工作。然而，当我到达600及以上时，董事会或重置或停止响应一段时间，浏览器窗口永远不会恢复。最初我认为这是内存的一个问题，因为字符串不能有2000+字符，所以它已经很低了。

有人能告诉我怎么解决吗？另外，我想显示一个非常长的HTML字符串给浏览器，可能有10K字符。我能做这个吗？多么?它与其他应用程序代码相结合。我抄袭并简化了它。编译器在收到实际应用程序后的消息显示，我仍然有很多可用的内存。

我的密码在这里

#include <WiFi.h>
#include <WiFiClient.h>
#include <WebServer.h>
#include <ESPmDNS.h>

const char* ssid = "****";
const char* password = "***";
;

WebServer server(80);

const int led = 13;

void handleRoot() {
  digitalWrite(led, 1);
  server.send(200, "text/plain", "hello from esp32!");
  digitalWrite(led, 0);
}

void handleNotFound() {
  digitalWrite(led, 1);
  String message = "File Not Found\n\n";
  message += "URI: ";
  message += server.uri();
  message += "\nMethod: ";
  message += (server.method() == HTTP_GET) ? "GET" : "POST";
  message += "\nArguments: ";
  message += server.args();
  message += "\n";
  for (uint8_t i = 0; i < server.args(); i++) {
    message += " " + server.argName(i) + ": " + server.arg(i) + "\n";
  }
  server.send(404, "text/plain", message);
  digitalWrite(led, 0);
}

void setup(void) {
  pinMode(led, OUTPUT);
  digitalWrite(led, 0);
  Serial.begin(115200);
  WiFi.mode(WIFI_STA);
  WiFi.begin(ssid, password);
  Serial.println("");

  // Wait for connection
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("");
  Serial.print("Connected to ");
  Serial.println(ssid);
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());

  if (MDNS.begin("esp32")) {
    Serial.println("MDNS responder started");
  }

  server.on("/", handleRoot);

  server.on("/inline", []() 
  {
        String content="\0";
        String random_data=F("<br />Apart from counting words and characters, our online editor can help you to improve 1234<br />");
        
    
      for (int i=1;i<=100*9;i++)
      {
        //serial.print(i); 
        content=content+i;
        content=content+random_data;
      }
      

    
    server.send(200, "text/html", content);
  });

  server.onNotFound(handleNotFound);

  server.begin();
  Serial.println("HTTP server started");
}

void loop(void) {
  server.handleClient();
  delay(2);//allow the cpu to switch to other tasks
}

Answer 1

代码的格式不正确。

首先是一个正确的模型，并给出了一个示例：

server.on("/inline", HTTP_GET, [](AsyncWebServerRequest *request) {
    // Check if we have a param.
    // If not, return with 500 internal error.
    if( !request->hasParam("a") ){
        request->send(500, "text/plain", "Please fill param!");
    }
    AsyncWebParameter* p = request->getParam("a");
    int charAmountRequested = p->value().toInt();

    // Create a char array with the requested size.
    char content[charAmountRequested];
    for (size_t i = 0; i < charAmountRequested; i++){
        content[i] = 'g';
    }
    request->send(200, "text/html", content);
});

如果您绝对想用字符串来完成它，下面是另一个示例：

server.on("/inline", HTTP_GET, [](AsyncWebServerRequest *request) {
    // Check if we have a param.
    // If not, return with 500 internal error.
    if( !request->hasParam("a") ){
        request->send(500, "text/plain", "Please fill param!");
    }
    String content;
    AsyncWebParameter* p = request->getParam("a");
    int charAmountRequested = p->value().toInt();
    for (size_t i = 0; i < charAmountRequested; i++){
        content += "g";
    }
    request->send(200, "text/html", content);
});

注:这些是未经测试的代码，但它应该给你一个想法。