Question

对预检请求的响应未通过访问控制检查：否请求中存在“ Access-Control-Allow-Origin”标头资源。因此，不允许原点“ http://192.168.100.2:8100” 访问。响应的HTTP状态代码为404。

尝试在物联网ESP8266 Web服务器中调用put / post请求时，我遇到了以上错误。

为了解决这个问题，我尝试添加以下代码。但没有任何效果。

server.on("/", HTTP_OPTIONS, []() {
    server.sendHeader("Access-Control-Allow-Origin", "*");
    server.sendHeader("Allow", "HEAD,GET,PUT,POST,DELETE,OPTIONS");
    server.sendHeader("Access-Control-Allow-Methods", "GET, HEAD, POST, PUT");
    server.sendHeader("Access-Control-Allow-Headers", "X-Requested-With, X-HTTP-Method-Override, Content-Type, Cache-Control, Accept");
});

server.on("/testPost", HTTP_POST, testCors);
server.on("/testPut", HTTP_PUT, testCors);

在函数内部

void testCors()
{
    Serial.print("HTTP Method: ");
    Serial.println(server.method());

    server.sendHeader("Access-Control-Allow-Origin", "*");
    server.sendHeader("Allow", "HEAD,GET,PUT,POST,DELETE,OPTIONS");
    server.sendHeader("Access-Control-Allow-Methods", "GET, HEAD, POST, PUT");
    server.sendHeader("Access-Control-Allow-Headers", "X-Requested-With, X-HTTP-Method-Override, Content-Type, Cache-Control, Accept");
    server.send(200, "text/plain", "");
}

谢谢

Answer 1

这是适用于我的通配符路径的解决方案

void config_rest_server_routing()
{
    server.on("/", HTTP_GET, []() {
        server.send(200, "text/html",
                    "Welcome to the ESP8266 REST Web Server");
    });
    server.on("/leds", HTTP_GET, get_leds);
    server.on("/leds", HTTP_POST, testCors);
    server.on("/leds", HTTP_PUT, testCors);

    server.onNotFound(handleNotFound);
}
void handleNotFound()
{
    if (server.method() == HTTP_OPTIONS)
    {
        server.sendHeader("Access-Control-Allow-Origin", "*");
        server.sendHeader("Access-Control-Max-Age", "10000");
        server.sendHeader("Access-Control-Allow-Methods", "PUT,POST,GET,OPTIONS");
        server.sendHeader("Access-Control-Allow-Headers", "*");
        server.send(204);
    }
    else
    {
        server.send(404, "text/plain", "");
    }
}

Answer 2

只需在每个响应之前添加以下行：

server.sendHeader("Access-Control-Allow-Origin", "*");

nodemcu esp8266中的CORS问题

2 个答案: