c++ - 实现 TimeLib.h 的 Arduino 类

Question

我正在为使用 TimeLib.h 库的 ESP8266-Arduino 创建这个库。

在我的标题中我有:

WiFiUDP *_UdpNTP = NULL;
void    setupTime();
time_t  getNtpTime();
void    sendNTPpacket(WiFiUDP *u);

这些是我的功能:

void Konnec::setupTime() {
    setSyncProvider(getNtpTime);
    setSyncInterval(NTP_POL_TIME);
}


time_t Konnec::getNtpTime() {
//WiFiUDP udp;
//udp.begin(localPort);

_UdpNTP = new WiFiUDP();
_UdpNTP->begin(localPort);

while (_UdpNTP->parsePacket() > 0); // discard any previously received packets
for (int i = 0; i < 5; i++) { // 5 retries.
    sendNTPpacket(_UdpNTP);
    uint32_t beginWait = millis();
    while (millis() - beginWait < 1000) {
        if (_UdpNTP->parsePacket()) {
            Serial.println("");
            Serial.println("Receive NTP Response");
            _UdpNTP->read(packetBuffer, NTP_PACKET_SIZE);
            // Extract seconds portion.
            unsigned long highWord = word(packetBuffer[40], packetBuffer[41]);
            unsigned long lowWord = word(packetBuffer[42], packetBuffer[43]);
            unsigned long secSince1900 = highWord << 16 | lowWord;
            _UdpNTP->flush();
            return secSince1900 - 2208988800UL + TIMEZONE * SECS_PER_HOUR;
        }
        delay(10);
    }
}
Serial.println("");
Serial.println("No NTP Response :-(");
return 0; // return 0 if unable to get the time
}

void Konnec::sendNTPpacket(WiFiUDP *u) {
// Zeroise the buffer.
memset(packetBuffer, 0, NTP_PACKET_SIZE);
memcpy(packetBuffer, sendBuffer, 16);

if (u->beginPacket(timeServer, 123)) {
    u->write(packetBuffer, NTP_PACKET_SIZE);
    u->endPacket();
}
}

这是我得到的错误:

konnec.cpp: 991:28: error: cannot convert 'Konnec::getNtpTime' from type 'time_t (Konnec::)() {aka long int (Konnec::)()}' to type 'getExternalTime {aka long int (*)()}
   setSyncProvider(getNtpTime)
Error compiling libraries

有人知道解决方案是什么吗？

Answer 1

问题似乎是 Konnec::getNtpTime 是一个类方法，而 setSyncProvider 需要一个函数。请记住，函数和方法是不同的东西，因为方法还需要知道它正在操作的特定类实例。

虽然查看您的代码，但看起来 getNtpTime 不依赖于您的类的任何特定内容，因此您可以将其声明为:

static time_t Konnec::getNtpTime();

这将使它被用作一个函数，因为它在那个时候是有效的。