PlatformIO 对已定义属性的未识别引用错误

Question

我正在使用 PlatformIO 和 Nodemcuv2 微控制器创建一个项目。

我写了一个class用于串口通信SerialCommunicationHandler。这个 class ICommunicationHandler 实现了一个接口。请参阅下面的代码。

ICommunicationHandler.h

class ICommunicationHandler {
public:
    virtual void sendTemperature(float temp) = 0;
    virtual void receiveData() = 0;
    virtual void update() = 0;

protected:
    virtual void parseData() = 0;
    virtual void showParsedData() = 0;
};

SerialCommunicationHandler

头文件

#include "ICommunicationHandler.h"
class SerialCommunicationHandler : public ICommunicationHandler {
private:
//atributes needed for storing and modifying incoming data.

    static char incomingData[6]; //char array to temporarily store incoming data.
    static char receivedData[6]; //char array to copy incoming data to.
    static unsigned int messagePosition; //index of the incomingData array.

    bool receiving;
    bool newData;
    void parseData() override;
    void receiveData() override;
    void showParsedData() override;

public:
    explicit SerialCommunicationHandler();
    void sendTemperature(float temp) override;
    void update() override;
};

.cpp

#include <Arduino.h>
#include "SerialCommunicationHandler.h"

SerialCommunicationHandler::SerialCommunicationHandler() {
    messagePosition = 0;
    receiving = false;
    newData = false;
}

void SerialCommunicationHandler::receiveData() {
    //check if there are bytes in the serial buffer.
    while (Serial.available() > 0){
        char inByte = Serial.read();
        //check if the byte is a starting or ending character;
        switch (inByte) {
            case '<':
                //start receiving characters
                receiving = true;
                break;
            case '>':
                //stop receiving and parse the incoming data.
                receiving = false;
                newData = true;
                strcpy(receivedData, incomingData); //copy incoming data into receivedData for further parsing.
                memset(incomingData, 0, sizeof(incomingData)); //resetting incomingData.
                messagePosition = 0;
                break;
            default:
                if (receiving) {
                    incomingData[messagePosition] = inByte; //add incoming byte to array.
                    messagePosition++;
                }
                break;
        }
    }
}

void SerialCommunicationHandler::parseData() {
    if (newData) {
        showParsedData();
    }
    newData = false;
}

void SerialCommunicationHandler::showParsedData() {
    Serial.println(receivedData);
}

void SerialCommunicationHandler::sendTemperature(float temp) {
    Serial.println(temp);
}

void SerialCommunicationHandler::update() {
    receiveData();
    parseData();
}

构建时出现多个未定义的引用错误：

*/ld.exe: .pio\build\nodemcuv2\src\SerialCommunicationHandler.cpp.o:(.text._ZN26SerialCommunicationHandler14s
howParsedDataEv+0x0): undefined reference to `_ZN26SerialCommunicationHandler12receivedDataE`
*/ld.exe: .pio\build\nodemcuv2\src\SerialCommunicationHandler.cpp.o:(.text._ZN26SerialCommunicationHandlerC2E
v+0x4): undefined reference to `_ZN26SerialCommunicationHandler15messagePositionE'
*/ld.exe: .pio\build\nodemcuv2\src\SerialCommunicationHandler.cpp.o:(.text._ZN26SerialCommunicationHandler11r
eceiveDataEv+0x0): undefined reference to `_ZN26SerialCommunicationHandler12incomingDataE'

collect2.exe: error: ld returned 1 exit status
*** [.pio\build\nodemcuv2\firmware.elf] Error 1

我已多次检查我的代码是否存在语法错误或拼写错误，但一无所获。我的 IDE 也没有出现任何错误。欢迎提供有关可能导致未定义引用错误的任何信息。

Answer 1

头文件

#include "ICommunicationHandler.h"

class SerialCommunicationHandler : public ICommunicationHandler {
private:
//atributes needed for storing and modifying incoming data.
static char incomingData[6]; //char array to temporarily store incoming data.
static char receivedData[6]; //char array to copy incoming data to.
static unsigned int messagePosition; //index of the incomingData array.
   // ... etc

这些只是静态成员变量的声明。您还必须在 cpp 文件中定义它们，就像您对成员函数所做的那样：

.cpp 文件：

void SerialCommunicationHandler::showParsedData() {
    Serial.println(receivedData);
}

// static data members
char SerialCommunicationHandler::incomingData[6] = {};
char SerialCommunicationHandler::receivedData[6] = {};
unsigned int SerialCommunicationHandler::messagePosition = 0;

PlatformIO 对已定义属性的未识别引用错误

PlatformIO Unidentified reference error to defined attributes

c++

platformio

ICommunicationHandler.h

SerialCommunicationHandler