我是 javascript/typescript 开发人员,但对 Arduino/c++ 很陌生
我有一个类(见下面的 h 和 cpp)并且有这个编译器错误:
DotMatrix.cpp:13:1: error: redefinition of 'DotMatrix::DotMatrix(uint8_t, MD_MAX72XX::moduleType_t, uint8_t, uint8_t, uint8_t)'
DotMatrix::DotMatrix(uint8_t maxDevices, MD_MAX72XX::moduleType_t hardwareType, uint8_t clkPin, uint8_t dataPin, uint8_t csPin)
^
In file included from sketch/DotMatrix.cpp:5:0:
DotMatix.h:10:3: error: 'DotMatrix::DotMatrix(uint8_t, MD_MAX72XX::moduleType_t, uint8_t, uint8_t, uint8_t)' previously defined here
DotMatrix(uint8_t maxDevices, MD_MAX72XX::moduleType_t hardwareType, uint8_t clkPin, uint8_t dataPin, uint8_t csPin)
^
exit status 1
我不明白为什么...以下是文件:
DotMatix.h:
#ifndef DotMatrix_h
#define DotMatrix_h
#include <MD_MAX72xx.h>
#include <MD_Parola.h>
class DotMatrix
{
public:
DotMatrix(uint8_t maxDevices, MD_MAX72XX::moduleType_t hardwareType, uint8_t clkPin, uint8_t dataPin, uint8_t csPin)
: _parola(hardwareType, csPin, maxDevices)
{};
void setup();
private:
MD_Parola _parola;
};
#endif
DotMatix.cpp:#ifndef DotMatrix_cpp
#define DotMatrix_cpp
//#include <stdint.h>
#include "DotMatix.h"
#include "Arduino.h"
#include <MD_Parola.h> // Parola library to scroll and display text on the display (needs MD_MAX72xx library) https://github.com/MajicDesigns/MD_Parola
#include <MD_MAX72xx.h> // Library to control the Maxim MAX7219 chip on the dot matrix module https://github.com/MajicDesigns/MD_MAX72XX
const int FRAME_DELAY = 25;
DotMatrix::DotMatrix(uint8_t maxDevices, MD_MAX72XX::moduleType_t hardwareType, uint8_t clkPin, uint8_t dataPin, uint8_t csPin)
: _parola(hardwareType, csPin, maxDevices)
{
//MD_Parola(MD_MAX72XX::moduleType_t mod, uint8_t csPin, uint8_t numDevices = (uint8_t)'\001')
_parola = MD_Parola(hardwareType, csPin, maxDevices);
}
void DotMatrix::setup()
{
this->_parola.begin();
_parola.displayClear();
_parola.displaySuspend(false);
byte i = 3; //EEPROM.read(0);
_parola.setIntensity(i); // Values from 0 to 15
_parola.setTextEffect(PA_SCROLL_LEFT, PA_SCROLL_LEFT); //in and out effect
_parola.displayScroll("Hallokes ...", PA_LEFT, PA_SCROLL_LEFT, FRAME_DELAY);
}
#endif
作为引用,这是调用该类的 ino 文件的(片段):#include "DotMatix.h"
// Define the number of 8x8 dot matrix devices and the hardware SPI interface
#define MAX_DEVICES 4
#define HARDWARE_TYPE MD_MAX72XX::DR1CR0RR0_HW
#define CLK_PIN 14 //D5
#define DATA_PIN 13 //D7
#define CS_PIN 2 //D4
DotMatrix dotMatrix(MAX_DEVICES, HARDWARE_TYPE, CLK_PIN, DATA_PIN, CS_PIN);
void setup() {
dotMatrix.setup();
}
void loop() {
}
我正在使用带有 Arduino 扩展的 VS Code IDE。
最佳答案
void func(); // function declaration
void func() { blablabla; } // function definition.
您可能会看到定义和声明之间的简单区别。一个有{
,另一个没有。 (全局)函数只能在代码库中定义一次,而不是两次。否则你的编译器将不知道选择哪个函数——第一个?第二个?你做了:
// in DotMatix.h:
DotMatrix(blablaa)
{}; // yes this is definition
并且还做了:// in DotMatrix.cpp
DotMatrix::DotMatrix(ublabla, who cares)
{ // also definition
编译器看到同一函数的两个定义并退出并出现错误。包含保护通常用于防止包含相同的文件两次。您的多个定义在多个文件中。也不需要在源文件中包含保护 - 源文件不应该被包含,所以它们总是被处理一次。
关于c++ - 尽管使用了包含防护,但错误 : redefinition of class,,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/63325411/