c++ - 无效的构造函数 token C++ Arduino

Question

我遇到了错误

C:\Users\Jake\Documents\Arduino\libraries\Sonar\Sonar.cpp:3:13: error: expected >constructor, destructor, or type conversion before '(' token Sonar::Sonar(trigLeft,echoLeft,trigRight, echoRight) Error compiling.

我不知道是什么原因造成的，有一次缺少花括号，但我重新添加了它。代码如下

声纳.cpp:

#include "Sonar.h"

Sonar::Sonar(trigLeft,echoLeft,trigRight, echoRight) {
    pinMode(triggerPinLeft,OUTPUT);
    pinMode(triggerPinRight,OUTPUT);
    pinMode(echoPinLeft,INPUT);
    pinMode(echoPinRight,INPUT);

    triggerPinLeft = trigLeft;
    echoPinLeft = echoRight;
    triggerPinRight = trigRight;
    echoPinRight = echoRight;

}



void Sonar::Ping() {

  digitalWrite(triggerPinLeft, LOW);
  digitalWrite(triggerPinRight, LOW);
  delayMicroseconds(2);
  digitalWrite(triggerPinLeft, HIGH);
  digitalWrite(triggerPinRight, HIGH);;
  delayMicroseconds(5);
  digitalWrite(triggerPinLeft, LOW);
  digitalWrite(triggerPinRight, LOW);

  // Read EchoPins

  long durationLeft = pulseIn(echoPinLeft, HIGH);
  long durationRight = pulseIn(echoPinRight, HIGH);

  // convert the time into a distance

  cmLeft = microsecondsToCentimeters(durationLeft);
  cmRight - microsecondsToCentimeters(durationRight);

  delay(100);
}

long Sonar::microsecondsToCentimeters(long microseconds) {
    // The speed of sound is 340 m/s or 29 microseconds per centimeter.

    return microseconds / 58;
}

声纳.h:

#ifndef Sonar_h
#define Sonar_h

#include "Arduino.h"

class Sonar {
  public:
    Sonar(int,int,int,int);
    long cmLeft,cmRight;
    void Ping();
  private:
    const int triggerPinLeft,echoPinLeft,triggerPinRight,echoPinRight;
    long microsecondsToInches(long microseconds);
    long microsecondsToCentimeters(long microseconds);
};

#endif

最后是 Sonar.ino(这是给 Arduino 的，我相信它工作正常)

#include <Sonar.h>

Sonar sonar(20,21,22,23);
void setup() {
// put your setup code here, to run once:
}

void loop() {
  // put your main code here, to run repeatedly:
  sonar.Ping();
  long sonarLeftDistance = sonar.cmLeft;
  long sonarRightDistance = sonar.cmRight;

}

这就是全部代码。 Arduino 位在很大程度上是无关紧要的。

Answer 1

您没有根据构造函数声明在函数定义中指定参数类型:

Sonar(int,int,int,int); // Declaration

---

Sonar::Sonar(int trigLeft, int echoLeft, int trigRight, int echoRight) {
          // ^^^           ^^^           ^^^            ^^^
    // ...
}

由于对应的类成员变量声明为const

    const int triggerPinLeft,echoPinLeft,triggerPinRight,echoPinRight;
 // ^^^^^  

它们需要使用构造函数成员初始化列表进行初始化:

Sonar::Sonar(int trigLeft, int echoLeft, int trigRight, int echoRight) 
: triggerPinLeft(trigLeft)
, echoPinLeft(echoLeft)
, triggerPinRight(trigRight)
, echoPinRight(echoRight) {
}

这是唯一的方法。