「錯誤：'A'不能超載」，但代碼中沒有任何超載

Question

我剛剛得到了一個Arduino並開始學習C++。我決定開始實施一個簡單的「汽車閃避」遊戲，使用LCD和按鈕在very old "9999 in 1" handhelds中出現。不過，我遇到了一個代碼非常奇怪的問題。

編譯器認爲我試圖覆蓋setUp和tearDown，但我無法看到發生了什麼。從字面上有比原來的函數定義沒有進一步的情況，然而，這是當我嘗試編譯發生了什麼（使用Stino爲崇高的文本，如果這是相關的）：

Compiling lcd... 
Creating C:\Users\Leonardo\Documents\Arduino_Build\lcd\lcd.ino.cpp.o... 
C:\Users\Leonardo\Documents\Arduino_Build\lcd\lcd.ino.cpp:31: error: 'virtual void Scene::setUp(LiquidCrystal)' cannot be overloaded 
C:\Users\Leonardo\Documents\Arduino_Build\lcd\lcd.ino.cpp:25: error: with 'virtual void Scene::setUp(LiquidCrystal)' 
C:\Users\Leonardo\Documents\Arduino_Build\lcd\lcd.ino.cpp:32: error: 'virtual void Scene::tearDown(LiquidCrystal)' cannot be overloaded 
C:\Users\Leonardo\Documents\Arduino_Build\lcd\lcd.ino.cpp:26: error: with 'virtual void Scene::tearDown(LiquidCrystal)' 
[Stino - Error 1] 

這是「遊戲」的源文件， lcd.ino，其中有沒有什麼遊戲尚未：

#include "LiquidCrystal.h" 

#define LEFT_BUTTON_PIN 8 
#define RIGHT_BUTTON_PIN 7 

#define LEFT_PRESSED B10 
#define RIGHT_PRESSED B01 

#define STATE_SPLASH 0 
#define STATE_PLAY 1 
#define STATE_SCORE 2 

// LiquidCrystal display with: 
// rs on pin 12 
// rw on pin 11 
// enable on pin 10 
// d4, d5, d6, d7 on pins 5, 4, 3, 2 
LiquidCrystal lcd(12, 11, 10, 5, 4, 3, 2); 


class Scene { 
    public: 
    virtual void loop(byte input, LiquidCrystal lcd) {} 
    virtual void setUp(LiquidCrystal lcd) {} 
    virtual void tearDown(LiquidCrystal lcd) {} 
}; 

class Splash : public Scene { 
    public: void loop(byte input, LiquidCrystal lcd) { 
     lcd.print("Welcome to CAR DODGE"); 
     lcd.print("Press LEFT to start!"); 
    } 
}; 

class Game : public Scene { 
    public: void loop(byte input, LiquidCrystal lcd) { 
     lcd.print("HI"); 
    } 
}; 

class Score : public Scene { 
    public: void loop(byte input, LiquidCrystal lcd) { 
     lcd.print("HI"); 
    } 
}; 


byte currentMode = STATE_SPLASH; 
Scene *gameModes[] = {new Splash(), new Game(), new Score()}; 

byte getInput() { 
    bool leftSample1 = digitalRead(LEFT_BUTTON_PIN); 
    bool rightSample1 = digitalRead(RIGHT_BUTTON_PIN); 
    Serial.print(leftSample1); 
    Serial.print(" "); 
    Serial.println(rightSample1); 
} 

void changeGameMode(byte next) { 
    gameModes[currentMode]->tearDown(lcd); 
    gameModes[next]->setUp(lcd); 
    currentMode = next; 
} 

void setup() { 
    Serial.begin(9600); 

    pinMode(LEFT_BUTTON_PIN, INPUT); 
    pinMode(RIGHT_BUTTON_PIN, INPUT); 
    lcd.begin(20, 4); 

    changeGameMode(STATE_SPLASH); 
} 

void loop() { 
    byte input = getInput(); 
    gameModes[currentMode]->loop(input, lcd); 
    delay(150); 
} 

編輯： lcd.ino.cpp內容，這是由Arduino的產生構建工具：

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

#define LEFT_BUTTON_PIN 8 
#define RIGHT_BUTTON_PIN 7 

#define LEFT_PRESSED B10 
#define RIGHT_PRESSED B01 

#define STATE_SPLASH 0 
#define STATE_PLAY 1 
#define STATE_SCORE 2 

// LiquidCrystal display with: 
// rs on pin 12 
// rw on pin 11 
// enable on pin 10 
// d4, d5, d6, d7 on pins 5, 4, 3, 2 
LiquidCrystal lcd(12, 11, 10, 5, 4, 3, 2); 


class Scene { 
    public: 

virtual void setUp(LiquidCrystal lcd); 
virtual void tearDown(LiquidCrystal lcd); 
byte getInput(); 
void changeGameMode(byte next); 

virtual void loop(byte input, LiquidCrystal lcd) {} 
    virtual void setUp(LiquidCrystal lcd) {} 
    virtual void tearDown(LiquidCrystal lcd) {} 
}; 

class Splash : public Scene { 
    public: void loop(byte input, LiquidCrystal lcd) { 
     lcd.print("Welcome to CAR DODGE"); 
     lcd.print("Press LEFT to start!"); 
    } 
}; 

class Game : public Scene { 
    public: void loop(byte input, LiquidCrystal lcd) { 
     lcd.print("HI"); 
    } 
}; 

class Score : public Scene { 
    public: void loop(byte input, LiquidCrystal lcd) { 
     lcd.print("HI"); 
    } 
}; 


byte currentMode = STATE_SPLASH; 
Scene *gameModes[] = {new Splash(), new Game(), new Score()}; 

byte getInput() { 
    bool leftSample1 = digitalRead(LEFT_BUTTON_PIN); 
    bool rightSample1 = digitalRead(RIGHT_BUTTON_PIN); 
    Serial.print(leftSample1); 
    Serial.print(" "); 
    Serial.println(rightSample1); 
} 

void changeGameMode(byte next) { 
    gameModes[currentMode]->tearDown(lcd); 
    gameModes[next]->setUp(lcd); 
    currentMode = next; 
} 

void setup() { 
    Serial.begin(9600); 

    pinMode(LEFT_BUTTON_PIN, INPUT); 
    pinMode(RIGHT_BUTTON_PIN, INPUT); 
    lcd.begin(20, 4); 

    changeGameMode(STATE_SPLASH); 
} 

void loop() { 
    byte input = getInput(); 
    gameModes[currentMode]->loop(input, lcd); 
    delay(150); 
} 

我在這裏錯過了什麼？

Answer 1

答案可能有點遲，但;

看來Arduino IDE不喜歡在類定義中聲明的成員函數。

只是要清楚：

class example { 
    public: 
      void function(){ /*code not here*/ }; 
    private: 
      int variable; 
}; 

void example::function(){ 
    //code here 
} 

Answer 2

從MS C++幫助：

Virtual functions in a base class must be defined unless they are declared using the pure-specifier.

我想在基類中的定義無效可能是問題。可以使基類聲明爲純粹的，並刪除空定義，或提供診斷非空定義。