Question

我刚刚得到一个Arduino并开始学习C ++。我决定首先实施一个简单的汽车躲闪＆＃34;游戏，使用液晶显示屏和按钮出现在那些very old "9999 in 1" handhelds中。但是我在代码中遇到了一个非常奇怪的问题。

编译器认为我试图覆盖setUp和tearDown，但我无法看到这种情况发生在哪里。实际上没有比原始函数定义更多的实例，但是当我尝试编译时会发生这种情况（使用Stino作为Sublime Text，如果相关的话）：

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]

这是＆＃34;游戏＆＃34;源文件lcd.ino，其中没有游戏内容：

#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);
}

编辑： lcd.ino.cpp内容，由Arduino构建工具生成：

#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);
}

我在这里缺少什么？

Answer 1

答案可能有点晚，但是;

似乎Arduino IDE不喜欢在类定义中声明的成员函数。

要明确：

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

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

Answer 2

从MS C ++帮助：

必须定义基类中的虚函数，除非使用pure-specifier声明它们。

我认为基类中的null定义可能是问题所在。使基类声明为纯，并删除空定义，或提供诊断非空定义。

Answer 3

在我的特殊情况下，发生错误是因为我不小心多次声明了相同的函数。一旦我删除了额外的函数声明，问题就解决了。

＆＃34;错误：＆＃39; A＆＃39;不能超载＆＃34;，但代码中没有任何重载

3 个答案: