在我的Arduino库中使用外部库(Use external library in my Arduino library)

编程入门行业动态更新时间:2024-10-11 17:25:50

我想创建一个个人库，在那里我使用另一个。在我的代码中，我在私有部分声明并初始化了库。

但我有错误'((LCD*)this)->LCD::lcd' does not have class type 。

我写了几个版本，但没有任何改变。我最多可以显示print Test01和test02 。

。H

#ifndef LCD_h
#define LCD_h

#include <LiquidCrystal_I2C.h>

class LCD{
  public:
    LCD();
    void firstLine();
    void secondLine(float tempInCelsius);

  private:
    LiquidCrystal_I2C lcd(0x27, 16, 2);
};

#endif
 
 的.cpp  
#include "LCD.h"
#include <LiquidCrystal_I2C.h>

LCD::LCD(){
    Serial.begin(9600);
    Serial.println("Test 01");
    lcd.init();
    lcd.backlight();
    lcd.setCursor(0, 0);
}

void LCD::secondLine(float tempInCelsius){
    Serial.println("Test 03");
    lcd.clear();
    lcd.setCursor(0, 1);
    lcd.print("T = ");
    lcd.print(tempInCelsius);
}
 
 .ino  
#include "LCD.h"


LCD CrystalLCD();

void setup(void)
{
    Serial.begin(9600);
    Serial.println("Test 02");
}

void loop(void)
{
    CrystalLCD.secondLine(1.40);
}
 
 我也会给你整个错误信息。  
[Starting] Verify sketch - arduino.ino
Loading configuration...
Initializing packages...
Preparing boards...
Verifying...
In file included from /Users/WorkSpace/Make/RucheChaufante/ino/LCD.cpp:1:0:
LCD.h:13: error: expected identifier before numeric constant
     LiquidCrystal_I2C lcd(0x27, 16, 2);
                           ^
LCD.h:13: error: expected ',' or '...' before numeric constant
/Users/WorkSpace/Make/RucheChaufante/ino/arduino.ino: In constructor 'LCD::LCD()':
arduino:9: error: '((LCD*)this)->LCD::lcd' does not have class type
     Serial.println("Test 02");
     ^
arduino:10: error: '((LCD*)this)->LCD::lcd' does not have class type
 }
     ^
arduino:11: error: '((LCD*)this)->LCD::lcd' does not have class type

     ^
/Users/WorkSpace/Make/RucheChaufante/ino/arduino.ino: In member function 'void LCD::secondLine(float)':
arduino:16: error: '((LCD*)this)->LCD::lcd' does not have class type
arduino:17: error: '((LCD*)this)->LCD::lcd' does not have class type
arduino:18: error: '((LCD*)this)->LCD::lcd' does not have class type
arduino:19: error: '((LCD*)this)->LCD::lcd' does not have class type
/Users/WorkSpace/Make/RucheChaufante/ino/arduino.ino: In function 'void loop()':
arduino:14: error: request for member 'secondLine' in 'CrystalLCD', which is of non-class type 'LCD()'
     CrystalLCD.secondLine(1.40);
                ^
exit status 1
[Error] Exit with code=1
I would like to create a personal library where I use another one. In my code I declared and initialized the library in the private part. 
But I have the error '((LCD*)this)->LCD::lcd' does not have class type. 
I've written several versions, but nothing changes. At best I can display the print Test01 and test02. 
.h 
#ifndef LCD_h
#define LCD_h

#include <LiquidCrystal_I2C.h>

class LCD{
  public:
    LCD();
    void firstLine();
    void secondLine(float tempInCelsius);

  private:
    LiquidCrystal_I2C lcd(0x27, 16, 2);
};

#endif
 
.cpp 
#include "LCD.h"
#include <LiquidCrystal_I2C.h>

LCD::LCD(){
    Serial.begin(9600);
    Serial.println("Test 01");
    lcd.init();
    lcd.backlight();
    lcd.setCursor(0, 0);
}

void LCD::secondLine(float tempInCelsius){
    Serial.println("Test 03");
    lcd.clear();
    lcd.setCursor(0, 1);
    lcd.print("T = ");
    lcd.print(tempInCelsius);
}
 
.ino 
#include "LCD.h"


LCD CrystalLCD();

void setup(void)
{
    Serial.begin(9600);
    Serial.println("Test 02");
}

void loop(void)
{
    CrystalLCD.secondLine(1.40);
}
 
I'll give you the entire error message, too. 
[Starting] Verify sketch - arduino.ino
Loading configuration...
Initializing packages...
Preparing boards...
Verifying...
In file included from /Users/WorkSpace/Make/RucheChaufante/ino/LCD.cpp:1:0:
LCD.h:13: error: expected identifier before numeric constant
     LiquidCrystal_I2C lcd(0x27, 16, 2);
                           ^
LCD.h:13: error: expected ',' or '...' before numeric constant
/Users/WorkSpace/Make/RucheChaufante/ino/arduino.ino: In constructor 'LCD::LCD()':
arduino:9: error: '((LCD*)this)->LCD::lcd' does not have class type
     Serial.println("Test 02");
     ^
arduino:10: error: '((LCD*)this)->LCD::lcd' does not have class type
 }
     ^
arduino:11: error: '((LCD*)this)->LCD::lcd' does not have class type

     ^
/Users/WorkSpace/Make/RucheChaufante/ino/arduino.ino: In member function 'void LCD::secondLine(float)':
arduino:16: error: '((LCD*)this)->LCD::lcd' does not have class type
arduino:17: error: '((LCD*)this)->LCD::lcd' does not have class type
arduino:18: error: '((LCD*)this)->LCD::lcd' does not have class type
arduino:19: error: '((LCD*)this)->LCD::lcd' does not have class type
/Users/WorkSpace/Make/RucheChaufante/ino/arduino.ino: In function 'void loop()':
arduino:14: error: request for member 'secondLine' in 'CrystalLCD', which is of non-class type 'LCD()'
     CrystalLCD.secondLine(1.40);
                ^
exit status 1
[Error] Exit with code=1

                最满意答案
                
                    
                         您无法在类声明中初始化成员。 试试：  
class LCD
{   
  public:
    LCD();
    void firstLine();
    void secondLine(float tempInCelsius);

  private:
    LiquidCrystal_I2C lcd; 
};
 
 但是您可以在构造函数中初始化这些成员（ 必须 ，如果它们不提供默认构造函数）。 试试：  
LCD::LCD() : lcd(0x27, 16, 2) {
    Serial.begin(9600);
    Serial.println("Test 01");
    lcd.init();
    lcd.backlight();
    lcd.setCursor(0, 0);
}
You cannot initialize members in the class declaration. Try with: 
class LCD
{   
  public:
    LCD();
    void firstLine();
    void secondLine(float tempInCelsius);

  private:
    LiquidCrystal_I2C lcd; 
};
 
But you can initialize such members (must, if they do not provide a default constructor) in the constructor(s). Try with: 
LCD::LCD() : lcd(0x27, 16, 2) {
    Serial.begin(9600);
    Serial.println("Test 01");
    lcd.init();
    lcd.backlight();
    lcd.setCursor(0, 0);
}