构造函数类需要参数但想将其用作属性 [英] Constructor class requires parameters but want to use it as a property

问题描述

所以我有一堂课

#include <SPI.h>
#include <Keypad.h>
#include "Debug.h"

class Keyblock {  
  private:
    Debug debug;
    Keypad keypad;
    
  public:
    void init(byte * keypadRowPins, byte * keypadColPins, Debug &debug);
    void read();
};


void Keyblock::init(byte * keypadRowPins, byte * keypadColPins, Debug &debug) {
  this->debug = debug;
  char keys[4][3] = {
    {'1','2','3'},
    {'4','5','6'},
    {'7','8','9'},
    {'*','0','#'}
  };
  keypad = Keypad(makeKeymap(keys), keypadRowPins, keypadColPins, 4, 3);
}

void Keyblock::read() {
  char key = keypad.getKey();
  debug.message(key);
}

使用 arduino 键盘库@https://playground.arduino.cc/Code/Keypad/

that uses the arduino keypad library @ https://playground.arduino.cc/Code/Keypad/

但是它发布错误(在帖子底部)因为(我相信)键盘构造函数需要参数.有什么技巧可以使我的班级工作或其他模式可以防止出现此问题?

However it is posting errors (at bottom of post) because (I believe) the Keypad constructor requires parameters. Is there a trick to making this work or another pattern for my class that will prevent this issue?

感谢您提供的任何帮助.我对这一切都很陌生.

Thanks for any help you can provide. I am very new at all of this.

In file included from sketch\Box.h:7:0,
                 from D:\source\Main\Main.ino:2:
sketch\Keyblock.h:8:7: note: 'Keyblock::Keyblock()' is implicitly deleted because the default definition would be ill-formed:
 class Keyblock {
       ^~~~~~~~
Keyblock.h:8:7: error: no matching function for call to 'Keypad::Keypad()'
In file included from sketch\Keyblock.h:5:0,
                 from sketch\Box.h:7,
                 from D:\source\Main\Main.ino:2:
C:\Users\campo\Documents\Arduino\libraries\Keypad\src/Keypad.h:78:2: note: candidate: Keypad::Keypad(char*, byte*, byte*, byte, byte)
  Keypad(char *userKeymap, byte *row, byte *col, byte numRows, byte numCols);
  ^~~~~~
C:\Users\----\Documents\Arduino\libraries\Keypad\src/Keypad.h:78:2: note:   candidate expects 5 arguments, 0 provided

推荐答案

有什么技巧可以使这项工作成功

Is there a trick to making this work

不是技巧，但由于 Keypad 没有默认构造函数，您需要在 您的Keyblock 构造函数的成员初始值设定项列表.

Not a trick, but since Keypad doesn't have a default constructor, you need to initialize it in the member initializer list of your Keyblock constructor(s).

示例:

class Keyblock {  
private:
    static constexpr byte ROWS = 4;
    static constexpr byte COLS = 3;

    char keys[ROWS][COLS] = {
      {'1','2','3'},
      {'4','5','6'},
      {'7','8','9'},
      {'*','0','#'}
    };

    // put your pins in these arrays:
    byte keypadRowPins[ROWS] = { 9, 8, 7, 6 };
    byte keypadColPins[COLS] = { 12, 11, 10 };

    Keypad keypad;

public:
    Keyblock(); // add a user-defined default constructor
};

Keyblock::Keyblock() : // member init-list between `:` and the body of the constructor
    keypad(makeKeymap(keys), keypadRowPins, keypadColPins, ROWS, COLS)
{}

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