You can do it portably using SDL (the Simple DirectMedia Library), though I suspect you may not like its behavior. When I tried it, I had to have SDL create a new video window (even though I didn't need it for my program) and have this window "grab" almost all keyboard and mouse input (which was okay for my usage but could be annoying or unworkable in other situations). I suspect it's overkill and not worth it unless complete portability is a must--otherwise try one of the other suggested solutions.

顺便说一下，这将分别提供按键和释放事件，如果你喜欢的话。

适用于我的windows:

#include <conio.h>
char c = _getch();

下面是一个不向系统提供外壳的版本(在macOS 10.14上编写和测试)

#include <unistd.h>
#include <termios.h>
#include <stdio.h>
#include <string.h>

char* getStr( char* buffer , int maxRead ) {
  int  numRead  = 0;
  char ch;

  struct termios old = {0};
  struct termios new = {0};
  if( tcgetattr( 0 , &old ) < 0 )        perror( "tcgetattr() old settings" );
  if( tcgetattr( 0 , &new ) < 0 )        perror( "tcgetaart() new settings" );
  cfmakeraw( &new );
  if( tcsetattr( 0 , TCSADRAIN , &new ) < 0 ) perror( "tcssetattr makeraw new" );

  for( int i = 0 ; i < maxRead ; i++)  {
    ch = getchar();
    switch( ch )  {
      case EOF: 
      case '\n':
      case '\r':
        goto exit_getStr;
        break;

      default:
        printf( "%1c" , ch );
        buffer[ numRead++ ] = ch;
        if( numRead >= maxRead )  {
          goto exit_getStr;
        }
        break;
    }
  }

exit_getStr:
  if( tcsetattr( 0 , TCSADRAIN , &old) < 0)   perror ("tcsetattr reset to old" );
  printf( "\n" );   
  return buffer;
}


int main( void ) 
{
  const int maxChars = 20;
  char      stringBuffer[ maxChars+1 ];
  memset(   stringBuffer , 0 , maxChars+1 ); // initialize to 0

  printf( "enter a string: ");
  getStr( stringBuffer , maxChars );
  printf( "you entered: [%s]\n" , stringBuffer );
}

ssinfod对Linux的回答的变体，对我的口味来说稍微干净一些，为wcout和wchar_t实现，并在没有错误的情况下擦除无效字符。

#include <functional>

//For Linux kbhit(). For Windows, use conio.h.
#ifdef __unix__
  #include <sys/ioctl.h> //For FIONREAD.
  #include <termios.h>

  //Call this at program start to setup for kbhit.
  void initTerminalInput()
  {
    //Disable internal buffering.
    std::wcout << std::unitbuf;

    //Turn off line buffering.
    struct termios term;
    tcgetattr(0, &term);
    term.c_lflag &= ~ICANON;
    tcsetattr(0, TCSANOW, &term);
    setbuf(stdin, NULL);
  }

  //Returns 0 if there's no input character to read.
  int kbhit()
  {
    static int nbbytes;
    ioctl(0, FIONREAD, &nbbytes);
    return nbbytes;
  }
#endif

//Waits for and retrieves a single validated character, calling a validation function on each character entered and
//erasing any that are invalid (when the validation function returns false).
static wchar_t getWChar(std::function<bool(wchar_t)> validationFunction)
{
  static wchar_t inputWChar;
  do
  {
    //Wait until there's an input character.
    while (!kbhit())
    {
    }
    inputWChar = getwchar();
    //Validate the input character.
    if (validationFunction(inputWChar))
    {
      //Valid.
      break;
    }
    else
    {
      //Erase the invalid character.
      std::wcout << L"\b \b";
    }
  } while (true);
  return inputWChar;
}

在下面的例子中，我想让用户输入1、2或3。输入的任何其他字符都不会显示，它将等待，直到按下其中一个有效字符:

int main()
{
  #ifdef __unix__
    initTerminalInput();
  #endif

  getWChar([] (wchar_t inputWChar)
  {
    return (inputWChar >= L'1' && inputWChar <= L'3');
  });

  return 0;
}

如果你在windows上，你可以使用PeekConsoleInput来检测是否有任何输入，

HANDLE handle = GetStdHandle(STD_INPUT_HANDLE);
DWORD events;
INPUT_RECORD buffer;
PeekConsoleInput( handle, &buffer, 1, &events );

然后使用ReadConsoleInput“消费”输入字符..

PeekConsoleInput(handle, &buffer, 1, &events);
if(events > 0)
{
    ReadConsoleInput(handle, &buffer, 1, &events);  
    return buffer.Event.KeyEvent.wVirtualKeyCode;
}
else return 0

老实说，这是从一些旧的代码，我有，所以你必须拨弄它一点。

最酷的是它读取输入时没有任何提示，所以字符根本不会显示出来。

我也遇到过同样的问题。这里是一个小的解决方案为windows控制台使用cygwing++与if(GetKeyState(keycode) & bitANDcompare){};

#include <windows.h>
#include <fstream>
#include <iostream>

using namespace std;
void clear() {
    COORD topLeft  = { 0, 0 };
    HANDLE console = GetStdHandle(STD_OUTPUT_HANDLE);
    CONSOLE_SCREEN_BUFFER_INFO screen;
    DWORD written;

    GetConsoleScreenBufferInfo(console, &screen);
    FillConsoleOutputCharacterA(
        console, ' ', screen.dwSize.X * screen.dwSize.Y, topLeft, &written
    );
    FillConsoleOutputAttribute(
        console, FOREGROUND_GREEN | FOREGROUND_RED | FOREGROUND_BLUE,
        screen.dwSize.X * screen.dwSize.Y, topLeft, &written
    );
    SetConsoleCursorPosition(console, topLeft);
}

class Keyclick{
    private:
    int key;
    char id;
    public:
    bool keydown = false;
    Keyclick(int key1, char id1){
        key=key1;
        id=id1;
    };
    void watch(){
        if(keydown==false){
            if(GetKeyState(key) & 0x8000 ){
                cout << id;
                cout << "  pressed.\r\n";
                keydown = true;
            }
        }
        if(keydown == true){
            if(!(GetKeyState(key) & 0x8000)) {
                cout << "released!!!!!!!!!!\r\n";
                keydown = false;
                clear();
            }
        }
    };
};

int main()
{
    bool primaryloop =true;
    Keyclick keysp(VK_SPACE,'S');
    Keyclick keyw(0x57,'w');
    Keyclick keya(0x41,'a');
    Keyclick keys(0x53,'s');
    Keyclick keyd(0x44,'d');
    Keyclick keyesc(VK_ESCAPE,'E');
    
    while(primaryloop){
        keysp.watch();
        keyw.watch();
        keya.watch();
        keys.watch();
        keyd.watch();
        keyesc.watch();
        
        if(keyesc.keydown){
            primaryloop=false;
        };      
    }
    return 0;
}

https://github.com/wark77/windows_console_keypoller/blob/main/getkeystate_SOLUTION01.cpp