C++ 如何使用 ESC 按钮终止我的程序

Question

这是我使用 visual studio 2012 express 的主要功能，代码运行良好。我的问题是，当用户按下 ESC 按钮而不是 -1 时，我将如何终止此循环。虽然我更喜欢在 unix 和 windows 中都适用的解决方案，但如果不可能的话，我最感兴趣的是它在 windows 上的工作。

int _tmain(int argc, _TCHAR* argv[])
{
list mylist;

int value;
cout<<"Give the numbers you want to insert to the list, press -1 to stop\n";
do
{
    cin>>value;
    mylist.insertf(value);
    mylist.sort_list();
    mylist.print();
}while(value!=-1);




}

Answer 1

这是 Windows 的解决方案

第一个解决方案:

当用户开始输入直到按下 enter 时，Esc 将不会被处理。空闲时 Esc 将被处理

#include <Windows.h>
#include <iostream>
#include <conio.h>
#include <vector>
int main(int argc, char **argv)
{
    int value=0;
    std::vector<int> mylist; 
    do
    {   
        //check if any input.
        if (_kbhit()){
            //probable user started to type 
            //block to read till the user press Enter. If you want to handle Esc here .
            //then you should manually do input reading . I will write that solution later
            std::cin>>value; 
            //if success
            if(std::cin.good()){ 
                mylist.push_back(value); 
            }else{
                //firstly, clear error flag 
                std::cin.clear();
                //ignore 
                std::cin.ignore(10000,'\n');

            }

            //print  list
            std::cout<<"new list: { " ;
            for(int i=0;i< mylist.size();i++){
                std::cout<<mylist[i]<<'\t';
            }
            std::cout<<" }"<<std::endl;
        }

        //check if Esc Pressed
    }while(GetAsyncKeyState(VK_ESCAPE)==0);

    return 0;
}

第二种解决方案:

Esc 将始终在另一个线程中处理。在某些情况下可能不希望立即退出

DWORD WINAPI CheckEscape( LPVOID lpParam ) {
        while(GetAsyncKeyState(VK_ESCAPE)==0){
            //sleep 
            Sleep(10);
        }
        exit(0);

}



int main(int argc, char **argv)
{
    int value=0;
    std::vector<int> mylist; 
    //create thread for handling ESC key
    CreateThread( NULL, 0, CheckEscape,NULL  , 0, NULL);

    //loop infinitely
    while(true)
    {    
            std::cin>>value; 
            //if success
            if(std::cin.good()){ 
                mylist.push_back(value); 
            }else{
                //firstly, clear error flag 
                std::cin.clear();
                //ignore 
                std::cin.ignore(10000,'\n');

            }

            //print  list
            std::cout<<"new list: { " ;
            for(int i=0;i< mylist.size();i++){
                std::cout<<mylist[i]<<'\t';
            }
            std::cout<<" }"<<std::endl;
        }  
    return 0;
}

第三种解决方案和最佳解决方案。手动完成所有操作

手动处理按键。按下 Esc 时将调用 Exit。您可以更改它以处理更正确的方式

bool keypress( char &key){
    INPUT_RECORD IR[1];
    DWORD read;
    static HANDLE h = GetStdHandle(STD_INPUT_HANDLE);
    while(PeekConsoleInputA(h,IR,1,&read)){
        if(read!=0){
            //check if it was Key Event
            if(IR[0].EventType==KEY_EVENT){
                key=IR[0].Event.KeyEvent.uChar.AsciiChar; 
                ReadConsoleInputA(h,IR,1,&read);
                FlushConsoleInputBuffer(h);
                return true;
            }
            if(ReadConsoleInputA(h,IR,1,&read)){
                continue; 
            }
        }else{
            return false;
        }
    }
}

//getnumber
int cinnumb( ){
    char buffer[32];
    buffer[0]='\0';
    int count=0;
    DWORD key=-1;
    while(true){

        Sleep(100);
        do{
            //here I make it nonblockin keypress
            //but actually we do not need it 
            //we can use blocking ReadConsoleInputA(h,IR,1,&read);
            //this way we not even need sleep() and 
            //our keypress function will be simple
            //anyway im posting nonblocking one

            //nonblocking keypress
            char key=0;
            bool isOk=keypress(key );

            if(!isOk ){ 
                Sleep(20);
                continue;
            }

            if(key>='0' && key<='9'){
                buffer[count]=key; 
                std::cout<<key;
                ++count;
                if( count==31)break;

            }

            // check Enter key and  enough symbol
            if(  key==13 && count>0  ){  
                std::cout<<std::endl;
                break;
            }

            //for windows 

            //check if Esc pressed
            if(key==27) exit(0); 


        }while(true);

        buffer[count]='\0';

        int value=atoi(buffer);
        return value;
    }
}
int main(int argc, _TCHAR* argv[])
{
    std::vector<int> mylist; 
    int value; 
    char buffer[100];
    //infinite loop
    while(true)
    {   
        //get number 
        value=cinnumb(); 
        mylist.push_back(value);
         //print  list
        std::cout<<"new list: { " ;
        for(int i=0;i< mylist.size();i++){
                std::cout<<mylist[i]<<'\t';
            }
        std::cout<<" }"<<std::endl;
        //sleep a little
        Sleep(10); 
    } ;


    return 0;

}