如何保持程序运行

Question

I want my code to keep on running without exiting. Is there a way to do this, or do I have to use an infinite loop to keep it running.

#include <iostream>
#include <windows.h>
#include <chrono>
#include <thread>
#include <math.h>
#include <random>
#include <fstream>
using namespace std;

int main()
{
    POINT coord;
    GetCursorPos(&coord);
    fstream file;
    file.open("example.txt", ios::out | ios::in);


    // Reding from file
    

    //closing the file
    int xCoord;
    int yCoord;
    
    GetCursorPos(&coord);
    
    if (MOUSEEVENTF_LEFTDOWN) {
        cout << "Coords: " << coord.x << " , " << coord.y << "\n";
            xCoord = coord.x;
            yCoord = coord.y;
            file << xCoord << "," << yCoord << endl;
    }
   

   

    return 0;
}

Basically, the idea is to log every left click a user has done and put them in a text file, but it just ends after getting one iteration. Is there a way for it to take more than 1 iteration? I've tried using a for infinite loop, but it just floods the whole file with the same coordinates.

Answer 1

I would use while(!GetAsyncKeystate(VK_END)) to keep the code running however for this to work as intended you want to also change if(MOUSEEVENTF_LEFTDOWN) to if (GetAsyncKeyState(VK_LBUTTON )) {

So your code would now look like

    int xCoord;
    int yCoord;
    while (!GetAsyncKeyState(VK_END)) {
    GetCursorPos(&coord);
 

        if (GetAsyncKeyState(VK_LBUTTON ) & 1) {
            cout << "Coords: " << coord.x << " , " << coord.y << "\n";
            xCoord = coord.x;
            yCoord = coord.y;
            file << xCoord << "," << yCoord << endl;
        }
    }
}

When you press the END key on your keyboard your program will stop:3

Answer 2

The problem here is that MOUSEEVENTF_LEFTDOWN is a constant value. This documentation says the value is 0x0002 .

This means that:

if (MOUSEEVENTF_LEFTDOWN)  // this is always true.
                          

So if you add a loop this if condition is always true so it will record a value every iteration of the loop. You need to find a function that returns the state of the mouse button.