（计时时间）分钟刻度检测错误

Question

我的代码中有一个 if 语句，它应该检测我的 chrono::duration 是否超过一分钟的运行时间。当 if 语句变为真时，它应该打印“Tick!” 仅一次，但我的程序会打印“Tick!”每次 delta__time 超过一分钟，即使我从中减去 60 秒。您可能需要查看照片才能更好地了解问题。我仍在努力解释事情，这只是我在网站上的第二篇文章。如何让我的代码每分钟只打印一次刻度？非常感谢。

int main()
{
    // Create Screen Buffer
    wchar_t* screen = new wchar_t[nScreenWidth * nScreenHeight];
    HANDLE hConsole = CreateConsoleScreenBuffer(GENERIC_READ | GENERIC_WRITE, 0, NULL, CONSOLE_TEXTMODE_BUFFER, NULL);
    //SetConsoleActiveScreenBuffer(hConsole);
    DWORD dwBytesWritten = 0;

    wstring numberSystem[10] = {
    };

    while (1)
    {
        tp2 = chrono::system_clock::now();
        chrono::duration<long double, ratio<60>> delta__time = tp2 - tp1;

    if (delta__time >= 60s)
        {
            delta__time -= 60s;
            cout << "Tick!\t" << delta__time.count() << endl;
        }
        else {
            cout << delta__time.count() << endl;
        }
        // Handle change in time here.
    }

    return 0;
}

Chrono time minute tick detection error

Answer 1

正如@drescherjm 所说，您的问题是-= 60s; 被丢弃，因为您每次迭代都会重新计算增量时间。

using namespace std::literals;

auto start_time = std::chrono::system_clock::now();
long ticks = 0;
while (1)
{
  auto current_time = std::chrono::system_clock::now();
  std::chrono::duration<long double, std::ratio<60>> delta_time = current_time - start_time;
  delta_time -= ticks * 60s; // note that `ticks` adds up.

  if (delta_time >= 60s)
  {
    ++ticks;
    std::cout << "Tick!\t" << delta_time.count() << std::endl;
  } else {
    std::cout << delta_time.count() << std::endl;
  }
  // Handle change in time here.
}

我将start_time 保留为未更改的开始时间，current_time 同上，而不是像添加到tp1 一样。它使思考这些变量真正简单。

Answer 2

要关闭这篇文章...我继续往 tp1 变量中添加 60 秒，每发生一分钟的滴答声。谢谢！ :)

这是最终代码。

#include <iostream>
#include <chrono>
using namespace std;

#include <Windows.h>

int nScreenWidth = 240;
int nScreenHeight = 80;

int nMapWidth = 8;
int nMapHeight = 5;

int main()
{
    // Create Screen Buffer
    wchar_t* screen = new wchar_t[nScreenWidth * nScreenHeight];
    HANDLE hConsole = CreateConsoleScreenBuffer(GENERIC_READ | GENERIC_WRITE, 0, NULL, CONSOLE_TEXTMODE_BUFFER, NULL);
    SetConsoleActiveScreenBuffer(hConsole);
    DWORD dwBytesWritten = 0;

    // Current Time
    int hourDoubleDigit = 1;
    int hourSingleDigit = 2;
    int minuteDoubleDigit = 0;
    int minuteSingleDigit = 0;

    // Character Mapping
    wstring numberSystem[10] = {
    };

    numberSystem[0] += L"########"; numberSystem[1] += L"      ##"; numberSystem[2] += L"########";
    numberSystem[0] += L"##   ###"; numberSystem[1] += L"      ##"; numberSystem[2] += L"      ##";
    numberSystem[0] += L"## ## ##"; numberSystem[1] += L"      ##"; numberSystem[2] += L"########";
    numberSystem[0] += L"###   ##"; numberSystem[1] += L"      ##"; numberSystem[2] += L"##      ";
    numberSystem[0] += L"########"; numberSystem[1] += L"      ##"; numberSystem[2] += L"########";

    numberSystem[3] += L"########"; numberSystem[4] += L"##    ##"; numberSystem[5] += L"########";
    numberSystem[3] += L"      ##"; numberSystem[4] += L"##    ##"; numberSystem[5] += L"##      ";
    numberSystem[3] += L"########"; numberSystem[4] += L"########"; numberSystem[5] += L"########";
    numberSystem[3] += L"      ##"; numberSystem[4] += L"      ##"; numberSystem[5] += L"      ##";
    numberSystem[3] += L"########"; numberSystem[4] += L"      ##"; numberSystem[5] += L"########";

    numberSystem[6] += L"########"; numberSystem[7] += L"########"; numberSystem[8] += L"########"; numberSystem[9] += L"########";
    numberSystem[6] += L"##      "; numberSystem[7] += L"      ##"; numberSystem[8] += L"##    ##"; numberSystem[9] += L"##    ##";
    numberSystem[6] += L"########"; numberSystem[7] += L"      ##"; numberSystem[8] += L"########"; numberSystem[9] += L"########";
    numberSystem[6] += L"##    ##"; numberSystem[7] += L"      ##"; numberSystem[8] += L"##    ##"; numberSystem[9] += L"      ##";
    numberSystem[6] += L"########"; numberSystem[7] += L"      ##"; numberSystem[8] += L"########"; numberSystem[9] += L"########";

    // Keeping Track of System Time
    auto tp1 = chrono::system_clock::now();
    auto tp2 = chrono::system_clock::now();

    auto TickInterval = 60s;

    while (1)
    {
        for (int xy = 0; xy <= nScreenWidth * nScreenHeight; xy++) screen[xy] = ' ';//To prevent buggy character spawning...
        // You don't always have to write this above line if you're already making use of writing characters to every space in the screen, but I'm not!


        // Let the program know a minute has passed... (Time passes too much too often)
        tp2 = chrono::system_clock::now();
        chrono::duration<long double> delta__time = tp2 - tp1;
        bool TICKhasOCCURED = false;

        if (delta__time >= TickInterval)
        {
            tp1 += TickInterval;
            TICKhasOCCURED = true;
        }

        if (TICKhasOCCURED)
        {
            if (minuteSingleDigit >= 9)
            {
                if (minuteDoubleDigit >= 5)
                {

                    if (hourSingleDigit >= 9 && hourDoubleDigit == 0)
                    {
                        hourDoubleDigit++;
                        hourSingleDigit = 0;
                        minuteDoubleDigit = 0;
                        minuteSingleDigit = 0;
                    }
                    else if (hourSingleDigit >= 2 && hourDoubleDigit == 1)
                    {
                        hourDoubleDigit = 0;
                        hourSingleDigit = 1;
                        minuteDoubleDigit = 0;
                        minuteSingleDigit = 0;

                    }
                    else {
                        hourSingleDigit++;
                        minuteDoubleDigit = 0;
                        minuteSingleDigit = 0;
                    }//After 59 minutes check the hour and change it.
                }
                else {
                    minuteDoubleDigit++;
                    minuteSingleDigit = 0;
                }
            }
            else {
                minuteSingleDigit++;
            }
        }


        // The Current Time is then drawn out using the mapped characters.
        for(int ix = 0; ix < nMapWidth; ix++)
            for (int iy = 0; iy < nMapHeight; iy++)
            {
                screen[00 + ix + (nScreenWidth * iy)] = numberSystem[hourDoubleDigit][ix + (nMapWidth * iy)];
                screen[10 + ix + (nScreenWidth * iy)] = numberSystem[hourSingleDigit][ix + (nMapWidth * iy)];
                screen[20 + ix + (nScreenWidth * iy)] = numberSystem[minuteDoubleDigit][ix + (nMapWidth * iy)];
                screen[30 + ix + (nScreenWidth * iy)] = numberSystem[minuteSingleDigit][ix + (nMapWidth * iy)];
            }


        //Debug
        //cout << hourDoubleDigit << "\t" << hourSingleDigit << "\t" << minuteDoubleDigit << "\t" << minuteSingleDigit << endl;
        TICKhasOCCURED = false;

        screen[nScreenWidth * nScreenHeight-1] = '\0';
        WriteConsoleOutputCharacter(hConsole, screen, nScreenWidth * nScreenHeight, { 0,0 }, &dwBytesWritten);
    }

    return 0;
}

Answer 3

delta__time 在每次循环迭代开始时都会重新计算，因此对其进行的更改不会产生任何持久影响（尽管它确实会影响紧随其后的cout，这就是您的值看起来很低的原因）。

您可能希望将 60s 添加到 tp1（或将其设置为 now()，尽管这会导致错误）。