C++ 如何在C++；在给定时间内获取用户输入？

我需要用户输入在一定时间范围内按下一个键。如果他不按任何键，则秒变量递增。下面您可以找到流程图和我的代码

int DisplayMenu（）//此函数显示用户菜单。
{
int userChoice{}；
cout您可以计算用户输入字符所需的秒数：

int DisplayMenu() //This function displays the user menu.
{
    int userChoice{};
    cout << "\t\t***************************" << endl;
    cout << "\t\t* 1-Add One Hour          *" << endl;
    cout << "\t\t* 2-Add One Minute        *" << endl;
    cout << "\t\t* 3-Add One Second        *" << endl;
    cout << "\t\t* 4-Exit Program          *" << endl;
    cout << "\t\t***************************" << endl;
    std::chrono::timepoint before = std::chrono::high_resolution_clock::now();
    cin >> userChoice;
    std::chrono::timepoint after = std::chrono::high_resolution_clock::now();
    seconds += std::chrono::floor<std::chrono::seconds>(after - before).count();
    return userChoice; //The value returned will be use as argument for the UserChoice function.
}

或者，您可以在单独的线程中运行递增的
秒数。
您可以计算用户输入字符所需的秒数：

int DisplayMenu() //This function displays the user menu.
{
    int userChoice{};
    cout << "\t\t***************************" << endl;
    cout << "\t\t* 1-Add One Hour          *" << endl;
    cout << "\t\t* 2-Add One Minute        *" << endl;
    cout << "\t\t* 3-Add One Second        *" << endl;
    cout << "\t\t* 4-Exit Program          *" << endl;
    cout << "\t\t***************************" << endl;
    std::chrono::timepoint before = std::chrono::high_resolution_clock::now();
    cin >> userChoice;
    std::chrono::timepoint after = std::chrono::high_resolution_clock::now();
    seconds += std::chrono::floor<std::chrono::seconds>(after - before).count();
    return userChoice; //The value returned will be use as argument for the UserChoice function.
}

或者您可以在单独的线程中运行
seconds
递增