Qtimer迭代次数

Question

也许我想得太多了，但是在迭代和qtimer方面需要一些帮助。我有以下QTimer代码和函数(我已经尽可能地简化它，如果某些语法错误，很抱歉)：

    QTimer *timer = new QTimer(this);
    connect(timer, SIGNAL(timeout()), this, SLOT(whateverfunction()));
    timer -> start();

void MainWindow::whateverfunction()
{
checksomething();
if (checksomething() == 1)
{
dosomething1(); //function I want to run ONLY the first time checksomething() = 1
dosomething2(); //function I want to run the second,third,fourth,etc. time checksomething() = 1
}
else
{
donothing(); //if this function is run the count resets, meaning dosomething1() should be run again if checksomething() == 1 again-- but only the first time.
}
}

我怎样才能做到这一点呢？我曾尝试引入一个控制变量，但每次通过QTimer运行此函数时，它都会重置。谢谢!

Answer 1

我建议使用std::call_once包装对dosomething1()的调用

std::once_flag flag;

void MainWindow::whateverfunction()
{
checksomething();
if (checksomething() == 1)
{
    std::call_once(flag, [this](){
        dosomething1();
    };
    dosomething2();
}
}