Qt我如何检查两个按键事件之间的时间戳差异 [英] qt how i can check difference of timestamp between 2 keypressevent

问题描述

当两个键之间的时间差大于100毫秒时，我正在尝试在两个编辑之间更改焦点.如果每次输入键时都 keyPressed(..)函数，该如何记忆最后一次输入的键?

I'm trying to change focus between two edits when the time difference between 2 keys is greater than 100ms. How can I memorize the last key input if the keyPressed(..) function is every time a key is inputted ?

推荐答案

我不会为此使用 QTime ，因为它取决于系统时钟.我会使用 QElapsedTimer 或 QTimer .

I wouldn't use QTime for this, as it depends on the system clock. I would use QElapsedTimer or QTimer.

带有 QTimer 的示例:

#include <QtWidgets>

class Widget : public QWidget
{
    Q_OBJECT
public:
    Widget(QWidget *parent = nullptr) : QWidget(parent)
    {
        setLayout(new QHBoxLayout);
        layout()->addWidget(&line_edit1);
        layout()->addWidget(&line_edit2);
        focus_timer.setInterval(100);
        focus_timer.setSingleShot(true);
        connect(&line_edit1, &QLineEdit::textEdited, &focus_timer, QOverload<>::of(&QTimer::start));
        connect(&line_edit2, &QLineEdit::textEdited, &focus_timer, QOverload<>::of(&QTimer::start));
        connect(&focus_timer, &QTimer::timeout, this, [&]
        {
            line_edit1.hasFocus() ? line_edit2.setFocus() : line_edit1.setFocus();
        });
    }
private:
    QLineEdit line_edit1;
    QLineEdit line_edit2;
    QTimer focus_timer;
};

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Widget w;
    w.show();
    return a.exec();
}

#include "main.moc"

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