Qt Border Width & Color Styling

In Qt, you can set the border width and color by using style sheets. Here is an example code demonstrating how to set the border width of a QWidget to 2px and color to red:

#include <QtWidgets>

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);

    QWidget widget;
    widget.resize(200, 200);

    widget.setStyleSheet("QWidget { border: 2px solid red; }");

    widget.show();

    return app.exec();
}

In the example above, we used the setStyleSheet method to set the style sheet for a QWidget. In the style sheet, we defined a border property that sets the border width to 2px and the color to red. You can adjust the width and color as needed to achieve different effects.