c++ - 在 C++ gtk::drawarea 中:如何刷新图像

Question

我在 C++ 中使用 gtkmm 作为 GUI。我有一个 Gtk::DrawingArea，上面有一张图片(文件名):

class MyArea : public Gtk::DrawingArea
{
public:
    MyArea(string filename)
    {
        m_image = Gdk::Pixbuf::create_from_file(filename.c_str());
    }

    virtual bool on_draw(const Cairo::RefPtr<Cairo::Context>& cr)
    {
        if (!m_image)
            return false;

        Gtk::Allocation allocation = get_allocation();
        const int width  = allocation.get_width();
        const int height = allocation.get_height();

        // Draw the image in the middle of the drawing area, or (if the image is
        // larger than the drawing area) draw the middle part of the image.
        Gdk::Cairo::set_source_pixbuf(cr, m_image, (width - m_image->get_width())/2, (height - m_image->get_height())/2);
        cr->paint();

        return true;
    }
    Glib::RefPtr<Gdk::Pixbuf> m_image;
}

我想要一个改变图像的函数(使用 filename2)。但我找不到如何:-/

有人可以帮我解决这个问题吗？谢谢你

Answer 1

作为类(class)成员:

void change_image(string filename2)
{
    m_image = Gdk::Pixbuf::create_from_file(filename2.c_str());
    queue_draw();
}