获取显示器个数，以及每个显示器的分辨率和位置

    GdkScreen* sc1 =  gdk_screen_get_default();

    gint nm = gdk_screen_get_n_monitors (sc1);

    int i = 0;
    if(nm == 2)
    {   
        for (i = 0; i < nm; i++)
        {   
            GdkRectangle rect;
            gdk_screen_get_monitor_geometry (sc1, i, &rect);

            printf("%d x %d y %d w %d h %d\n", i, rect.x, rect.y, rect.width, rect.height); 
        }   
    }