Lvgl draw a red Canvas

How-to
23

I’ve taken the simulator (VS Studio)
added this function to LVGL.Simulator.cpp:

#define CANVAS_WIDTH  50
#define CANVAS_HEIGHT  50

void lv_ex_canvas_test (void)
{
    static lv_color_t  cbuf[LV_CANVAS_BUF_SIZE_TRUE_COLOR (CANVAS_WIDTH, CANVAS_HEIGHT)];

    lv_obj_t* canvas = lv_canvas_create (lv_scr_act (), NULL);

    lv_canvas_set_buffer (canvas, cbuf, CANVAS_WIDTH, CANVAS_HEIGHT, LV_IMG_CF_TRUE_COLOR);

    lv_canvas_set_palette (canvas, 1, LV_COLOR_RED);
    lv_obj_align (canvas, NULL, LV_ALIGN_IN_TOP_LEFT, 0, 0);
    lv_canvas_fill_bg (canvas, LV_COLOR_RED, LV_OPA_TRANSP);
}

Changed the lv_conf to this:

/* Maximal horizontal and vertical resolution to support by the library.*/
//#define LV_HOR_RES_MAX          (800)
//#define LV_VER_RES_MAX          (480)

#define LV_HOR_RES_MAX          (320)
#define LV_VER_RES_MAX          (240)

/* Color depth:
 * - 1:  1 byte per pixel
 * - 8:  RGB332
 * - 16: RGB565
 * - 32: ARGB8888
 */
#define LV_COLOR_DEPTH     16

Changed in main (LVGL.Simulator.cpp)

    /*
     * Demos, benchmarks, and tests.
     *
     * Uncomment any one (and only one) of the functions below to run that
     * item.
     */

    lv_ex_canvas_test ();
//    lv_demo_widgets();

and, as expected, I get this when running the simulator:

Simulator

24

would you share the windows simulator you used?maybe we used different windows simulator

25

I use the Visual Studio simulator from here: https://github.com/lvgl/lv_sim_visual_studio.

I did the download today.

26

image
i wnat to make sure about LV_BIG_ENDIAN_SYSTEM setting.
lvgl used little endian by defaukt and if my systerm is big endian,i need to modify to 1,right?

27

Another question:
how to support mutiple language display?

28

would you share a example to display a image?

29

does lvgl support display QR code?

30

This forum supports a forum search function!
Right at the top, the magnifier symbol.

For the QR code you would find the following: QRCODE display with littlevgl
Searching for internationalization (or i18n for short) : Print in other languages

What’s about your simulator problem?
Is your red rectangle example working now?

31

yes,lvgl works fine on my real device now.Thanks

32

i want to select list item by keyboard.when click down key,list item pop.
how to implement it?please give guidance

33

LVGL work on my real device nonw.Thank for your support.Just some function need to implement.

34

when i switch screen,i found new screen load slowly.