thank you. every thing is ok now.

code is here , and I hve change default_kb_ctrl_lc_map for “ABC” to LV_KEYBOARD_CTRL_BTN_FLAGS | 7
lv_obj_set_style_local_pad_inner(kb1, LV_BTNMATRIX_PART_BG, LV_STATE_DEFAULT, 0);
lv_obj_set_style_local_border_width(kb1, LV_BTNMATRIX_PART_BG, LV_STATE_DEFAULT, 0);
lv_obj_set_style_local_border_width(kb1, LV_BTNMATRIX_PART_BTN, LV_STATE_DEFAULT, 0);
static const lv_btnmatrix_ctrl_t default_kb_ctrl_lc_map[] = {
LV_KEYBOARD_CTRL_BTN_FLAGS | 5, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 7,
LV_KEYBOARD_CTRL_BTN_FLAGS | 7, 3, 3, 3, 3, 3, 3, 3, 3, 3, 6,
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
LV_KEYBOARD_CTRL_BTN_FLAGS | 2, 2, 6, 2, LV_KEYBOARD_CTRL_BTN_FLAGS | 2
};