键盘(lv_keyboard)对象是一个特殊的按钮矩阵(lv_btnmatrix),自身实现了按钮(map)映射和其他功能,目的是用于实现一个虚拟键盘将文本写入文本框(lv_textarea)。

1.常用方法

创建keyboard:

lv_obj_t * lv_keyboard_create(lv_obj_t * parent)

关联textarea到keyboard:

void lv_keyboard_set_textarea(lv_obj_t * obj, lv_obj_t * ta)

2.代码实现

static void ta_event_cb(lv_event_t * e)
{
    lv_event_code_t code = lv_event_get_code(e);
    lv_obj_t * ta = lv_event_get_target(e);
    lv_obj_t * kb = lv_event_get_user_data(e);
    if(code == LV_EVENT_FOCUSED) {
        lv_keyboard_set_textarea(kb, ta);
        lv_obj_clear_flag(kb, LV_OBJ_FLAG_HIDDEN);
    }
    if(code == LV_EVENT_DEFOCUSED) {
        lv_keyboard_set_textarea(kb, NULL);
        lv_obj_add_flag(kb, LV_OBJ_FLAG_HIDDEN);
    }
}
void keyboard_1(void)
{
    /*Create a keyboard to use it with an of the text areas*/
    lv_obj_t *kb = lv_keyboard_create(lv_scr_act());
    /*Create a text area. The keyboard will write here*/
    lv_obj_t * ta;
    ta = lv_textarea_create(lv_scr_act());
    lv_obj_align(ta, LV_ALIGN_TOP_LEFT, 10, 10);
    lv_obj_add_event_cb(ta, ta_event_cb, LV_EVENT_ALL, kb);
    lv_textarea_set_placeholder_text(ta, "Hello");
    lv_obj_set_size(ta, 140, 80);
    ta = lv_textarea_create(lv_scr_act());
    lv_obj_align(ta, LV_ALIGN_TOP_RIGHT, -10, 10);
    lv_obj_add_event_cb(ta, ta_event_cb, LV_EVENT_ALL, kb);
    lv_obj_set_size(ta, 140, 80);
}

效果: