LVGL 8.2 Checkboxes as radio buttons

Variable definitions

static lv_style_t style_radio;
static lv_style_t style_radio_chk;
static uint32_t active_index_1 = 0;
static uint32_t active_index_2 = 0;

Event handling callback function

static void radio_event_handler(lv_event_t* e)
{
    
    uint32_t* active_id = lv_event_get_user_data(e); // Get user data 
    lv_obj_t* cont = lv_event_get_current_target(e); //  Get the layout object of the current target event 
    lv_obj_t* act_cb = lv_event_get_target(e);// Get the object that generated the event 
    lv_obj_t* old_cb = lv_obj_get_child(cont, *active_id); // according to id Sequence number get sub object 
    /*Do nothing if the container was clicked*/
    if (act_cb == cont) return; // Don't deal with layout Events generated by layout objects 
    lv_obj_clear_state(old_cb, LV_STATE_CHECKED); // Clear previous selection status 
    lv_obj_add_state(act_cb, LV_STATE_CHECKED); //  Set the clicked object as selected 
    *active_id = lv_obj_get_index(act_cb); // Get the... Of the selected object id Serial number and save in active_id In the memory pointed to 
    LV_LOG_USER("Selected radio buttons: %d, %d", (int)active_index_1, (int)active_index_2); // Print active_index_1,active_index_2
}

radio establish

static void radiobutton_create(lv_obj_t* parent, const char* txt)
{
    
    lv_obj_t* obj = lv_checkbox_create(parent);  // stay parent Create on object checkbox object 
    lv_checkbox_set_text(obj, txt);  //  Set the text to txt What's in the pointer 
    lv_obj_add_flag(obj, LV_OBJ_FLAG_EVENT_BUBBLE); //  add to LV_OBJ_FLAG_EVENT_BUBBLE sign 
    lv_obj_add_style(obj, &style_radio, LV_PART_INDICATOR); //obj Object's LV_PART_INDICATO The Properties section uses style_radio
    lv_obj_add_style(obj, &style_radio_chk, LV_PART_INDICATOR | LV_STATE_CHECKED); // obj Object's LV_PART_INDICATO and LV_STATE_CHECKED The Properties section uses style_radio_chk
}

Checkboxes as radio buttons

/** * Checkboxes as radio buttons */
static void lv_example_checkbox_2(void)
{
    
    /* The idea is to enable `LV_OBJ_FLAG_EVENT_BUBBLE` on checkboxes and process the * `LV_EVENT_CLICKED` on the container. * A variable is passed as event user data where the index of the active * radiobutton is saved */
    lv_style_init(&style_radio);  // Initial timing style_radio
    lv_style_set_radius(&style_radio, LV_RADIUS_CIRCLE); // Set chamfer to circular 
    lv_style_init(&style_radio_chk); // Initial timing style_radio_chk
    lv_style_set_bg_img_src(&style_radio_chk, NULL); // Set the background icon resource to NULL
    uint32_t i;
    char buf[32];
    lv_obj_t* cont1 = lv_obj_create(lv_scr_act());  // Create an object for layout
    lv_obj_set_flex_flow(cont1, LV_FLEX_FLOW_COLUMN);// Set the layout to LV_FLEX_FLOW_COLUMN The way 
    lv_obj_set_size(cont1, lv_pct(40), lv_pct(80)); // Set size 
    lv_obj_add_event_cb(cont1, radio_event_handler, LV_EVENT_CLICKED, &active_index_1); //  add to LV_EVENT_CLICKED event , User defined data is active_index_1
    for (i = 0; i < 5; i++) {
    
        lv_snprintf(buf, sizeof(buf), "A %d", (int)i + 1);
        radiobutton_create(cont1, buf);  // Co created 5 individual radio Key 
    }
    /*Make the first checkbox checked*/
    lv_obj_add_state(lv_obj_get_child(cont1, 0), LV_STATE_CHECKED); // Select the first 1 individual radio
    lv_obj_t* cont2 = lv_obj_create(lv_scr_act()); // Create an object for layout
    lv_obj_set_flex_flow(cont2, LV_FLEX_FLOW_COLUMN);// Set the layout to LV_FLEX_FLOW_COLUMN The way 
    lv_obj_set_size(cont2, lv_pct(40), lv_pct(80)); // Set size 
    lv_obj_set_x(cont2, lv_pct(50)); // Set up cont2 Layout x The position is screen mu 50% It's about 
    lv_obj_add_event_cb(cont2, radio_event_handler, LV_EVENT_CLICKED, &active_index_2);//  add to LV_EVENT_CLICKED event , User defined data is active_index_2
    for (i = 0; i < 3; i++) {
    
        lv_snprintf(buf, sizeof(buf), "B %d", (int)i + 1);
        radiobutton_create(cont2, buf);  // Co created 3 individual radio Key 
    }
    /*Make the first checkbox checked*/
    lv_obj_add_state(lv_obj_get_child(cont2, 0), LV_STATE_CHECKED);// Select the first 1 individual radio
}

Running effect

take radiobutton_create Function lv_obj_add_flag Comment out

static void radiobutton_create(lv_obj_t* parent, const char* txt)
{
    
    lv_obj_t* obj = lv_checkbox_create(parent);
    lv_checkbox_set_text(obj, txt);
  // lv_obj_add_flag(obj, LV_OBJ_FLAG_EVENT_BUBBLE);
    lv_obj_add_style(obj, &style_radio, LV_PART_INDICATOR);
    lv_obj_add_style(obj, &style_radio_chk, LV_PART_INDICATOR | LV_STATE_CHECKED);
}

Running effect