Can't add userdata to event callback

How-to
1

Description

I would like to add userdata to the event. However, the user data is always transmitted incorrectly.

What MCU/Processor/Board and compiler are you using?

Arduino Due / Arduino IDE

What LVGL version are you using?

V8.0

What do you want to achieve?

The user data correctly transferred to the event callback function

What have you tried so far?

I tried to transfer user data via LVGL functions. When reading out the data does not match the original data that I sent. I send an Integer like 10001 but when i print the receive userdata it is something like 5344554.

Code to reproduce

The code block(s) should be formatted like:

          int tmp_numpad_userdata;
          tmp_numpad_userdata = channel * 10000 + current_frame * 100 + current_signal;
         
 lv_obj_add_event_cb(labelReihe1[current_signal + output_config_send_data_offset][1], my_event_cb_NUM_Pad, LV_EVENT_CLICKED, &tmp_numpad_userdata); 

// and the cb function

static void my_event_cb_NUM_Pad(lv_event_t * e)
{
  int * userdata = (int *)lv_event_get_user_data(e);
  //int userdata2 = int(*userdata)
  //int *pInt = static_cast<int*>(lv_event_get_user_data(e));
  log_newline();
  log_item("Übergabeparameter ist  ");
  log_item(* userdata);
  log_newline();
}
2

What is

int tmp_numpad_userdata;

?
Is this local or global variable?

3

Oh yeah sry for this. It’s a local Variable.

4

What if you made it global or static local?

5

The solution is to declare the userdata to be transferred as a define.
If i want transfer a struct as userdata i have to do it that way:

struct TMP_numpad_userdata
  {
    byte channel;
    byte frame;
    byte signaL;
  };

 typedef TMP_numpad_userdata  lv_obj_user_data_t;

Now i can use this struct to transfer userdata.