How to uncheck checkedListBox1 and write the string properly?

See more:

C#

string

check

CheckBoxList

I have checkedListBox1 control. I want to write into a string "checked3487", ONLY the checked checkboxes text. (the text near the checkbox).
When I press one checkbox, "The check state is not updated until after the ItemCheck event occurs", but the "if (e.NewValue == CheckState.Checked)" is updating in realtime the check state, but only for the Checked state.
When I UNCHECK, it is updating after 2 click of the mouse, (after the ItemCheck event occurs).
How to uncheck and write the string properly?

Ive searched on google, I done 10 different variants of coding, and im desperate. What I miss?

string checked3487 = ""; List<string> checkedList = new List<string>();
private void checkedListBox1_ItemCheck(object sender, ItemCheckEventArgs e)
      {
          listBox1.Items.Clear(); checked3487 = ""; checkedList.Clear();

          foreach (var item in checkedListBox1.CheckedItems)
              checkedList.Add(item.ToString());

          if (e.NewValue == CheckState.Checked)
          {
              checkedList.Add(checkedListBox1.Items[e.Index].ToString());
          }
          if (e.NewValue == CheckState.Unchecked)
          {
              //?????????????????????????????????????????????????????????????????????/
          }



          foreach (string item in checkedList)
          {
              checked3487 += item;
          }
       }