System.Windows.Forms.ComboBox.OnSelectedItemChanged C# (CSharp) Method

		protected virtual void OnSelectedItemChanged (EventArgs e)
		{
		}

            internal void SetItemInternal(int index, object value)
            {
                if (index < 0 || index >= Count)
                {
                    throw new ArgumentOutOfRangeException(nameof(index), index, string.Format(SR.InvalidArgument, nameof(index), index));
                }

                InnerList[index].Item = value ?? throw new ArgumentNullException(nameof(value));

                // If the native control has been created, and the display text of the new list item object
                // is different to the current text in the native list item, recreate the native list item...
                if (_owner.IsHandleCreated)
                {
                    bool selected = (index == _owner.SelectedIndex);

                    if (string.Compare(_owner.GetItemText(value), _owner.NativeGetItemText(index), true, CultureInfo.CurrentCulture) != 0)
                    {
                        _owner.NativeRemoveAt(index);
                        _owner.NativeInsert(index, value);
                        if (selected)
                        {
                            _owner.SelectedIndex = index;
                            _owner.UpdateText();
                        }

                        if (_owner.AutoCompleteSource == AutoCompleteSource.ListItems)
                        {
                            _owner.SetAutoComplete(false, false);
                        }
                    }
                    else
                    {
                        // NEW - FOR COMPATIBILITY REASONS
                        // Minimum compatibility fix
                        if (selected)
                        {
                            _owner.OnSelectedItemChanged(EventArgs.Empty);   //we do this because set_SelectedIndex does this. (for consistency)
                            _owner.OnSelectedIndexChanged(EventArgs.Empty);
                        }
                    }
                }
            }