hi

back color of ComboBox in DataGridView will change to black when selectedindex change event will finish and focus on next cell

my code:

private void _dgv_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
        {
            if (_dgv.CurrentRow != null)
            {
                ComboBox col1Combo = e.Control as ComboBox;
                if (col1Combo != null)
                {
                    if (_dgv.CurrentCell.ColumnIndex == 1)
                    {
                        col1Combo.SelectedIndexChanged += col1Combo_SelectedIndexChanged;
                    }
                }
            }
        }
        private void col1Combo_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (_dgv.CurrentCell.ColumnIndex == 1)
            {
                DataGridViewComboBoxCell Column_ModemList = (DataGridViewComboBoxCell)this._dgv.CurrentRow.Cells[2];
                Column_ModemList.Items.Clear();

                

                _dgv.CommitEdit(DataGridViewDataErrorContexts.Commit);

                ((ComboBox)sender).BackColor = Color.white;
                if (_dgv.CurrentCell.EditedFormattedValue.ToString() == "aa")
                {
                    Column_ModemList.Items.Add("bb");
                    Column_ModemList.Items.Add("cc");
                }
                else if (_dgv.CurrentCell.EditedFormattedValue.ToString() == "hh")
                {
                    Column_ModemList.Items.Add("ss");
                }
                else if (_dgv.CurrentCell.EditedFormattedValue.ToString() == "fff")
                {
                    Column_ModemList.Items.Add("rrr");
                }
                ((ComboBox)sender).BackColor = Color.white;
                _dgv.CurrentCell.Style.BackColor = System.Drawing.Color.white;
            }
        }

        private void _dgv_CurrentCellDirtyStateChanged(object sender, EventArgs e)
        {
            if (_dgv.IsCurrentCellDirty)
            {
                _dgv.CommitEdit(DataGridViewDataErrorContexts.Commit);
            }
        }

        private void _dgv_CellValueChanged(object sender, DataGridViewCellEventArgs e)
        {
            if (e.RowIndex >= 0)
            {
                _dgv.CurrentCell.Style.BackColor = System.Drawing.Color.white;
            }
        }