c# - Masking password column in datagridview

Question

I'm having problem with masking the password column. The code below works, but it doesnt work the way I want. While editing it do mask the password but when I am done and continue to the next datagridviewcell password becomes visible.

private void dataGridView1_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
{            
        if (  dataGridView1.CurrentCell.ColumnIndex == 5 || dataGridView1.CurrentCell.ColumnIndex == 10)//select target column
        {
            TextBox textBox = e.Control as TextBox;
            if (textBox != null)
            {
                textBox.UseSystemPasswordChar = true;
            }                
        }
        var txtBox = e.Control as TextBox;
        txtBox.KeyDown -= new KeyEventHandler(underlyingTextBox_KeyDown);
        txtBox.KeyDown += new KeyEventHandler(underlyingTextBox_KeyDown);
}

Also in edit mode it should have mask only the columns with index 5 && 10 however it masks all columns. I cannot solve these issues, any help would be great.

Answer 1

    private void dataGridView1_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
    {
        if ((e.ColumnIndex == 5 || e.ColumnIndex == 10) && e.Value != null)
            {
                dataGridView1.Rows[e.RowIndex].Tag = e.Value;
                e.Value = new String('u25CF', e.Value.ToString().Length);
            }
    }

    private void dataGridView1_EditingControlShowing(object sender, DataGridViewEditingControlShowingEventArgs e)
    {
        if (dataGridView1.CurrentCell.ColumnIndex == 5 || dataGridView1.CurrentCell.ColumnIndex == 10)//select target column
        {
            TextBox textBox = e.Control as TextBox;
            if (textBox != null)
            {
                textBox.UseSystemPasswordChar = true;
            }
        }
        else
        {
            TextBox textBox = e.Control as TextBox;
            if (textBox != null)
            {
                textBox.UseSystemPasswordChar = false;
            }
        }
        var txtBox = e.Control as TextBox;
        txtBox.KeyDown -= new KeyEventHandler(underlyingTextBox_KeyDown);
        txtBox.KeyDown += new KeyEventHandler(underlyingTextBox_KeyDown);
    }