ATMLCommonLibrary.controls.StandardUnitControl.cmbPrefix1_SelectedIndexChanged C# (CSharp) Method

        private void cmbPrefix1_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (!Initializing)
            {
                var sb = new StringBuilder();
                var spBean = cmbPrefix.SelectedItem as StandardUnitPrefixBean;
                var sumBean = cmbStdUnit.SelectedItem as StandardUnitMeasurementBean;
                if (spBean != null)
                    sb.Append(spBean.symbol);
                if (sumBean != null)
                    sb.Append(sumBean.symbol);
                edtStnUnit.Text = sb.ToString();
                edtStnUnit.SelectionStart = edtStnUnit.TextLength;
                edtStnUnit.SelectionLength = 0;
            }
        }