private void cmbStdUnit1_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;
}
}