请教datagridtextboxcolumn的问题？

Question

DataGridTableStyle style=new DataGridTableStyle();
style.MappingName="Quotation"; DataGridTextBoxColumn quotationid=new DataGridTextBoxColumn();   //DataGridTextBoxColumn
quotationid.HeaderText="报价单号";
quotationid.MappingName="QuotationID";
quotationid.Width=100;
quotationid.ReadOnly=true;

                           //DataGridBoolColumn 
DataGridBoolColumn ispass=new DataGridBoolColumn();
ispass.HeaderText="审核";
ispass.MappingName="IsPass";
ispass.Width=50;
ispass.ReadOnly=false;
ispass.AllowNull = false;                            ...................
                             style.GridColumnStyles.AddRange(new DataGridColumnStyle[]
{quotationid,ispass,employee,customer,contactor,quotationdate,memo}); dataGridQuotation.TableStyles.Add(style);