DataGridViewComboBoxColumn的使用

using  System;
using  System.Collections.Generic;
using  System.ComponentModel;
using  System.Data;
using  System.Data.SqlClient;
using  System.Drawing;
using  System.Text;
using  System.Windows.Forms;

namespace  Sys
{
     public   partial   class  Form3 : Form
    {
         public  Form3()
        {
            InitializeComponent();
        }

         private   void  Form3_Load( object  sender, EventArgs e)
        {
            dataGridView1.AllowUserToAddRows  =   false ;
            dataGridView1.AutoGenerateColumns  =   false ;

             using  (SqlConnection sqlconn  =   new  SqlConnection( " server=.;uid=sa;pwd=sa;database=xx " ))
            {
                 string  sql1  =   @" select userid,fullname,a.[description],b.ugroupid
                                from users a left outer join usergroup b 
                                on a.grade=b.ugroupid " ;
                 string  sql2  =   " select distinct ugroupid,[description] from usergroup " ;

                DataGridViewComboBoxColumn dgvComboBoxColumn  =  dataGridView1.Columns[ " grade " ]  as  DataGridViewComboBoxColumn;
                dgvComboBoxColumn.DataPropertyName  =   " ugroupid " ;
                dgvComboBoxColumn.DataSource  =  GetTable(sql2).DefaultView; // 必须在设置dataGridView1的DataSource的属性前设置
                dgvComboBoxColumn.DisplayMember  =   " description " ;
                dgvComboBoxColumn.ValueMember  =   " ugroupid " ;

                dataGridView1.DataSource  =  GetTable(sql1).DefaultView; // 一定要在dgvComboBoxColumn的DataSource后设置
            }
        }

         private  DataTable GetTable( string  sql)
        {
             using  (SqlConnection sqlconn  =   new  SqlConnection( " server=.;uid=sa;pwd=yuling1310;database=smls " ))
            {
                DataTable dt  =   new  DataTable();
                SqlDataAdapter sqlda  =   new  SqlDataAdapter(sql, sqlconn);
                sqlda.Fill(dt);
                 return  dt;
            }
        }
    }
}

注意事项：
.注意其ValueMember的DataType与DataPropertyName对应的列的DataType要相同，他不会为你做类型转换的。
2.编程设置显示样式时注意一定要在设置DataSource 之前设置DataGridViewComboBoxColumn的DataSource等属性。