private void dgvNeed_CellEnter(object sender, DataGridViewCellEventArgs e)
        {
            if (e.ColumnIndex == 1)
            {
                ChoosePart cp = new ChoosePart();
                //this.Visible = false;
                cp.ShowDialog();
                //在这动态绑定一下就哦了。。 dgvNeed.Rows[e.RowIndex].Cells[e.ColumnIndex].Value =XXX ；
                if (cp.flag)
                {
                    dgvNeed.Rows[e.RowIndex].Cells[e.ColumnIndex].Value = cp.selectedPart.Name;
                   ...
                }

            }


        }

------解决方案--------------------

参考:http://topic.csdn.net/u/20090412/15/eb6cde5b-e713-49c0-8a11-2e37ab74189b.html

感觉对DataGridViewComboBoxCell操作挺难的, 干脆你自己在DataGridView上添加Combox控件, 直接对Combox控件操作好了.

------解决方案--------------------
显然这里 用模板列  更OK！

SelectionChangeCommitted事件 里面 有重新对 combobox2 数据绑定？

------解决方案--------------------

        DataTable dtB;
       private void button2_Click(object sender, EventArgs e)
       {
           this.dataGridView1.CellValueChanged +=
               new System.Windows.Forms.DataGridViewCellEventHandler(this.dataGridView1_CellValueChanged_1);

           DataTable dtA = GetDataTable("A");
           this.Column1.DataSource = dtA.DefaultView;      // Column1, Column2, Column3分别对应DataGridView的三个列
           this.Column1.DisplayMember = "A表列1";

           dtB = GetDataTable("B");
           this.Column2.DataSource = dtB.DefaultView;
           this.Column2.DisplayMember = "B表列2";
       }
       private void dataGridView1_CellValueChanged_1(object sender, DataGridViewCellEventArgs e)
       {
           if (this.dataGridView1.CurrentRow == null || this.dataGridView1.CurrentCell.Value == null)
               return;

           switch (this.dataGridView1.CurrentCell.ColumnIndex)
           {
               case 0:
                   DataRow dr = dtB.Select("B表列1='" + this.dataGridView1.CurrentRow.Cells[0].Value.ToString() + "'")[0];

                   DataGridViewComboBoxCell dgc = (DataGridViewComboBoxCell)this.dataGridView1.CurrentRow.Cells[1];
                   dgc.Value = dr[1];

                   this.dataGridView1.CurrentRow.Cells[2].Value = dr[2];
                   break;
               case 1:
                   this.dataGridView1.CurrentRow.Cells[2].Value =
                       dtB.Select("B表列2='" + this.dataGridView1.CurrentRow.Cells[1].Value.ToString() + "'")[0][2];
                   break;
           }
       }
       private DataTable GetDataTable(string str)
       {
           DataTable dt = new DataTable(str);
           dt.Columns.Add(str + "表列1");
           dt.Columns.Add(str + "表列2");
           dt.Columns.Add(str + "表列3");

           for (int i = 0; i < 3; i++)
               dt.Rows.Add(string.Format("行{0}", i),
                   string.Format("{0}之行{1}", str, i),
                   string.Format("{0}之值{1}", str, i));
           return dt;