把其中一列转化为模板列后，在aspx文件里修改。
<asp:TemplateColumn SortExpression="hint" HeaderText="学习提示">
<HeaderTemplate>
<FONT face="宋体">学习提示</FONT>
</HeaderTemplate>
<ItemTemplate>
<asp:textbox id=tbhint Font-Size="9pt" text='<%# databinder.eval(container.dataitem,"hint")%>' Runat="server">
</asp:textbox>
</ItemTemplate>
<EditItemTemplate>
<asp:dropdownlist id="edit_hint" BorderWidth="1px"  datasource='<%# datasource1%>' datatextfield="textfield" datavaluefield="valuefield" Runat="server" >
</asp:dropdownlist>
</EditItemTemplate>
</asp:TemplateColumn>

这个问题老外早想到了，看看这个吧！

How do I add a DropDownList to EditItemTemplate, using an Access database, and then some? 
 
By: Donny Mack
Level: Beginner
Posted Date: 7/24/2001
Tested with ASP.NET Beta 2 (v.1.0.2914.16)
 Click for Printable Version
 Click here to download sample code
 Member Rating: 3.50 (Rated by 2 members) 
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--------------------------------------------------------------------------------
In a recent artlicle we discussed how to populate a DropDownList box from within a DataGrid's Column while the DataGrid was in "edit mode". Well, this article builds off that example, and adds some new elements and features. First, instead of using the SQL we are going to use Access - specifically, the Northwind database. Second, when filling the DropDownList we aren't going to make a seperate call to the database to get the data - instead we are going to use a DataView and filter out the specific rows we need to populate each individual DropDownList. Third, we are going to save the changes back to Access once they have been edited.  
Listing 1.1 contains the code we are going to be working with for this example:  
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.OleDb" %>

<script language="c#" runat="server">

  OleDbDataAdapter OleDbDa;
  OleDbConnection SqlCon;
  DataView dvProducts;
  DataSet ds;

    protected void Page_Load(Object sender, EventArgs e){

      string path = Request.MapPath("nwind.Mdb");
      SqlCon = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;data source=" + path);

      if (! IsPostBack){

        BindGrid();

      }

    }

    protected void BindGrid(){

        OleDbDa = new OleDbDataAdapter("SELECT S.*, (SELECT COUNT(*) FROM Products AS P WHERE P.SupplierID = S.SupplierID) AS [ProductCount] FROM Suppliers AS S", SqlCon);
        ds = new DataSet();
        OleDbDa.Fill(ds, "Suppliers");
        OleDbDa.SelectCommand = new OleDbCommand("SELECT ProductName, ProductID, SupplierID FROM Products", SqlCon);
        OleDbDa.Fill(ds, "Products");
        dvProducts = ds.Tables["Products"].DefaultView;
        MyDataGrid.DataSource = ds.Tables["Suppliers"];
        Page.DataBind();

    }

    protected DataView GetProducts(int SupplierID){

        dvProducts.RowFilter = "SupplierID = " + SupplierID;
        return dvProducts;

    }

    protected void MyDataGrid_Edit(Object sender, DataGridCommandEventArgs e) {

        MyDataGrid.EditItemIndex = e.Item.ItemIndex;
        BindGrid();

    }

    protected void MyDataGrid_Cancel(Object sender, DataGridCommandEventArgs e) {

        MyDataGrid.EditItemIndex = -1;
        BindGrid();

    }

    protected void MyDataGrid_Update(Object sender, DataGridCommandEventArgs e) {

        string ChangeProductNameFrom = (string)((DropDownList)(e.Item.FindControl("edit_Product"))).SelectedItem.Text;
        string ChangeProductNameTo = (string)((TextBox)(e.Item.FindControl("NewProductName"))).Text;
        int ProductID = int.Parse((string)((DropDownList)(e.Item.FindControl("edit_Product"))).SelectedItem.Value);
        OleDbCommand odbcommand = new OleDbCommand("UPDATE Products SET ProductName = @ProductName WHERE ProductID = @ProductID", SqlCon);
        odbcommand.Parameters.Add(new OleDbParameter("@Productname", OleDbType.VarChar, 500));
        odbcommand.Parameters["@ProductName"].Value = ChangeProductNameTo;
        odbcommand.Parameters.Add(new OleDbParameter("@ProductID", OleDbType.Integer));
        odbcommand.Parameters["@ProductID"].Value = ProductID;

        if (ChangeProductNameTo.Length > 0) {

          try {

            SqlCon.Open();
            odbcommand.ExecuteNonQuery();
            SqlCon.Close();
            Message.Text = ChangeProductNameFrom + " <B>HAS BEEN CHANGED TO</B> " + ChangeProductNameTo;

          } catch (OleDbException OleDbEx) {

            Message.Text = "An Exception Has Occured: " + OleDbEx.Message.ToString();

          } finally {

            MyDataGrid.EditItemIndex = -1;
            BindGrid();

          }

        } else {

          Message.Text = "You must specify a new product name or hit cancel!";

        }

        }

</script>
<html>
<body>
  <form runat="server">
  <center>
    <asp:Label id="Message" MaintainState="false" ForeColor="#CC3300" Font-Size="11pt" runat="server"/><p>

    <ASP:DataGrid
      id="MyDataGrid"
      runat="server"
      Width="800"
      CellPadding=3
      CellSpacing="0"
      OnEditCommand="MyDataGrid_Edit"
      OnCancelCommand="MyDataGrid_Cancel"
      OnUpdateCommand="MyDataGrid_Update"
      DataKeyField="SupplierID"
      BorderColor="Tan"
      ShowFooter="false"
      Font-Name="Verdana"
      Font-Size="8pt"
      HeaderStyle-Font-Bold="True"
      HeaderStyle-BackColor="Maroon"
      AutoGenerateColumns="False"
      HeaderStyle-ForeColor="Tan" >

        <columns>

        <asp:EditCommandColumn
          EditText="Edit"
          CancelText="Cancel"
          UpdateText="Update"
          ItemStyle-VerticalAlign="top" />

        <asp:BoundColumn
          HeaderText="ID"
          ReadOnly="True"
          DataField="SupplierID"
          ItemStyle-Wrap="false"
          ItemStyle-VerticalAlign="top" />

        <asp:BoundColumn
          HeaderText="ID"
          ReadOnly="True"
          DataField="CompanyName"
          ItemStyle-Wrap="false"
          ItemStyle-VerticalAlign="top" />

        <asp:TemplateColumn HeaderText="Products" >

          <ItemTemplate>
            <%# DataBinder.Eval(Container.DataItem, "ProductCount") %> Products
          </ItemTemplate>

          <EditItemTemplate>

            <TABLE Width="100%" CellPadding="0" CellSpacing="0" Border="0">
              <TR>
                <TD Style="font-size:8" Width="20%">
                  <b>CHANGE -</b>
                </TD>
                <TD>
                  <asp:DropDownList
                    Runat="server"
                    Id="edit_Product"
                    DataSource='<%# GetProducts((int)DataBinder.Eval(Container.DataItem, "SupplierID")) %>'
                    DataTextField="ProductName"
                    DataValueField="ProductID"
                    Width="200" />
                </TD>
              </TR>
              <TR>
                <TD Style="font-size:8" Width="20%">
                  <b>TO - </b>
                </TD>
                <TD>
                  <asp:TextBox
                    id="NewProductName"
                    runat="Server"
                    Width="200" />
                </TD>
              </TR>
            </TABLE>

          </EditItemTemplate>

          </asp:TemplateColumn>

        </columns>

      </asp:DataGrid>
  </center>
</form>
</body>
</html>
 

看我的：先定义用户控件 usercontrol.ascx(使用xml和使用数据库一样道理)
<%@ import namespace="system.data"%>
<script language="vb" runat=server>
   Dim xmlds As DataSet=new dataset()
   Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) 
        xmlds.ReadXml(Server.MapPath("new_class.xml"))
        drop.DataSource=xmlds
        drop.DataBind()
    End Sub
   
</script>
 <html>
  <body>
    <select id="drop"  DataTextField="classname" runat=server/>
  </body>
</HTML>
然后在另一个aspx文件调用：
<%@ register tagprefix="MyControl" tagname="dropdown" src="usercontrol.ascx"%>
......
datagrid中:
 <asp:TemplateColumn HeaderText="header">
    <ItemTemplate><%#container.dataitem("dataname")%></ItemTemplate>
    <EditItemTemplate>
    <MyControl:dropdown id=dropdown1 runat="server"></MyControl:dropdown>
    </EditItemTemplate>
    </asp:TemplateColumn>
   

经典！鼓掌！

我照前两种方法作，结果在编辑状态下，dropdownlist中的每个item的值都是空字符串，怎么回事啊？