页面代码如下：<asp:GridView ID="givClass"  Height="315px" Width="100%"  runat="server" AutoGenerateColumns="False" BorderStyle="Solid" DataKeyNames="claNumber"  OnRowDeleting="givClass_RowDeleting" OnRowEditing="givClass_RowEditing">
                <Columns>
                    <asp:TemplateField FooterText="班级编号" HeaderText="班级编号">
                        <EditItemTemplate>
                            <asp:TextBox ID="TextBox1" runat="server" Text='<%# Bind("claNumber") %>'></asp:TextBox>
                        </EditItemTemplate>
                        <ItemTemplate>
                            <asp:Label ID="Label1" runat="server" Text='<%# Bind("claNumber") %>'></asp:Label>
                        </ItemTemplate>
                    </asp:TemplateField>
                    <asp:BoundField DataField="claNumber" FooterText="班级名称" HeaderText="班级名称" />
                    <asp:BoundField DataField="claHeadTeacherName" FooterText="班主任姓名" HeaderText="班主任姓名" />
                    <asp:BoundField DataField="claProfessional" FooterText="所学专业" HeaderText="所学专业" />
                    <asp:BoundField DataField="claHeaTeaMobile" FooterText="班主任手机号" HeaderText="班主任手机号" />
                    <asp:BoundField DataField="claPeoAmount" FooterText="班级人数" HeaderText="班级人数" />
                    <asp:BoundField DataField="claMemo" FooterText="班级备注信息" HeaderText="班级备注信息" />
                    <asp:CommandField ButtonType="Button" HeaderText="编辑" ShowEditButton="True" />
                    <asp:CommandField ButtonType="Button" HeaderText="删除" ShowDeleteButton="True" />
                </Columns>
                <RowStyle Font-Size="12px" Height="21px" />
                <HeaderStyle Font-Size="9px" />
            </asp:GridView>
我想在触发RowEditing 事件时，将GrideView中的数据传到TextBox中，该如何做？