我想在.CS当中简单地引用.aspx中的一个TextBox控件，但是就是死活不成功。
下面是源码：
.cs:
protected void chengji_Click(object sender, EventArgs e)
{
for (int i = 0; i < this.gv_chengji.Rows.Count; i++)
{
TextBox box = this.gv_chengji.Rows[i].FindControl("TextBox2") as TextBox;
string text = this.gv_chengji.Rows[i].Cells[1].Text;
this.update(text, box.Text);
}
TextBox TextBox3 = this.FindControl("TextBox3") as TextBox;
TextBox TextBox4 = this.FindControl("TextBox4") as TextBox;
TextBox TextBox5 = this.FindControl("TextBox5") as TextBox;
string year = TextBox3.Text.ToString();
string month = TextBox4.Text.ToString();
string day = TextBox5.Text.ToString();
}
.aspx:
<%@ page title="" language="C#" masterpagefile="~/MasterPage/MasterPage.master" autoeventwireup="true" inherits="ResultManage_Resultin, App_Web_resultin.aspx.ce51174c" enableeventvalidation="false" %>
<asp:Content ID="Content1" ContentPlaceHolderID="head" runat="Server">
</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" runat="Server">
<table width="800">
<tr>
<td width="80" height="30">队别：</td>
<td width="80">
<asp:DropDownList ID="DropDownList2" runat="server" AutoPostBack="True"
onselectedindexchanged="DropDownList2_SelectedIndexChanged">
</asp:DropDownList>
</td>
<td width="80">
<asp:Label ID="Label2" runat="server" Text="比赛项目:"></asp:Label>
</td>
<td width="80" align="center" colspan="2">
<asp:DropDownList ID="DropDownList1" runat="server" OnSelectedIndexChanged="DropDownList1_SelectedIndexChanged" AutoPostBack="True"></asp:DropDownList>
</td>
<td width="80" align="center">
<asp:Button ID="chengji" runat="server" OnClick="chengji_Click" Text="保存更改" Width="66px" />
</td>
<td width="80" colspan="2">
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click"
Text="导出成绩表(.xls)" Style="margin-left: 0px" Width="122px" />
</td>
<td width="80" colspan="2">
<asp:Button ID="Button12" runat="server" OnClick="Button12_Click"
Text="生成成绩表(.doc)" Width="117px" />
</td>
<td>
<asp:Button ID="Button13" runat="server" OnClick="Button13_Click"
Text="导出成绩表(.doc)" Width="117px" />
</td>
</tr>
<table>
<tr height="20">
<td >录入时间：
</td>
<td >
<asp:TextBox ID="TextBox3" runat="server" Width="45px" ></asp:TextBox>
<asp:Label ID="Label3" runat="server" Text="年" Width="15px"></asp:Label>
</td>
<td >
<asp:TextBox ID="TextBox4" runat="server" Width="45px" ></asp:TextBox>
<asp:Label ID="Label4" runat="server" Text="月" Width="15px"></asp:Label>
</td>
<td >
<asp:TextBox ID="TextBox5" runat="server" Width="45px" ></asp:TextBox>
<asp:Label ID="Label5" runat="server" Text="日" Width="15px"></asp:Label>
</td>
</tr>
<table>
</tr>
<%--<tr><td colspan ="10" height="20"> <iframe src="../ResultManage/ProgressBar.htm" name="RightFrame" frameborder="no" scrolling="no" height="20" style="width: 383px"></iframe></td></tr>
<tr>--%>
<tr>
<td colspan="12" align="center">
<asp:GridView ID="gv_chengji" runat="server" AutoGenerateColumns="False" BackColor="White"
BorderColor="#336666" BorderStyle="Double" BorderWidth="3px"
CellPadding="4" GridLines="Horizontal" AllowPaging="True" OnPageIndexChanging="gv_chengji_PageIndexChanging1" OnRowCommand="gv_chengji_RowCommand">
<Columns>
<asp:TemplateField HeaderText="序号">
<ItemTemplate>
<asp:Literal ID="Literal1" runat="server" Text="<%# Container.DataItemIndex+1 %>"></asp:Literal>
</ItemTemplate>
</asp:TemplateField>
<%--<asp:ImageField DataImageUrlField="score" HeaderText="照片"
NullImageUrl="~/Image/red/1402003.jpg">
<ControlStyle Height="80px" Width="60px" />
</asp:ImageField>--%>
<asp:BoundField DataField="ID" HeaderText="学号" ReadOnly="True"
SortExpression="学号" />
<asp:BoundField DataField="name" HeaderText="姓名" ReadOnly="True"
SortExpression="姓名" />
<asp:BoundField DataField="sex" HeaderText="性别" ReadOnly="True"
SortExpression="性别" />
<asp:BoundField DataField="level" HeaderText="层次" ReadOnly="True"
SortExpression="层次" />
<asp:BoundField DataField="Big_unit" HeaderText="大单位" ReadOnly="True"
SortExpression="大单位" />
<asp:BoundField DataField="unit" HeaderText="小单位" ReadOnly="True"
SortExpression="小单位" />
<asp:BoundField DataField="year" HeaderText="入学年份" ReadOnly="True"
SortExpression="入学年份" />
<%--<asp:BoundField DataField="event_num" HeaderText="竞赛编号" ReadOnly="True"
SortExpression="竞赛编号" />--%>
<asp:BoundField DataField="compevent" HeaderText="竞赛名称" ReadOnly="True"
SortExpression="竞赛名称" />
<asp:TemplateField HeaderText="比赛成绩" SortExpression="比赛成绩">
<EditItemTemplate>
<asp:TextBox ID="TextBox1" runat="server" Text='<%# Bind("score") %>'></asp:TextBox>
</EditItemTemplate>
<ItemTemplate>
<asp:TextBox ID="TextBox2" runat="server"
Text='<%# DataBinder.Eval(Container.DataItem,"score") %>'></asp:TextBox>
</ItemTemplate>
</asp:TemplateField>
</Columns>
<PagerTemplate>
<br/>
<asp:Label ID="lblPage1" runat="Server" Text='<%# "第" +( ((GridView)Container.NamingContainer).PageIndex +1 ) +"页/共"+ (((GridView)Container.NamingContainer).PageCount) +"页" %>'></asp:Label>
<asp:LinkButton ID="lbnFirst1" runat="Server" Text="首页" Enabled='<%# ((GridView)Container.NamingContainer).PageIndex != 0 %>' CommandName="Page" CommandArgument="First"></asp:LinkButton>
<asp:LinkButton ID="lbnPrev1" runat="server" Text="上一页" Enabled='<%# ((GridView)Container.NamingContainer).PageIndex != 0 %>' CommandName="Page" CommandArgument="Prev"></asp:LinkButton>
<asp:LinkButton ID="lbnNext1" runat="Server" Text="下一页" Enabled='<%# ((GridView)Container.NamingContainer).PageIndex != (((GridView)Container.NamingContainer).PageCount - 1) %>' CommandName="Page" CommandArgument="Next"></asp:LinkButton>
<asp:LinkButton ID="lbnLast1" runat="Server" Text="尾页" Enabled='<%# ((GridView)Container.NamingContainer).PageIndex != (((GridView)Container.NamingContainer).PageCount - 1) %>' CommandName="Page" CommandArgument="Last"></asp:LinkButton>
到第<asp:TextBox runat="server" ID="inPageNum1" Width="10mm"></asp:TextBox>页
<asp:Button ID="Button11" CommandName="go" Text="转到" runat="server" />
<br />
</PagerTemplate>
<FooterStyle BackColor="White" ForeColor="#333333" />
<HeaderStyle BackColor="#336666" Font-Bold="True" ForeColor="White" />
<PagerStyle BackColor="#336666" ForeColor="White" HorizontalAlign="Center" />
<RowStyle BackColor="White" ForeColor="#333333" />
<SelectedRowStyle BackColor="#339966" Font-Bold="True" ForeColor="White" />
<SortedAscendingCellStyle BackColor="#F7F7F7" />
<SortedAscendingHeaderStyle BackColor="#487575" />
<SortedDescendingCellStyle BackColor="#E5E5E5" />
<SortedDescendingHeaderStyle BackColor="#275353" />
</asp:GridView>
</td>
</tr>
</table>
</asp:Content>
已经调试过了，在chengji_click函数中，三条定义string的语句老是报错“未将对象引用到实例”，到底是为什么啊？？？大神救命啊！！！
