模板的问题
模板
<%@ Master Language="C#" AutoEventWireup="true" CodeFile="MasterPage.master.cs" Inherits="MasterPage" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>无标题页</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<asp:contentplaceholder id="ContentPlaceHolder1" runat="server">
</asp:contentplaceholder>
</div>
</form>
</body>
</html>
页面
<%@ Page Language="C#" MasterPageFile="~/ASKPrice/MasterPage.master" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="ASKPrice_Default" Title="Untitled Page" %>
<asp:Content ID="Content1" ContentPlaceHolderID="contentplaceholder1" Runat="Server">
<asp:TextBox ID="product1_name" runat="server"></asp:TextBox>
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="提交询价" EnableTheming="False" PostBackUrl="~/ASKPrice/Default.aspx" />
</asp:Content>
cs文件
protected void Button1_Click(object sender, EventArgs e)
{
string s = ((TextBox)Page.Form.FindControl("product1_name")).Text;
}
报错:异常详细信息: System.NullReferenceException: 未将对象引用设置到对象的实例。
cs文件
protected void Button1_Click(object sender, EventArgs e)
{
string s = ((TextBox)this.FindControl("product1_name")).Text;
}
成功 什么原因 ?