<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<!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></title>
<link href="dark.css" rel="stylesheet" type="text/css" id="stylesheet" />
</head>
<body>
<form id="form1" runat="server">
<div>
</div>
<asp:Button ID="Button1" runat="server" onclick="Button1_Click" Text="Button" />
<asp:Label ID="CaptionLabel" runat="server"></asp:Label>
<asp:TextBox ID="NumberTextbox" runat="server">(empty)</asp:TextBox>
<asp:Button ID="SquareButton" runat="server" Text="Square" style="background-color:Blue; color:White;" />
<asp:Label ID="ResultLabel" runat="server" Text="(empty)" CssClass="reverse"></asp:Label>
<p>
<asp:Label ID="Label1" runat="server" CssClass="footer1"
Text="Label Label Label Label LabelLabelLabel Label Label Label Label Label Label Label"></asp:Label>
</p>
<asp:RadioButton ID="radioDark" runat="server" AutoPostBack="True"
Checked="True" GroupName="grpSelectStylesheet"
oncheckedchanged="SwitchStylesheets" Text="Dark" />
<br />
<asp:RadioButton ID="radioLight" runat="server" AutoPostBack="True"
GroupName="grpSelectStylesheet" oncheckedchanged="SwitchStylesheets"
Text="Light" />
<asp:GridView ID="GridView1" runat="server">
</asp:GridView>
</form>
</body>
</html>
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void SwitchStylesheets(object sender, EventArgs e)
{
if (radioDark.Checked)
stylesheet.Href = "dark.css";
if (radioLight.Checked)
stylesheet.Href = "light.css";
}
protected void Button1_Click(object sender, EventArgs e)
{
int count=DateTime.Now.Second;
for (int i = 0; i < count; i++)
{//for
Label q = new Label();
q.ID = DateTime.Now.Second.ToString();
q.Text = DateTime.Now.Second.ToString();
string spacee = "<br />";
Label space = new Label();
space.Text = spacee;
form1.Controls.Add(q);
form1.Controls.Add(space);
}//for
}
}
单击该按钮时，它按预期工作，但页脚不会注册页面的扩展。
你的代码是完全错误的。即使autopostback设置为true，也无法为控件更改这样的样式表。 更新：这是你应该怎么做：
1-从页面中删除.css参考。 2-将此方法添加到您的页面：
private void UpdateStylesheet(string filepath)
{
HtmlLink newStyleSheet = new HtmlLink();
newStyleSheet.Href = filepath;
newStyleSheet.Attributes.Add("type", "text/css");
newStyleSheet.Attributes.Add("rel", "stylesheet");
Page.Header.Controls.Add(newStyleSheet);
}
3-将此行添加到page_load事件：
UpdateStylesheet("dark.css");
4-像这样处理SwitchStylesheets：
if (radioDark.Checked)
UpdateStylesheet("dark.css");
if (radioLight.Checked)
UpdateStylesheet("light.css");