Response.Rederect在默认情况下是在本页跳转，所以除了在js中用window.open 或是给A标签添加target属性之外，在后台似乎不能来打开新的页面，其实不然，通过设置form的target属性同样可以让 Response.Rederect所指向的url在新的窗口打开。下面用三种方法来实现。
1 .给form指定target属性，那么本页面中所有的Response.Rederect都将在新的窗口中打开。代码如下：
protected void Page_Load( object sender, EventArgs e)
{
form1.Target = "_blank" ;
}
或
< form id ="form2" runat ="server" target ="_blank">
2 .用脚本针对某个控件来指定form的target，代码如下：
html代码：
<% @ Page Language ="C#" AutoEventWireup ="true" CodeBehind ="Default.aspx.cs"
Inherits ="ResponseRedirectDemo._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 id ="Head1" runat ="server">
< title > ResponseRedirectDemo </ title >
</ head >
< body >
< form id ="form2" runat ="server" target ="_blank">
< div >
< asp : Button ID ="Button1" runat ="server" OnClick ="Button1_Click"
Text ="OpenNewWindow"/>
< asp : Button ID ="Button2" runat ="server" OnClick ="Button2_Click"
Text ="OpenOldWindow" />
</ div >
</ form >
</ body >
</ html >
C#代码：
namespace ResponseRedirectDemo
{
public partial class _Default : System.Web.UI. Page
{
protected void Page_Load( object sender, EventArgs e)
{
Button1.Attributes.Add( "onclick" , "this.form.target='_blank'" );
Button2.Attributes.Add( "onclick" , "this.form.target=''" );
}
protected void Button1_Click( object sender, EventArgs e)
{
Response.Redirect( "http://oec2003.cnblogs.com" );
}
protected void Button2_Click( object sender, EventArgs e)
{
Response.Redirect( "http://oec2003.cnblogs.com" );
}
}
}
上面的代码中点击button1在新窗口打开，点击button2在本页打开。
3 .除了设置form的target属性，要在新的窗口打开页面就只能用open，可以写个通用的方法来实现，如下：
public class RedirectHelper
{
public static void Redirect( string url,
string target, string windowFeatures)
{
HttpContext context = HttpContext .Current;
if (( String .IsNullOrEmpty(target) ||
target.Equals( "_self" , StringComparison .OrdinalIgnoreCase)) &&
String .IsNullOrEmpty(windowFeatures))
{
context.Response.Redirect(url);
}
else
{
Page page = ( Page )context.Handler;
if (page == null )
{
throw new
InvalidOperationException ( "Cannot redirect to new window." );
}
url = page.ResolveClientUrl(url);
string script;
if (! String .IsNullOrEmpty(windowFeatures))
{
script = @"window.open(""{0}"", ""{1}"", ""{2}"");" ;
}
else
{
script = @"window.open(""{0}"", ""{1}"");" ;
}
script = String .Format(script, url, target, windowFeatures);
page.ClientScript.RegisterStartupScript(page.GetType(),
"Redirect" , script, true );
}
}
}
这样就可以在程序中使用RedirectHelper.Redirect("oec2003.aspx", "_blank", ""); 第三个参数为open窗口的一些属性 。但这样好像还不是很方便，在.net3.5中提供了扩展方法的特性，在这里也可以借用一下，将上面的静态方法实现为Response.Redirect 的一个重载。具体代码如下：
public static class RedirectHelper
{
public static void Redirect( this HttpResponse response,
string url, string target, string windowFeatures)
{
if (( String .IsNullOrEmpty(target) ||
target.Equals( "_self" , StringComparison .OrdinalIgnoreCase)) &&
String .IsNullOrEmpty(windowFeatures))
{
response.Redirect(url);
}
else
{
Page page = ( Page ) HttpContext .Current.Handler; if (page == null )
{
throw new
InvalidOperationException ( "Cannot redirect to new window ." );
}
url = page.ResolveClientUrl(url);
string script;
if (! String .IsNullOrEmpty(windowFeatures))
{
script = @"window.open(""{0}"", ""{1}"", ""{2}"");" ;
}
else
{
script = @"window.open(""{0}"", ""{1}"");" ;
}
script = String .Format(script, url, target, windowFeatures);
ScriptManager .RegisterStartupScript(page,
typeof ( Page ), "Redirect" , script, true );
}
}
}
将该类添加到项目中后，在程序中输入Response.Redirect会发现该方法有三个重载了，这样再结合前面的form的target 就非常方便了。
出处：http://www.cnblogs.com/oec2003/archive/2009/01/07/1371373.html