一般情况下，Response.Redirect 方法是在服务器端进行转向，因此，除非使用 Response.Write("<script>window.location=\'http://dotnet.aspx.cc\';</script>") 方法外，是不能在新窗口打开所指定的 URL 地址的。但是，如果仔细分析一下，如果设置 form 元素的 target 属性，还是有办法打开新窗口的。下面就是可以采用的两种方法。
方法一：在服务器端设置 target 属性，这个方法也非常适用于客户端不支持脚本的情况。代码如下：
<%@ Page Language="C#" AutoEventWireup="true" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
form1.Target = "_blank";
}
protected void Button1_Click(object sender, EventArgs e)
{
Response.Redirect("http://dotnet.aspx.cc");
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title></title>
</head>
<body id="b" runat="server">
<form id="form1" runat="server">
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="打开新窗口或者新 Tab " />
</form>
</body>
</html>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
form1.Target = "_blank";
}
protected void Button1_Click(object sender, EventArgs e)
{
Response.Redirect("http://dotnet.aspx.cc");
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title></title>
</head>
<body id="b" runat="server">
<form id="form1" runat="server">
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="打开新窗口或者新 Tab " />
</form>
</body>
</html>
办法二：采用客户端脚本的方法设置 target 属性。代码如下：
<%@ Page Language="C#" AutoEventWireup="true" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
Button1.Attributes.Add("onclick", "this.form.target=\'_newName\'");
}
protected void Button1_Click(object sender, EventArgs e)
{
Response.Redirect("http://dotnet.aspx.cc");
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title></title>
</head>
<body id="b" runat="server">
<form id="form1" runat="server">
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="打开新窗口或者新 Tab " />
</form>
</body>
</html>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
Button1.Attributes.Add("onclick", "this.form.target=\'_newName\'");
}
protected void Button1_Click(object sender, EventArgs e)
{
Response.Redirect("http://dotnet.aspx.cc");
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title></title>
</head>
<body id="b" runat="server">
<form id="form1" runat="server">
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="打开新窗口或者新 Tab " />
</form>
</body>
</html>
上面两种方法中的 target 属性可以采用任何合法的名称，但要注意，如果相同名称的窗口已经打开，则新窗口会在已经存在名称的窗口里打开。
更新：如果需要设置弹出窗口的宽度和高度，可以修改为下面的方法：
<%@ Page Language="C#" AutoEventWireup="true" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
string WindowName = "win" + System.DateTime.Now.Ticks.ToString();
Page.RegisterOnSubmitStatement("js", "window.open(\'\',\'" + WindowName + "\',\'width=600,height=200\')");
form1.Target = WindowName;
}
protected void Button1_Click(object sender, EventArgs e)
{
Response.Redirect("http://dotnet.aspx.cc");
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title></title>
</head>
<body id="b" runat="server">
<form id="form1" runat="server">
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="打开新窗口或者新 Tab " />
</form>
</body>
</html>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
protected void Page_Load(object sender, EventArgs e)
{
string WindowName = "win" + System.DateTime.Now.Ticks.ToString();
Page.RegisterOnSubmitStatement("js", "window.open(\'\',\'" + WindowName + "\',\'width=600,height=200\')");
form1.Target = WindowName;
}
protected void Button1_Click(object sender, EventArgs e)
{
Response.Redirect("http://dotnet.aspx.cc");
}
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
<title></title>
</head>
<body id="b" runat="server">
<form id="form1" runat="server">
<asp:Button ID="Button1" runat="server" OnClick="Button1_Click" Text="打开新窗口或者新 Tab " />
</form>
</body>
</html>
另外一种弹出的方法可以参见老外的文章：
http://weblogs.asp.net/infinitiesloop/archive/2007/09/25/response-redirect-into-a-new-window-with-extension-methods.aspx