Response.Redirect()应该在以下情况下使用:

我们希望将请求重定向到我们服务器上的一些普通HTML页面或其他web服务器 我们不关心在每个请求上引起到服务器的额外往返 我们不需要保留原始请求中的查询字符串和表单变量 我们希望我们的用户能够看到新的重定向URL，他在他的浏览器重定向(并能够收藏它，如果它的必要)

Server.Transfer()应该在以下情况下使用:

我们希望将当前页面请求传输到同一服务器上的另一个.aspx页面 我们希望保留服务器资源并避免到服务器的不必要的往返 我们想保留查询字符串和表单变量(可选) 我们不需要在用户的Web浏览器中显示我们重定向请求的真实URL

简而言之:回应。重定向只是告诉浏览器访问另一个页面。服务器。Transfer有助于减少服务器请求，保持URL相同，并且通过一些错误处理，允许您传输查询字符串和表单变量。

我发现并同意以下观点:

Server.Transfer is similar in that it sends the user to another page with a statement such as Server.Transfer("WebForm2.aspx"). However, the statement has a number of distinct advantages and disadvantages. Firstly, transferring to another page using Server.Transfer conserves server resources. Instead of telling the browser to redirect, it simply changes the "focus" on the Web server and transfers the request. This means you don't get quite as many HTTP requests coming through, which therefore eases the pressure on your Web server and makes your applications run faster. But watch out: because the "transfer" process can work on only those sites running on the server; you can't use Server.Transfer to send the user to an external site. Only Response.Redirect can do that. Secondly, Server.Transfer maintains the original URL in the browser. This can really help streamline data entry techniques, although it may make for confusion when debugging. That's not all: The Server.Transfer method also has a second parameter—"preserveForm". If you set this to True, using a statement such as Server.Transfer("WebForm2.aspx", True), the existing query string and any form variables will still be available to the page you are transferring to. For example, if your WebForm1.aspx has a TextBox control called TextBox1 and you transferred to WebForm2.aspx with the preserveForm parameter set to True, you'd be able to retrieve the value of the original page TextBox control by referencing Request.Form("TextBox1").

Response.Redirect Response.Redirect() will send you to a new page, update the address bar and add it to the Browser History. On your browser you can click back. It redirects the request to some plain HTML pages on our server or to some other web server. It causes additional roundtrips to the server on each request. It doesn’t preserve Query String and Form Variables from the original request. It enables to see the new redirected URL where it is redirected in the browser (and be able to bookmark it if it’s necessary). Response. Redirect simply sends a message down to the (HTTP 302) browser.

Server.Transfer Server.Transfer() does not change the address bar, we cannot hit back.One should use Server.Transfer() when he/she doesn’t want the user to see where he is going. Sometime on a "loading" type page. It transfers current page request to another .aspx page on the same server. It preserves server resources and avoids the unnecessary roundtrips to the server. It preserves Query String and Form Variables (optionally). It doesn’t show the real URL where it redirects the request in the users Web Browser. Server.Transfer happens without the browser knowing anything, the browser request a page, but the server returns the content of another.

响应。重定向涉及一个额外的往返和更新地址栏。

服务器。传输不会导致地址栏更改，服务器会用来自另一个页面的内容响应请求

e.g.

响应。重定向:

在客户机上，浏览器请求一个页面http://InitiallyRequestedPage.aspx 在服务器上响应请求，302传递重定向地址http://AnotherPage.aspx。 在客户机上，浏览器向地址http://AnotherPage.aspx发出第二个请求。 在服务器上响应来自http://AnotherPage.aspx的内容

服务器。转让:

在客户机上，浏览器请求一个页面http://InitiallyRequestedPage.aspx 在服务器上。转至http://AnotherPage.aspx 在服务器上，对http://InitiallyRequestedPage.aspx的请求做出响应，从http://AnotherPage.aspx返回内容

响应。重定向

优点:- RESTful -它改变地址栏，地址可以用来记录请求之间的状态变化。

缺点:- 慢——在客户端和服务器之间有一个额外的往返。当客户端和服务器之间存在大量延迟时，这样做的代价可能会很高。

服务器。转移

优点:- 快。

缺点:- 状态丢失-如果您正在使用服务器。转移来改变应用程序的状态以响应回贴，如果页面随后被重新加载，该状态将丢失，因为地址栏将与第一次请求时相同。

响应。重定向的代价更大，因为它向服务器添加了额外的行程，以确定要去哪里。

服务器。传输是更有效的，但它可能会误导用户，因为Url没有物理改变。

根据我的经验，性能上的差异还没有大到可以使用后一种方法

更多关于Transfer()的细节，它实际上是Server.Execute() + Response.End()，它的源代码如下(来自Mono/.net 4.0):

public void Transfer (string path, bool preserveForm)
{
    this.Execute (path, null, preserveForm, true);
    this.context.Response.End ();
}

对于Execute()，它要运行的是给定路径的处理程序，参见

ASP.NET does not verify that the current user is authorized to view the resource delivered by the Execute method. Although the ASP.NET authorization and authentication logic runs before the original resource handler is called, ASP.NET directly calls the handler indicated by the Execute method and does not rerun authentication and authorization logic for the new resource. If your application's security policy requires clients to have appropriate authorization to access the resource, the application should force reauthorization or provide a custom access-control mechanism. You can force reauthorization by using the Redirect method instead of the Execute method. Redirect performs a client-side redirect in which the browser requests the new resource. Because this redirect is a new request entering the system, it is subjected to all the authentication and authorization logic of both Internet Information Services (IIS) and ASP.NET security policy. -from MSDN