Url rewrite详细分析
from:http://www.cnblogs.com/oop/archive/2005/08/09/210929.html
.Text(博客园)Url rewrite详细分析
在写这篇随笔之前，其实网上早已有高手分析了.text的urlrewrite的实现（点击
这里查看全文），问题是作为一个初学者的我，看了以后，感觉没有切中要害。所以，产生了写这篇dd的冲动。
从头说起，.text是通过httpModules和httpHandlers来实现urlrewrite的，看看web.config中的配置
看看第11行，配置了 Dottext.Common.UrlManager.UrlReWriteModule这个httpModule，很显然，从名字来看，它就是实现urlrewrite功能的httpmodule，去看看它的源代码
代码有点长，不过没关系，结构还是很清晰的。用户发出的url请求，在context_BeginRequest中进行了第一次过滤，这个函数把url做了一下归整，判断来自用户的请求是 应用程序根目录下的.aspx文件，如果是则不进行urlrewrite（由UrlHelper.SetEnableUrlReWriting这个函数进行设置）。什么？看不懂regexPath = new Regex( @" ^/?(\w|-|_)＋\.aspx$ " ,…… ); 这句话？建议你去看一下正则表达式，这里的意思是指，需要匹配的字符串所对应的文件是否在根目录下，举例来说，
/contact.aspx
default.aspx
匹配，而
/oop80/default.aspx
则不匹配，
总而言之，context_BeginRequest函数把对根目录下.aspx文件的请求，以及webservice，设置成不需要进行urlrewrite，其余的，则需要进行下一步的处理，在什么地方处理呢，我们来看看web.config中的配置，第8行，很清晰的告诉我们，在Dottext.Common.UrlManager.UrlReWriteHandlerFactory中，会对用户的请求做进一步分析和处理。 来看看源代码
代码很长，但是它是实现urlrewrite的关键，我们来分析分析看。
UrlReWriteHandlerFactory实现了IHttpHandlerFactory接口，而IHttpHandlerFactory最关键的地方在于GetHandler这个函数接口，所以我们从GetHandler函数入手。
首先是 HttpHandler [] items = GetHttpHandlers(context)； 通过查看GetHttpHandlers的定义，可以得知返回的其实是HandlerConfiguration中一个叫HttpHandlers的属性，它的值，是通过这么一句话来进行初始化的，return ((HandlerConfiguration)ConfigurationSettings.GetConfig("HandlerConfiguration")); 想必大家现在都明白了，HandlerConfiguration对象是通过将web.config中<HandlerConfiguration>节进行反序列化获得的，关于ConfigurationSettings.GetConfig的使用，网上已经有很多了，在这里就不重复劳动了。看看web.config中的HandlerConfiguration节
其实在visual studio.net中看这段代码会更加清楚一点，这里的每一个pattern其实都会建立对应的Regex ，来对用户请求的url进行匹配，下面的代码会很详细说明这一点，我们往下看。
接下来是一个循环，循环中执行这么一句话
if (items[i].IsMatch(Dottext.Framework.Util.Globals.RemoveAppFromPath(context.Request.Path,context.Request.ApplicationPath))) {...}
它把web.config中每一个httphandler来匹配用户的请求，IsMatch函数中会根据pattern建立相应的Regex，并调用Regex.IsMatch函数，如果请求匹配该pattern，则调用对应的模块来进行处理。很显然，这里是实现urlrewrite的关键之处，比如，请求的是这么一个url
http://oop80.cnblogs.com/archive/2005/08/09/210550.html
那么，他就会匹配这一个handler
<HttpHandler pattern="/archive/\d{4}/\d{2}/\d{2}/\d+\.(aspx|htm)$" controls="viewpost.ascx,Comments.ascx,AnonymousPostComment.ascx,LoginPostComment.ascx" />
那么，程序就会调用 viewpost.ascx,Comments.ascx,AnonymousPostComment.ascx,LoginPostComment.ascx 来处理用户的请求，
又如，请求这么一个url
http://oop80.cnblogs.com/category/23435.aspx
匹配
<HttpHandler pattern="/(?:category|stories)/(\w|\s)+\.aspx$" controls="CategoryEntryList.ascx" />
最后程序是一个switch语句，根据handlertype的不同进行各种处理，具体就不在解释了，因为……这一段我自己也没有进行更深入一步的研究，里面还有一些细节，如SetControls的控件在什么地方载入，GetCompiledPageInstance函数的具体用法等等。不过，这些东西终归和urlrewrite没多大关系了，不在我们讨论的范围之内。
请大家多多指教，谢谢
从头说起，.text是通过httpModules和httpHandlers来实现urlrewrite的，看看web.config中的配置
1
<
httpHandlers
>
2
<!--
Can not see to load asmx like .aspx, since we will grap all requests later, make sure these are processed by their default factory
-->
3
<
add
verb
="*"
path
="*.asmx"
type
="System.Web.Services.Protocols.WebServiceHandlerFactory, System.Web.Services, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"
4 validate
="false"
/>
5
<!--
Since we are grabbing all requests after this, make sure Error.aspx does not rely on .Text
-->
6
<
add
verb
="*"
path
="Error.aspx"
type
="System.Web.UI.PageHandlerFactory"
/>
7
<!--
This will process any ext mapped to aspnet_isapi.dll
-->
8
<
add
verb
="*"
path
="*"
type
="Dottext.Common.UrlManager.UrlReWriteHandlerFactory,Dottext.Common"
/>
9
</
httpHandlers
>
10
<
httpModules
>
11
<
add
name
="UrlReWriteModule"
type
="Dottext.Common.UrlManager.UrlReWriteModule, Dottext.Common"
/>
12
<
add
name
="EventHttpModule"
type
="Dottext.Framework.ScheduledEvents.EventHttpModule, Dottext.Framework"
/>
13
<!--
<add name="MsftBlogsHttpModule" type= "AspNetWeb.MsftBlogsHttpModule, MsftBlogsHttpModule" />
-->
14
</
httpModules
>
15
<
httpHandlers
>
2
<!--
Can not see to load asmx like .aspx, since we will grap all requests later, make sure these are processed by their default factory
-->
3
<
add
verb
="*"
path
="*.asmx"
type
="System.Web.Services.Protocols.WebServiceHandlerFactory, System.Web.Services, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"
4
validate
="false"
/>
5
<!--
Since we are grabbing all requests after this, make sure Error.aspx does not rely on .Text
-->
6
<
add
verb
="*"
path
="Error.aspx"
type
="System.Web.UI.PageHandlerFactory"
/>
7
<!--
This will process any ext mapped to aspnet_isapi.dll
-->
8
<
add
verb
="*"
path
="*"
type
="Dottext.Common.UrlManager.UrlReWriteHandlerFactory,Dottext.Common"
/>
9
</
httpHandlers
>
10
<
httpModules
>
11
<
add
name
="UrlReWriteModule"
type
="Dottext.Common.UrlManager.UrlReWriteModule, Dottext.Common"
/>
12
<
add
name
="EventHttpModule"
type
="Dottext.Framework.ScheduledEvents.EventHttpModule, Dottext.Framework"
/>
13
<!--
<add name="MsftBlogsHttpModule" type= "AspNetWeb.MsftBlogsHttpModule, MsftBlogsHttpModule" />
-->
14
</
httpModules
>
15
看看第11行，配置了 Dottext.Common.UrlManager.UrlReWriteModule这个httpModule，很显然，从名字来看，它就是实现urlrewrite功能的httpmodule，去看看它的源代码
1
static
UrlReWriteModule()
2
{
3
regexPath = new Regex(@"^/?(\w|-|_)+\.aspx$",RegexOptions.IgnoreCase|RegexOptions.Compiled);
4 regexApplication = new Regex(HttpContext.Current.Request.ApplicationPath,RegexOptions.IgnoreCase|RegexOptions.Compiled);
5
}
6
7
private
void
context_BeginRequest(
object
sender, EventArgs e)
8
{
9 if(ConfigProvider.Instance().IsAggregateSite)
10
{
11 HttpContext context = ((HttpApplication)sender).Context;
12
13 string path = context.Request.Path.ToLower();
14 int iExtraStuff = path.IndexOf(".aspx");
15 if(iExtraStuff > -1 || path.IndexOf(".") == -1)
16 {
17 if(iExtraStuff > -1)
18 {
19 path = path.Remove(iExtraStuff+5,path.Length - (iExtraStuff+5));
20
}
21
22 path = regexApplication.Replace(path,string.Empty,1,0);
23
24 if(path == "" || path == "/" || regexPath.IsMatch(path))
25 {
26 UrlHelper.SetEnableUrlReWriting(context,false);
27 }
28
29 }
30 else if(context.Request.Path.ToLower().IndexOf("services") > 0 && context.Request.Path.ToLower().IndexOf(".asmx") > 0 )
31 {
32 if(AlllowService(context))
33 {
34 if(context.Request.RequestType!="POST")
35 {
36 string regexstr=@"/\w+/services/";
37 string url=Regex.Replace(context.Request.RawUrl,regexstr,"/services/",RegexOptions.IgnoreCase);
38 context.RewritePath(url);
39 }
40 //string fileName =context.Request; //System.IO.Path.GetFileName(context.Request.Path);
41 //context.RewritePath("~/Services/" + fileName);
42 }
43 else
44 {
45 context.Response.Clear();
46 context.Response.End();
47 }
48 }
49
50 }
51 }
52
static
UrlReWriteModule() 2
{ 
3
regexPath = new Regex(@"^/?(\w|-|_)+\.aspx$",RegexOptions.IgnoreCase|RegexOptions.Compiled); 4
regexApplication = new Regex(HttpContext.Current.Request.ApplicationPath,RegexOptions.IgnoreCase|RegexOptions.Compiled); 5
}
6
7
private
void
context_BeginRequest(
object
sender, EventArgs e) 8
{ 9
if(ConfigProvider.Instance().IsAggregateSite) 10
{ 
11
HttpContext context = ((HttpApplication)sender).Context; 12
13
string path = context.Request.Path.ToLower(); 14
int iExtraStuff = path.IndexOf(".aspx"); 15
if(iExtraStuff > -1 || path.IndexOf(".") == -1) 16
{ 17
if(iExtraStuff > -1) 18
{ 19
path = path.Remove(iExtraStuff+5,path.Length - (iExtraStuff+5)); 20
} 21
22
path = regexApplication.Replace(path,string.Empty,1,0); 23
24
if(path == "" || path == "/" || regexPath.IsMatch(path)) 25
{ 26
UrlHelper.SetEnableUrlReWriting(context,false); 27
} 28
29
} 30
else if(context.Request.Path.ToLower().IndexOf("services") > 0 && context.Request.Path.ToLower().IndexOf(".asmx") > 0 ) 31
{ 32
if(AlllowService(context)) 33
{ 34
if(context.Request.RequestType!="POST") 35
{ 36
string regexstr=@"/\w+/services/"; 37
string url=Regex.Replace(context.Request.RawUrl,regexstr,"/services/",RegexOptions.IgnoreCase); 38
context.RewritePath(url); 39
} 40
//string fileName =context.Request; //System.IO.Path.GetFileName(context.Request.Path); 41
//context.RewritePath("~/Services/" + fileName); 42
} 43
else 44
{ 45
context.Response.Clear(); 46
context.Response.End(); 47
} 48
} 49
50
} 51
}
52
代码有点长，不过没关系，结构还是很清晰的。用户发出的url请求，在context_BeginRequest中进行了第一次过滤，这个函数把url做了一下归整，判断来自用户的请求是 应用程序根目录下的.aspx文件，如果是则不进行urlrewrite（由UrlHelper.SetEnableUrlReWriting这个函数进行设置）。什么？看不懂regexPath = new Regex( @" ^/?(\w|-|_)＋\.aspx$ " ,…… ); 这句话？建议你去看一下正则表达式，这里的意思是指，需要匹配的字符串所对应的文件是否在根目录下，举例来说，
/contact.aspx
default.aspx
匹配，而
/oop80/default.aspx
则不匹配，
总而言之，context_BeginRequest函数把对根目录下.aspx文件的请求，以及webservice，设置成不需要进行urlrewrite，其余的，则需要进行下一步的处理，在什么地方处理呢，我们来看看web.config中的配置，第8行，很清晰的告诉我们，在Dottext.Common.UrlManager.UrlReWriteHandlerFactory中，会对用户的请求做进一步分析和处理。 来看看源代码
1
public
class
UrlReWriteHandlerFactory: IHttpHandlerFactory
2
{
3 public UrlReWriteHandlerFactory(){} //Nothing to do in the cnstr
4
5 protected virtual HttpHandler[] GetHttpHandlers(HttpContext context)
6 {
7 return HandlerConfiguration.Instance().HttpHandlers;
8 }
9
10 /// <summary>
11 /// Implementation of IHttpHandlerFactory. By default, it will load an array of HttpHanlder (Dottext.UrlManager.HttpHandler) from
12 /// the blog.config. This can be changed, by overrideing the GetHttpHandlers(HttpContext context) method.
13 /// </summary>
14 /// <param name="context">Current HttpContext</param>
15 /// <param name="requestType">Request Type (Passed along to other IHttpHandlerFactory's)</param>
16 /// <param name="url">The current requested url. (Passed along to other IHttpHandlerFactory's)</param>
17 /// <param name="path">The physical path of the current request. Is not gaurenteed to exist (Passed along to other IHttpHandlerFactory's)</param>
18 /// <returns>
19 /// Returns an Instance of IHttpHandler either by loading an instance of IHttpHandler or by returning an other
20 /// IHttpHandlerFactory.GetHanlder(HttpContext context, string requestType, string url, string path) method
21 /// </returns>
22 public virtual IHttpHandler GetHandler(HttpContext context, string requestType, string url, string path)
23 {
24 //Get the Handlers to process. By defualt, we grab them from the blog.config
25 //Dottext.Framework.Logger.LogManager.Log("url",context.Request.Path);
26 HttpHandler[] items = GetHttpHandlers(context);
27 //Dottext.Framework.Logger.LogManager.Log("path",Dottext.Framework.Util.Globals.RemoveAppFromPath(context.Request.Path,context.Request.ApplicationPath));
28 //Do we have any?
29 if(items != null)
30 {
31 int count = items.Length;
32
33 for(int i = 0; i<count; i++)
34 {
35 //We should use our own cached Regex. This should limit the number of Regex's created
36 //and allows us to take advantage of RegexOptons.Compiled
37
38 if(items[i].IsMatch(Dottext.Framework.Util.Globals.RemoveAppFromPath(context.Request.Path,context.Request.ApplicationPath)))
39 {
40 //throw new Exception();
41 switch(items[i].HandlerType)
42 {
43 case HandlerType.Page://默认是Page
44
45 return ProccessHandlerTypePage(items[i],context,requestType,url);
46 case HandlerType.Direct:
47 HandlerConfiguration.SetControls(context,items[i].BlogControls);
48 return (IHttpHandler)items[i].Instance();
49 case HandlerType.Factory:
50 //Pass a long the request to a custom IHttpHandlerFactory
51 return ((IHttpHandlerFactory)items[i].Instance()).GetHandler(context,requestType,url,path);
52 default:
53 throw new Exception("Invalid HandlerType: Unknown");
54 }
55 }
56 }
57 }
58 //If we do not find the page, just let ASP.NET take over
59 return PageHandlerFactory.GetHandler(context,requestType,url, path);
60 }
61
62
63 private IHttpHandler ProccessHandlerTypePage(HttpHandler item, HttpContext context, string requestType, string url)
64 {
65 string pagepath = item.FullPageLocation;
66 if(pagepath == null)
67 {
68 pagepath = HandlerConfiguration.Instance().FullPageLocation;
69 }
70 HandlerConfiguration.SetControls(context,item.BlogControls);
71 IHttpHandler myhandler=PageParser.GetCompiledPageInstance(url,pagepath,context);
72 return myhandler;
73 }
74
75
76 public virtual void ReleaseHandler(IHttpHandler handler)
77 {
78
79 }
80 }
81
public
class
UrlReWriteHandlerFactory: IHttpHandlerFactory 2
{ 3
public UrlReWriteHandlerFactory(){} //Nothing to do in the cnstr 4
5
protected virtual HttpHandler[] GetHttpHandlers(HttpContext context) 6
{ 7
return HandlerConfiguration.Instance().HttpHandlers; 8
} 9
10
/// <summary> 11
/// Implementation of IHttpHandlerFactory. By default, it will load an array of HttpHanlder (Dottext.UrlManager.HttpHandler) from 12
/// the blog.config. This can be changed, by overrideing the GetHttpHandlers(HttpContext context) method. 13
/// </summary> 14
/// <param name="context">Current HttpContext</param> 15
/// <param name="requestType">Request Type (Passed along to other IHttpHandlerFactory's)</param> 16
/// <param name="url">The current requested url. (Passed along to other IHttpHandlerFactory's)</param> 17
/// <param name="path">The physical path of the current request. Is not gaurenteed to exist (Passed along to other IHttpHandlerFactory's)</param> 18
/// <returns> 19
/// Returns an Instance of IHttpHandler either by loading an instance of IHttpHandler or by returning an other 20
/// IHttpHandlerFactory.GetHanlder(HttpContext context, string requestType, string url, string path) method 21
/// </returns> 22
public virtual IHttpHandler GetHandler(HttpContext context, string requestType, string url, string path) 23
{ 24
//Get the Handlers to process. By defualt, we grab them from the blog.config 25
//Dottext.Framework.Logger.LogManager.Log("url",context.Request.Path); 26
HttpHandler[] items = GetHttpHandlers(context); 27
//Dottext.Framework.Logger.LogManager.Log("path",Dottext.Framework.Util.Globals.RemoveAppFromPath(context.Request.Path,context.Request.ApplicationPath)); 28
//Do we have any? 29
if(items != null) 30
{ 31
int count = items.Length; 32
33
for(int i = 0; i<count; i++) 34
{ 35
//We should use our own cached Regex. This should limit the number of Regex's created 36
//and allows us to take advantage of RegexOptons.Compiled 37
38
if(items[i].IsMatch(Dottext.Framework.Util.Globals.RemoveAppFromPath(context.Request.Path,context.Request.ApplicationPath))) 39
{ 40
//throw new Exception(); 41
switch(items[i].HandlerType) 42
{ 43
case HandlerType.Page://默认是Page 44
45
return ProccessHandlerTypePage(items[i],context,requestType,url); 46
case HandlerType.Direct: 47
HandlerConfiguration.SetControls(context,items[i].BlogControls); 48
return (IHttpHandler)items[i].Instance(); 49
case HandlerType.Factory: 50
//Pass a long the request to a custom IHttpHandlerFactory 51
return ((IHttpHandlerFactory)items[i].Instance()).GetHandler(context,requestType,url,path); 52
default: 53
throw new Exception("Invalid HandlerType: Unknown"); 54
} 55
} 56
} 57
} 58
//If we do not find the page, just let ASP.NET take over 59
return PageHandlerFactory.GetHandler(context,requestType,url, path); 60
} 61
62
63
private IHttpHandler ProccessHandlerTypePage(HttpHandler item, HttpContext context, string requestType, string url) 64
{ 65
string pagepath = item.FullPageLocation; 66
if(pagepath == null) 67
{ 68
pagepath = HandlerConfiguration.Instance().FullPageLocation; 69
} 70
HandlerConfiguration.SetControls(context,item.BlogControls); 71
IHttpHandler myhandler=PageParser.GetCompiledPageInstance(url,pagepath,context); 72
return myhandler; 73
} 74
75
76
public virtual void ReleaseHandler(IHttpHandler handler) 77
{ 78
79
} 80
}
81
代码很长，但是它是实现urlrewrite的关键，我们来分析分析看。
UrlReWriteHandlerFactory实现了IHttpHandlerFactory接口，而IHttpHandlerFactory最关键的地方在于GetHandler这个函数接口，所以我们从GetHandler函数入手。
首先是 HttpHandler [] items = GetHttpHandlers(context)； 通过查看GetHttpHandlers的定义，可以得知返回的其实是HandlerConfiguration中一个叫HttpHandlers的属性，它的值，是通过这么一句话来进行初始化的，return ((HandlerConfiguration)ConfigurationSettings.GetConfig("HandlerConfiguration")); 想必大家现在都明白了，HandlerConfiguration对象是通过将web.config中<HandlerConfiguration>节进行反序列化获得的，关于ConfigurationSettings.GetConfig的使用，网上已经有很多了，在这里就不重复劳动了。看看web.config中的HandlerConfiguration节
1
<
HandlerConfiguration
defaultPageLocation
="default.aspx"
type
="Dottext.Common.UrlManager.HandlerConfiguration, Dottext.Common"
>
2
<
HttpHandlers
>
3
<
HttpHandler
pattern
="(\.config|\.asax|\.ascx|\.config|\.cs|\.vb|\.vbproj|\.asp|\.licx|\.resx|\.resources)$"
type
="Dottext.Framework.UrlManager.HttpForbiddenHandler, Dottext.Framework"
handlerType
="Direct"
/>
4
<
HttpHandler
pattern
="(\.gif|\.js|\.jpg|\.zip|\.jpeg|\.jpe|\.css|\.rar|\.xml|\.xsl)$"
type
="Dottext.Common.UrlManager.BlogStaticFileHandler, Dottext.Common"
handlerType
="Direct"
/>
5
<
HttpHandler
pattern
="/rss\.aspx$"
type
="Dottext.Common.Syndication.RssHandler, Dottext.Common"
handlerType
="Direct"
/>
6
<
HttpHandler
pattern
="/CommentsRSS\.aspx$"
type
="Dottext.Common.Syndication.RecentCommentsRSS, Dottext.Common"
handlerType
="Direct"
/>
7
<
HttpHandler
pattern
= "/RecentCommentsRSS\.aspx$"
type
= "Dottext.Common.Syndication.RecentCommentsRSS, Dottext.Common"
handlerType
= "Direct"
/>
8
<
HttpHandler
pattern
="/atom\.aspx$"
type
="Dottext.Common.Syndication.AtomHandler, Dottext.Common"
handlerType
="Direct"
/>
9
<
HttpHandler
pattern
="/comments/commentRss/\d+\.aspx$"
type
="Dottext.Common.Syndication.RssCommentHandler, Dottext.Common"
handlerType
="Direct"
/>
10
<
HttpHandler
pattern
="/aggbug/\d+\.aspx$"
type
="Dottext.Framework.Tracking.AggBugHandler, Dottext.Framework"
handlerType
="Direct"
/>
11
<
HttpHandler
pattern
="/customcss\.aspx$"
type
="Dottext.Web.UI.Handlers.BlogSecondaryCssHandler, Dottext.Web"
handlerType
="Direct"
/>
12
<
HttpHandler
pattern
="/category\/(\d|\w|\s)+\.aspx/rss$"
type
="Dottext.Common.Syndication.RssCategoryHandler, Dottext.Common"
handlerType
="Direct"
/>
13
<
HttpHandler
pattern
="/favorite\/(\d|\w|\s)+\.aspx/rss$"
type
="Dottext.Common.Syndication.RssLinksHandler, Dottext.Common"
handlerType
="Direct"
/>
14
<
HttpHandler
pattern
="/articles/\d+\.aspx$"
controls
="viewpost.ascx,Comments.ascx,AnonymousPostComment.ascx,LoginPostComment.ascx"
/>
15
<
HttpHandler
pattern
="/articles/\w+\.aspx$"
controls
="viewpost.ascx,Comments.ascx,AnonymousPostComment.ascx,LoginPostComment.ascx"
/>
16
<
HttpHandler
pattern
="/PreviewPost.aspx$"
controls
="PreviewPost.ascx"
/>
17
<
HttpHandler
pattern
="/archive/\d{4}/\d{2}/\d{2}/\d+\.(aspx|htm)$"
controls
="viewpost.ascx,Comments.ascx,AnonymousPostComment.ascx,LoginPostComment.ascx"
/>
18
<
HttpHandler
pattern
="/archive/\d{4}/\d{2}/\d{2}/\w+\.(aspx|htm)$"
controls
="viewpost.ascx,Comments.ascx,AnonymousPostComment.ascx,LoginPostComment.ascx"
/>
19
<
HttpHandler
pattern
="/archive/\d{4}/\d{1,2}/\d{1,2}\.aspx$"
controls
="ArchiveDay.ascx"
/>
20
<
HttpHandler
pattern
="/archive/\d{4}/\d{1,2}\.aspx$"
controls
="ArchiveMonth.ascx"
/>
21
<
HttpHandler
pattern
="/archives/\d{4}/\d{1,2}\.aspx$"
controls
="ArticleArchiveMonth.ascx"
/>
22
<
HttpHandler
pattern
="/contact\.aspx$"
controls
="Contact.ascx"
/>
23
<
HttpHandler
pattern
="/AddToFavorite\.aspx$"
handlerType
="Page"
pageLocation
="AddToFavorite.aspx"
/>
24
<
HttpHandler
pattern
="/BlogSearch\.aspx$"
controls
="BlogSearch.ascx"
/>
25
<
HttpHandler
pattern
="/posts/|/story/|/archive/"
type
="Dottext.Web.UI.Handlers.RedirectHandler,Dottext.Web"
handlerType
="Direct"
/>
26
<
HttpHandler
pattern
="/gallery\/\d+\.aspx$"
controls
="GalleryThumbNailViewer.ascx"
/>
27
<
HttpHandler
pattern
="/gallery\/image\/\d+\.aspx$"
controls
="ViewPicture.ascx"
/>
28
<
HttpHandler
pattern
="/(?:category|stories)/(\w|\s)+\.aspx$"
controls
="CategoryEntryList.ascx"
/>
29
<
HttpHandler
pattern
="/favorite/(\w|\s)+\.aspx$"
controls
="FavoriteList.ascx"
/>
30
<
HttpHandler
pattern
="/(?:admin)"
type
="Dottext.Web.UI.Handlers.BlogExistingPageHandler, Dottext.Web"
handlerType
="Factory"
/>
31
<!--
<HttpHandler pattern = "^(?:\/(\w|\s|\.(?!aspx))+((\/login\.aspx)?|(\/?))?)$" type = "Dottext.Web.UI.Handlers.BlogExistingPageHandler, Dottext.Web" handlerType = "Factory" />
-->
32
<!--
<HttpHandler pattern = "^(?:/\w+\/(\w|\s|\.)+\/(?:admin|logout\.aspx|login\.aspx))" type = "Dottext.Web.UI.Handlers.BlogExistingPageHandler, Dottext.Web" handlerType = "Factory" />
-->
33
<
HttpHandler
pattern
="/comments\/\d+\.aspx$"
type
="Dottext.Common.Syndication.CommentHandler, Dottext.Common"
handlerType
="Direct"
/>
34
<
HttpHandler
pattern
="/services\/trackbacks/\d+\.aspx$"
type
="Dottext.Framework.Tracking.TrackBackHandler, Dottext.Framework"
handlerType
="Direct"
/>
35
<
HttpHandler
pattern
="/services\/pingback\.aspx$"
type
="Dottext.Framework.Tracking.PingBackService, Dottext.Framework"
handlerType
="Direct"
/>
36
<
HttpHandler
pattern
="/services\/metablogapi\.aspx$"
type
="Dottext.Framework.XmlRpc.MetaWeblog, Dottext.Framework"
handlerType
="Direct"
/>
37
<
HttpHandler
pattern
="/Services\/SyncHanlder\.aspx$"
handlerType
="Page"
pageLocation
="Sevices/DottextAPI.aspx"
/>
38
<!--
只显示文章标题列表
-->
39
<!--
<HttpHandler pattern="^((/default\.aspx)|(/)|(/index\.aspx))$" controls="CategoryPostsList.ascx" />
-->
40
<!--
显示文章内容
-->
41
<
HttpHandler
pattern
="^((/default\.aspx)|(/)|(/index\.aspx))$"
controls
="PagedPosts.ascx"
/>
42
<
HttpHandler
pattern
="^(/posts\.aspx)$"
controls
="PagedPosts.ascx"
/>
43
<!--
<HttpHandler pattern = "/services/\w+.asmx$" type="System.Web.Services.Protocols.WebServiceHandlerFactory, System.Web.Services, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" handlerType = "Factory" />
-->
44
<
HttpHandler
pattern
= "^(?:\/(\w|\s|\.(?!aspx))+((\/default\.aspx)?|(\/?))?)$"
controls
= "homepage.ascx"
/>
45
<!--
<HttpHandler pattern="^(?:/\w+\/(\w|\s|\.(?!aspx))+((\/default\.aspx)?|(\/?))?)$" controls="homepage.ascx" />
-->
46
47
</
HttpHandlers
>
48
</
HandlerConfiguration
>
49
<
HandlerConfiguration
defaultPageLocation
="default.aspx"
type
="Dottext.Common.UrlManager.HandlerConfiguration, Dottext.Common"
>
2
<
HttpHandlers
>
3
<
HttpHandler
pattern
="(\.config|\.asax|\.ascx|\.config|\.cs|\.vb|\.vbproj|\.asp|\.licx|\.resx|\.resources)$"
type
="Dottext.Framework.UrlManager.HttpForbiddenHandler, Dottext.Framework"
handlerType
="Direct"
/>
4
<
HttpHandler
pattern
="(\.gif|\.js|\.jpg|\.zip|\.jpeg|\.jpe|\.css|\.rar|\.xml|\.xsl)$"
type
="Dottext.Common.UrlManager.BlogStaticFileHandler, Dottext.Common"
handlerType
="Direct"
/>
5
<
HttpHandler
pattern
="/rss\.aspx$"
type
="Dottext.Common.Syndication.RssHandler, Dottext.Common"
handlerType
="Direct"
/>
6
<
HttpHandler
pattern
="/CommentsRSS\.aspx$"
type
="Dottext.Common.Syndication.RecentCommentsRSS, Dottext.Common"
handlerType
="Direct"
/>
7
<
HttpHandler
pattern
= "/RecentCommentsRSS\.aspx$"
type
= "Dottext.Common.Syndication.RecentCommentsRSS, Dottext.Common"
handlerType
= "Direct"
/>
8
<
HttpHandler
pattern
="/atom\.aspx$"
type
="Dottext.Common.Syndication.AtomHandler, Dottext.Common"
handlerType
="Direct"
/>
9
<
HttpHandler
pattern
="/comments/commentRss/\d+\.aspx$"
type
="Dottext.Common.Syndication.RssCommentHandler, Dottext.Common"
handlerType
="Direct"
/>
10
<
HttpHandler
pattern
="/aggbug/\d+\.aspx$"
type
="Dottext.Framework.Tracking.AggBugHandler, Dottext.Framework"
handlerType
="Direct"
/>
11
<
HttpHandler
pattern
="/customcss\.aspx$"
type
="Dottext.Web.UI.Handlers.BlogSecondaryCssHandler, Dottext.Web"
handlerType
="Direct"
/>
12
<
HttpHandler
pattern
="/category\/(\d|\w|\s)+\.aspx/rss$"
type
="Dottext.Common.Syndication.RssCategoryHandler, Dottext.Common"
handlerType
="Direct"
/>
13
<
HttpHandler
pattern
="/favorite\/(\d|\w|\s)+\.aspx/rss$"
type
="Dottext.Common.Syndication.RssLinksHandler, Dottext.Common"
handlerType
="Direct"
/>
14
<
HttpHandler
pattern
="/articles/\d+\.aspx$"
controls
="viewpost.ascx,Comments.ascx,AnonymousPostComment.ascx,LoginPostComment.ascx"
/>
15
<
HttpHandler
pattern
="/articles/\w+\.aspx$"
controls
="viewpost.ascx,Comments.ascx,AnonymousPostComment.ascx,LoginPostComment.ascx"
/>
16
<
HttpHandler
pattern
="/PreviewPost.aspx$"
controls
="PreviewPost.ascx"
/>
17
<
HttpHandler
pattern
="/archive/\d{4}/\d{2}/\d{2}/\d+\.(aspx|htm)$"
controls
="viewpost.ascx,Comments.ascx,AnonymousPostComment.ascx,LoginPostComment.ascx"
/>
18
<
HttpHandler
pattern
="/archive/\d{4}/\d{2}/\d{2}/\w+\.(aspx|htm)$"
controls
="viewpost.ascx,Comments.ascx,AnonymousPostComment.ascx,LoginPostComment.ascx"
/>
19
<
HttpHandler
pattern
="/archive/\d{4}/\d{1,2}/\d{1,2}\.aspx$"
controls
="ArchiveDay.ascx"
/>
20
<
HttpHandler
pattern
="/archive/\d{4}/\d{1,2}\.aspx$"
controls
="ArchiveMonth.ascx"
/>
21
<
HttpHandler
pattern
="/archives/\d{4}/\d{1,2}\.aspx$"
controls
="ArticleArchiveMonth.ascx"
/>
22
<
HttpHandler
pattern
="/contact\.aspx$"
controls
="Contact.ascx"
/>
23
<
HttpHandler
pattern
="/AddToFavorite\.aspx$"
handlerType
="Page"
pageLocation
="AddToFavorite.aspx"
/>
24
<
HttpHandler
pattern
="/BlogSearch\.aspx$"
controls
="BlogSearch.ascx"
/>
25
<
HttpHandler
pattern
="/posts/|/story/|/archive/"
type
="Dottext.Web.UI.Handlers.RedirectHandler,Dottext.Web"
handlerType
="Direct"
/>
26
<
HttpHandler
pattern
="/gallery\/\d+\.aspx$"
controls
="GalleryThumbNailViewer.ascx"
/>
27
<
HttpHandler
pattern
="/gallery\/image\/\d+\.aspx$"
controls
="ViewPicture.ascx"
/>
28
<
HttpHandler
pattern
="/(?:category|stories)/(\w|\s)+\.aspx$"
controls
="CategoryEntryList.ascx"
/>
29
<
HttpHandler
pattern
="/favorite/(\w|\s)+\.aspx$"
controls
="FavoriteList.ascx"
/>
30
<
HttpHandler
pattern
="/(?:admin)"
type
="Dottext.Web.UI.Handlers.BlogExistingPageHandler, Dottext.Web"
handlerType
="Factory"
/>
31
<!--
<HttpHandler pattern = "^(?:\/(\w|\s|\.(?!aspx))+((\/login\.aspx)?|(\/?))?)$" type = "Dottext.Web.UI.Handlers.BlogExistingPageHandler, Dottext.Web" handlerType = "Factory" />
-->
32
<!--
<HttpHandler pattern = "^(?:/\w+\/(\w|\s|\.)+\/(?:admin|logout\.aspx|login\.aspx))" type = "Dottext.Web.UI.Handlers.BlogExistingPageHandler, Dottext.Web" handlerType = "Factory" />
-->
33
<
HttpHandler
pattern
="/comments\/\d+\.aspx$"
type
="Dottext.Common.Syndication.CommentHandler, Dottext.Common"
handlerType
="Direct"
/>
34
<
HttpHandler
pattern
="/services\/trackbacks/\d+\.aspx$"
type
="Dottext.Framework.Tracking.TrackBackHandler, Dottext.Framework"
handlerType
="Direct"
/>
35
<
HttpHandler
pattern
="/services\/pingback\.aspx$"
type
="Dottext.Framework.Tracking.PingBackService, Dottext.Framework"
handlerType
="Direct"
/>
36
<
HttpHandler
pattern
="/services\/metablogapi\.aspx$"
type
="Dottext.Framework.XmlRpc.MetaWeblog, Dottext.Framework"
handlerType
="Direct"
/>
37
<
HttpHandler
pattern
="/Services\/SyncHanlder\.aspx$"
handlerType
="Page"
pageLocation
="Sevices/DottextAPI.aspx"
/>
38
<!--
只显示文章标题列表
-->
39
<!--
<HttpHandler pattern="^((/default\.aspx)|(/)|(/index\.aspx))$" controls="CategoryPostsList.ascx" />
-->
40
<!--
显示文章内容
-->
41
<
HttpHandler
pattern
="^((/default\.aspx)|(/)|(/index\.aspx))$"
controls
="PagedPosts.ascx"
/>
42
<
HttpHandler
pattern
="^(/posts\.aspx)$"
controls
="PagedPosts.ascx"
/>
43
<!--
<HttpHandler pattern = "/services/\w+.asmx$" type="System.Web.Services.Protocols.WebServiceHandlerFactory, System.Web.Services, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" handlerType = "Factory" />
-->
44
<
HttpHandler
pattern
= "^(?:\/(\w|\s|\.(?!aspx))+((\/default\.aspx)?|(\/?))?)$"
controls
= "homepage.ascx"
/>
45
<!--
<HttpHandler pattern="^(?:/\w+\/(\w|\s|\.(?!aspx))+((\/default\.aspx)?|(\/?))?)$" controls="homepage.ascx" />
-->
46
47
</
HttpHandlers
>
48
</
HandlerConfiguration
>
49
其实在visual studio.net中看这段代码会更加清楚一点，这里的每一个pattern其实都会建立对应的Regex ，来对用户请求的url进行匹配，下面的代码会很详细说明这一点，我们往下看。
接下来是一个循环，循环中执行这么一句话
if (items[i].IsMatch(Dottext.Framework.Util.Globals.RemoveAppFromPath(context.Request.Path,context.Request.ApplicationPath))) {...}
它把web.config中每一个httphandler来匹配用户的请求，IsMatch函数中会根据pattern建立相应的Regex，并调用Regex.IsMatch函数，如果请求匹配该pattern，则调用对应的模块来进行处理。很显然，这里是实现urlrewrite的关键之处，比如，请求的是这么一个url
http://oop80.cnblogs.com/archive/2005/08/09/210550.html
那么，他就会匹配这一个handler
<HttpHandler pattern="/archive/\d{4}/\d{2}/\d{2}/\d+\.(aspx|htm)$" controls="viewpost.ascx,Comments.ascx,AnonymousPostComment.ascx,LoginPostComment.ascx" />
那么，程序就会调用 viewpost.ascx,Comments.ascx,AnonymousPostComment.ascx,LoginPostComment.ascx 来处理用户的请求，
又如，请求这么一个url
http://oop80.cnblogs.com/category/23435.aspx
匹配
<HttpHandler pattern="/(?:category|stories)/(\w|\s)+\.aspx$" controls="CategoryEntryList.ascx" />
最后程序是一个switch语句，根据handlertype的不同进行各种处理，具体就不在解释了，因为……这一段我自己也没有进行更深入一步的研究，里面还有一些细节，如SetControls的控件在什么地方载入，GetCompiledPageInstance函数的具体用法等等。不过，这些东西终归和urlrewrite没多大关系了，不在我们讨论的范围之内。
请大家多多指教，谢谢