Several methods to obtain the absolute path of a website in ASP. NET

Compile an ASP. NET applicationProgramSometimes, to better control the path of static files, such as setting the path of JS or CSS files on the template page or user control, it is inevitable to use absolute paths. The following are several methods to obtain absolute paths.

C # Code Virtualpathutility. toabsolute (
"
~ /
"
)
Httpruntime. appdomainappvirtualpath
Request. applicationpath
Page. resolveurl (
"
~
"
)

The result of the above Code is as follows:
When accessing a website, the result is as follows:

Virtualpathutility. toabsolute ("~ /")	=/
Httpruntime. appdomainappvirtualpath	=/
Request. applicationpath	=/
Page. resolveurl ("~ ")	=/

When you use a virtual directory (http: // localhost: 806/web2/url. aspx), the result is as follows:

Virtualpathutility. toabsolute ("~ /")	=/Web2/
Httpruntime. appdomainappvirtualpath	=/Web2
Request. applicationpath	=/Web2
Page. resolveurl ("~ ")	=/Web2/

The second and third methods also need to be processed, because the Website access ends with a slash (/), but the access to a virtual directory does not contain a slash (/), and a judgment is required, A little effort.
However, there is no problem in using these methods on the page, but if you need to obtain the absolute path of the website in the global application_start event, you need to use the first two methods, if the third method is used, the following error is reported:
Request is not available in this context

Therefore, you can only use the first two methods. For example

C # code Void
Application_start (
Object
Sender, eventargs E)
{
System. Io. streamwriter s
=

New
System. Io. streamwriter (httpruntime. appdomainapppath
+

"
Log.txt
"
);
S. writeline (virtualpathutility. toabsolute (
"
~ /
"
));
S. writeline (httpruntime. appdomainappvirtualpath );
S. Close ();
}