application|session| object with ASP to write virtual community, online shopping and other programs, application and session object plays a pivotal role, the flexibility and reasonable use of these two objects is the key to improve the quality of the program. The following let the author according to their own experience in this area, to you in-depth introduction of the ASP's two built-in objects.
Overview of members of a Application object
Application object members include collections, methods, and events for application objects.
Collection of ⒈application objects
Contents collection: A collection of all variables stored in Applicaiton objects that are not defined using the <OBJECT> element
StaticObjects: A collection of all the variables stored in the Application object, defined using the <OBJECT> element
Example: The following assignment is available in the Default.asp
Application ("a") = "a"
Application ("B") =128
Application ("C") =false
Then there are contents sets
Application.Contents (1) = "A" can also be written as application.contents ("a") = "a"
Application.Contents (2) =128 ' can also be written as application.contents ("B") =128
Application.Contents (3) =false ' can also be written as application.contents ("C") =false
In this article I recommend that you use classes such as Application.Contents ("a") in the call, because this is more intuitive, if the number of words to consider the order of assignment.
Methods of ⒉application objects
Contents.Remove ("Variable name"): Removes the specified variable from the Application.Contents collection
Contents.RemoveAll (): Remove all variables from the Application.Contents collection
Lock (): Locks the Application object so that only the current ASP page can access the content
Unlock (): Unlocking the Application object
Example: In the Default.asp:
Application ("a") = "a"
Application ("B") =128
Application ("C") =false
Response.Write application.contents (1) & "<br>"
Response.Write Application.Contents (2) & "<br>"
Response.Write Application.Contents (3) & "<br>"
Response.Write "after Remove B:"
Application.Contents.Remove ("B")
Response.Write application.contents (1) & "<br>"
Response.Write Application.Contents (2) & "<br>"
Execution results:
A
128
False
After Remove B:
A
False
If you want to delete all the variables in the collection with Application.contents.removeall, the lock and unlock methods are often used in practice, and the reader is more familiar with it.
⒊application Object Events
OnStart: The first time a user accessing a server occurs when a page is first accessed
OnEnd: When the last user's session has ended and the session's OnEnd event has been completed, or the last user accesses the server for a period of time (typically 20 minutes), no one has access to the server.
What you want to define in the OnStart and OnEnd events of the Application object is to write the code in the Global.asa file (for an example below) and place the file in the root directory of the site (typically inetpub\wwwroot\)
