Ajax. NET User Development Guide (5)

Ajax| Development Guide

[Ajax.ajaxmethod] public string Test1 (string name, string email, string comment) { String html = ""; HTML + + "Hello" + name + " "; html = "Thank for your comment "; HTML + System.Web.HttpUtility.HtmlEncode (comment); HTML + = "."; return HTML; }

SessionState

In the service-side function, you may need to accept the delivered session information, in order to do this, you must pass a parameter on the Ajax.ajaxmethod attribute of the service-side function that you want to implement this way .

When looking at Ajax to support the session, let's look at other features first. . In the following example, we have a document management system that locks the document when a user edits it, and other users need to wait until the document is available to modify . Without Ajax, users need to keep waiting to refresh because they have to constantly check that the status of the document is available, which is certainly not a good solution. . It's easier to support it with the AJAX session state .

We first write a function that, by traversing the document ID, finds the document that the user needs, stores it in the session, and returns the document that is not occupied:

' VB.net httpsessionstaterequirement.read) > _ Public Function documentreleased () as ArrayList If HttpContext.Current.Session ("documentswaiting") is nothing Then Return Nothing End If Dim readydocuments as New ArrayList Dim documents () As Integer = CType (HttpContext.Current.Session ("documentswaiting"), Integer ()) For I as an Integer = 0 to documents. Length-1 Dim Document as document = document. Getdocumentbyid (Documents (i)) If not the document is nothing AndAlso document. Status = Documentstatus.ready Then Readydocuments.add (document) End If Next Return readydocuments End Function

C# [Ajax.ajaxmethod (httpsessionstaterequirement.read)] Public ArrayList documentreleased () { if (httpcontext.current.session["documentswaiting"] = = null) { return null; } ArrayList readydocuments = new ArrayList (); int[] documents = (int[]) httpcontext.current.session["documentswaiting"]; for (int i = 0; I documents. Length; ++i) { Document document = Document.getdocumentbyid (Documents[i]); if (document!= null && document. Status = = Documentstatus.ready) { Readydocuments.add (document); } } return readydocuments; } }

We indicated the httpsessionstaterequirement.read in the attribute argument (also can be write and ReadWrite)

The following writes the JavaScript function to use this method to bring the result:

Every 10 seconds after the page is loaded, the server function is requested once . If there is a return, the call back function checks the response and displays the latest results .

　Conclusion

Ajax technology can provide a rich customer experience for clients, and Ajax.NET provides the possibility for you to achieve such powerful functionality easily.

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