AJAX reference PageMethod method description in ASP. NET 3.5

Sometimes, we need to use the post-commit method on the page's response surface. The following method can be implemented.

1. Using AJAX to support the response.

Add the following labels to the system. web tag of web. config:

 

Code

<HttpHandlers>
<Add verb = "GET, HEAD" path = "ScriptResource. axd "type =" System. web. handlers. scriptResourceHandler, System. web. extensions, Version = 3.5.0.0, Culture = neutral, PublicKeyToken = 31BF3856AD364E35 "validate =" false "/>
</HttpHandlers>
<HttpModules>
<Add name = "ScriptModule" type = "System. Web. Handlers. ScriptModule, System. Web. Extensions, Version = 3.5.0.0, Culture = neutral, PublicKeyToken = 31BF3856AD364E35"/>
</HttpModules>

 

 

2. Use the EnablePageMethod annotation of ScriptManage.

 

ScriptManager. GetCurrent (Page). EnablePageMethods = true;

 

 

3. Add the method to be used in future generation.

Ps: Add webmethod and static.

Code

[System. Web. Services. WebMethod]
Public static DataTable GetData (string empno, string cname)
{
Try
{
DataTable dt = new DataTable ();
Dt. Columns. Add (new DataColumn (empno, typeof (string )));
Dt. Columns. Add (new DataColumn (cname, typeof (string )));
Return dt;
}
Catch
{
Return null;
}
}

 

 

4. Use this method in javascript on the page.

 

Code

Function GetData (){
PageMethods. GetData (
Document. getElementById ("<% = TextBox_EmpNo.ClientID %>"). value,
Document. getElementById ("<% = TextBox_CName.ClientID %>"). value,
OnSuccess );
}
Function onSuccess (result ){
If (result! = Null ){
Var dt = result;
If (dt! = Null & typeof (dt) = "object "){
Var innerHtml = new Sys. StringBuilder ("<OL> ");
For (var I = 0; I <dt. rows. length; I ++ ){
Var empid = dt. rows [I]. employee_id;
Var chname = dt. rows [I]. chname;
InnerHtml. append (String. format ("<LI> <INPUT type = 'checkbox' id = 'all _ {0}, {1} <BR> {2} '> {3 }, {4} <br >{5} </LI> ", chname, empid, email, chname, empid, email ));
}
InnerHtml. append ("</OL> ");
Document. getElementById ("PH"). innerHTML = innerHtml;
}
}
Else {
Alert ("Error ");
Return false;
}
}
Function onFailed (error ){
Alert (error. get_message ());
}

 

 

PS: note that the PageMethods class is generated by the system's automatic token, which records all webmethod methods in the class.

 

Code

The method for using PageMethods volumes is as follows:
PageMethods. [MethodName] (parameter1, parameter2 ,..., SuccessMethod, FailedMethod, userContext );
Where
Parameter? To match the Server.
SuccessMethod, required. Number of response letters when WebMethod is correctly returned. The prototype is onSuccess (result ).
FailedMethod, not required. WebMethod returns the response number when the response is returned, which is an onFailed (error ).
 

 

 

After the preceding steps are completed, if the method used by the consumer returns a data type other than DataSet, able, and DataRow, then the result will be displayed.

However, if DataSet, able, or DataRow is returned, a response is returned.

 

A circular reference was detected while serializing an object...

 

Microsoft also knows this question.

Http://connect.microsoft.com/VisualStudio/feedback/details/535133/error-a-circular-reference-was-detected-while-serializing-an-object-of-type-system-data-dataview

However, no specific solution was provided.

The solutions found on the Internet are as follows:

1. download AJAX Futures CTP from the microsoft website

Http://www.microsoft.com/downloads/details.aspx? FamilyID = 4cb52ea3-9548-4064-8137-09b96af97617 & displaylang = en

2. copy the Microsoft. Web. Preview. dll file to the bin directory of the project.

3. modify web. config and add the following labels.

 

Code

<System. web. extensions>
<Scripting>
<WebServices>
<JsonSerialization maxJsonLength = "500000000">
<Converters>
<Add name = "DataSetConverter" type = "Microsoft. web. preview. script. serialization. converters. dataSetConverter, Microsoft. web. preview, Version = 1.0.61025.0, Culture = neutral, PublicKeyToken = 31bf3856ad364e35 "/>
<Add name = "DataRowConverter" type = "Microsoft. web. preview. script. serialization. converters. dataRowConverter, Microsoft. web. preview, Version = 1.0.61025.0, Culture = neutral, PublicKeyToken = 31bf3856ad364e35 "/>
<Add name = "DataTableConverter" type = "Microsoft. web. preview. script. serialization. converters. dataTableConverter, Microsoft. web. preview, Version = 1.0.61025.0, Culture = neutral, PublicKeyToken = 31bf3856ad364e35 "/>
</Converters>
</JsonSerialization>
</WebServices>
</Scripting>
</System. web. extensions>

 

 

This solves the problem.