WCF/REST Something is up with my POST?

Question

When I POST using my windows form app (second peace of code down) when I go to GET the student collection with buttonclick 2 into my datagrid nothing is showing I can hardcode the members and GET no problem, yet I cant POST? The response I get back says OK in the message box when I click button1 for my post? So not quite sure what I have done...

    [WebInvoke(Method = "POST", BodyStyle = WebMessageBodyStyle.Bare, RequestFormat = WebMessageFormat.Xml, ResponseFormat = WebMessageFormat.Xml, UriTemplate = "")]
    void AddStudent(Student student);

            XDocument xDoc = XDocument.Load(uri);
            var students = xDoc.Descendants("Student")
                .Select(n => new
                {
                    StudentNo = n.Element("StudentID").Value,
                    Firstname = n.Element("FirstName").Value,
                    Surname = n.Element("LastName").Value
                })
                .ToList();

            dataGridView1.DataSource = students;
        }

Be consistent with naming `StudentID` or `StudentNo`, `FirstName` or `Firstname`, `LastName` or `Surname` — L.B, Apr 05 '12 at 20:14
hey Denis this is purely for visual representation to the user — G Gr, Apr 05 '12 at 20:17
Is the `var students ` populated? If so, try using [BindingContext](http://stackoverflow.com/a/3481908/884410) — Raj Ranjhan, Apr 05 '12 at 20:20
That method doesnt work still the same return of the 3 students. Im not sure if its my addstudent in my operationcontract thats doing it? — G Gr, Apr 05 '12 at 20:26
In your similar [question](http://stackoverflow.com/questions/10033743/xml-to-listbox-from-webservice/10034789#10034789) I see that your xml's root element is `ArrayOfStudent`. Why do you form your xml manually instead of using an xml parser? what is the use of `Student` class if you don't use it for serializing/deserializing ? — L.B, Apr 05 '12 at 20:29
Are you sure that you form your xml correctly? Maybe it should have a root tag as `ArrayOfStudent` not `Student` — L.B, Apr 05 '12 at 20:35
Using string builder to form an xml is a bad idea. Use Xml Parsers like XmlDocument, XDocument etc. — L.B, Apr 05 '12 at 20:38
You can also use XmlSerializer to serialize your `Student` class to get the xml to post to server. — L.B, Apr 05 '12 at 20:39

score 1 · Accepted Answer · answered Apr 06 '12 at 01:24

1

Are you running in Per Call Activation mode? If so, every client request gets a new dedicated service instance, so your List<> is being recreated as empty every time.

See this reference article. You'll have to persist your List between calls, either in a Cache or Database.

answered Apr 06 '12 at 01:24

mgnoonan

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GOD! That was so much reading to find the answer which ofcourse I knew it would be a one line sort of thing: `[ServiceBehavior(InstanceContextMode = InstanceContextMode.Single)]` – G Gr Apr 06 '12 at 01:57

Raj Ranjhan · Answer 2 · 2012-04-06T03:54:25.680

0

Your AddStudent is not adding to the list

public void AddStudent(Student student)
{
    student.StudentID.ToString();
    student.FirstName.ToString();
    student.LastName.ToString();
}

And GetStudentCollection is returning the same hard coded values.

static List<Student> students = new List<Student>();
public void AddStudent(Student student)
{
   students.Add(student);

}

public List<Student> GetStudentCollection()
{
    return students;
}

edited Apr 06 '12 at 03:54

answered Apr 05 '12 at 20:28

Raj Ranjhan

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still nothing returned, no errors either? Btw I had this originally but I also wanted the hardcoded members (for easeness) – G Gr Apr 05 '12 at 20:43
Then there may be other issues also. Your `Addstudent` is probably not working correctly. Can you put a breakpoint there and see if is being called with a properly formatted student? – Raj Ranjhan Apr 05 '12 at 20:49

score 0 · Answer 3 · answered Apr 05 '12 at 20:37

0

Your service is doing exactly what you wrote in code. ListStudents constantly returns the same list of the students, AddStudent do nothing with the list.

answered Apr 05 '12 at 20:37

paramosh

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WCF/REST Something is up with my POST?

3 Answers3