WebMethodAttribute Constructor (Boolean, TransactionOption, Int32, Boolean)

Initializes a new instance of the WebMethodAttribute class.

Namespace:  System.Web.Services
Assembly:  System.Web.Services (in System.Web.Services.dll)

public WebMethodAttribute(
	bool enableSession,
	TransactionOption transactionOption,
	int cacheDuration,
	bool bufferResponse


Type: System.Boolean

Initializes whether session state is enabled for the XML Web service method.

Type: System.EnterpriseServices.TransactionOption

Initializes the transaction support of an XML Web service method.

Type: System.Int32

Initializes the number of seconds the response is cached.

Type: System.Boolean

Initializes whether the response for this request is buffered.

A web service call can only be the root of a transaction, due to the stateless nature of the HTTP protocol. This means that the following two settings are equivalent, with each call creating a new transaction:

[WebMethod(TransactionOption = TransactionOption.Required)]
[WebMethod(TransactionOption = TransactionOption.RequiresNew)]

It also means that all the following settings are equivalent; meaning no transaction support:

[WebMethod] // TransactionOption.Disabled is the default
[WebMethod(TransactionOption = TransactionOption.Disabled)]
[WebMethod(TransactionOption = Transaction.NotSupported)]
[WebMethod(TransactionOption = Transaction.Supported)]

<%@WebService class="Streaming" language="C#"%>
<%@ assembly name="System.EnterpriseServices,Version=1.0.3300.0,Culture=neutral,PublicKeyToken=b03f5f7f11d50a3a" %>

using System;
using System.IO;
using System.Collections;
using System.Xml.Serialization;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.EnterpriseServices;

public class Streaming {

    public TextFile GetTextFile(string filename) {
        return new TextFile(filename);

    public void CreateTextFile(TextFile contents) {


public class TextFile {
    public string filename;
    private TextFileReaderWriter readerWriter;

    public TextFile() {

    public TextFile(string filename) {
        this.filename = filename;

    public TextFileReaderWriter contents {
        get {
            readerWriter = new TextFileReaderWriter(filename);
            return readerWriter;

    public void Close() {
        if (readerWriter != null) readerWriter.Close();

public class TextFileReaderWriter : IEnumerable {

    public string Filename;
    private StreamWriter writer;

    public TextFileReaderWriter() {

    public TextFileReaderWriter(string filename) {
        Filename = filename;

    public TextFileEnumerator GetEnumerator() {
        StreamReader reader = new StreamReader(Filename);
        return new TextFileEnumerator(reader);

    IEnumerator IEnumerable.GetEnumerator() {
        return GetEnumerator();

    public void Add(string line) {
        if (writer == null)
            writer = new StreamWriter(Filename);

    public void Close() {
        if (writer != null) writer.Close();


public class TextFileEnumerator : IEnumerator {
    private string currentLine;
    private StreamReader reader;

    public TextFileEnumerator(StreamReader reader) {
        this.reader = reader;

    public bool MoveNext() {
        currentLine = reader.ReadLine();
        if (currentLine == null) {
            return false;
            return true;

    public void Reset() {
        reader.BaseStream.Position = 0;

    public string Current {
        get {
            return currentLine;

    object IEnumerator.Current {
        get {
            return Current;

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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