HttpRequest Class

Reference

Definition

Namespace:: System.Web

Assembly:: System.Web.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Enables ASP.NET to read the HTTP values sent by a client during a Web request.

public ref class HttpRequest sealed

public sealed class HttpRequest

type HttpRequest = class

Public NotInheritable Class HttpRequest

Inheritance: Object
HttpRequest

Examples

The following examples access the HttpRequest instance for the current request by using the Request property of the Page class.

You can use simplified syntax for accessing data from the QueryString, Form, Cookies, or ServerVariables collections. You can write Request["key"].

The first example shows how to retrieve a query string value when loading a page.

public partial class AddToCart : Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        string rawId = Request["ProductID"];
        int productId;
        if (!String.IsNullOrEmpty(rawId) && int.TryParse(rawId, out productId))
        {
            using (ShoppingCartActions usersShoppingCart = new ShoppingCartActions())
            {
                usersShoppingCart.AddToCart(productId);
            }
        }
        else
        {
            throw new Exception("Tried to call AddToCart.aspx without setting a ProductId.");
        }
        Response.Redirect("ShoppingCart.aspx");
    }
}

Public Class AddToCart
    Inherits Page

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
        Dim rawId = Request("ProductID")
        Dim productId As Integer
        If Not String.IsNullOrEmpty(rawId) And Integer.TryParse(rawId, productId) Then
            Using usersShoppingCart As New ShoppingCartActions()
                usersShoppingCart.AddToCart(productId)
            End Using

        Else
            Throw New Exception("Tried to call AddToCart.aspx without setting a ProductId.")
        End If
        Response.Redirect("ShoppingCart.aspx")
    End Sub
End Class

The next example shows how to check if the request is authenticated and retrieve the raw URL.

public partial class RestrictedPage : Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!Request.IsAuthenticated)
        {
            var rawUrl = Request.RawUrl;
            Response.Redirect("/Account/Login?ru=" + Server.HtmlEncode(rawUrl));
        }
    }
}

Public Class RestrictedPage
    Inherits Page

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
        If Not Request.IsAuthenticated Then
            Dim rawUrl = Request.RawUrl
            Response.Redirect("/Account/Login?ru=" + Server.HtmlEncode(rawUrl))
        End If
    End Sub
End Class

A Visual Studio Web site project with source code is available to accompany this topic: Download.

This example uses the StreamWriter class to write the values of several HttpRequest class properties to a file. For properties that are of type string, the values are HTML encoded as they are written to the file. Properties that represent a collection are looped through, and each key/value pair that they contain is written to the file.

Important

This example has a text box that accepts user input, which is a potential security threat. By default, ASP.NET Web pages validate that user input does not include script or HTML elements. For more information, see Script Exploits Overview.

<%@ Page Language="C#" %>
<%@ import Namespace="System.Threading" %>
<%@ import Namespace="System.IO" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

    /* NOTE: To use this sample, create a c:\temp\CS folder,
    *  add the ASP.NET account (in IIS 5.x <machinename>\ASPNET,
    *  in IIS 6.x NETWORK SERVICE), and give it write permissions
    *  to the folder.*/

    private const string INFO_DIR = @"c:\temp\CS\RequestDetails";
    public static int requestCount;

    private void Page_Load(object sender, System.EventArgs e)
    {

        // Create a variable to use when iterating
        // through the UserLanguages property.
        int langCount;

        int requestNumber = Interlocked.Increment(ref requestCount);

        // Create the file to contain information about the request.
        string strFilePath = INFO_DIR + requestNumber.ToString() + @".txt";


        StreamWriter sw = File.CreateText(strFilePath);

        try
        {
// <snippet2>
            // Write request information to the file with HTML encoding.
            sw.WriteLine(Server.HtmlEncode(DateTime.Now.ToString()));
            sw.WriteLine(Server.HtmlEncode(Request.CurrentExecutionFilePath));
            sw.WriteLine(Server.HtmlEncode(Request.ApplicationPath));
            sw.WriteLine(Server.HtmlEncode(Request.FilePath));
            sw.WriteLine(Server.HtmlEncode(Request.Path));
// </snippet2>

// <snippet3>
            // Iterate through the Form collection and write
            // the values to the file with HTML encoding.
            // String[] formArray = Request.Form.AllKeys;
            foreach (string s in Request.Form)
            {
                sw.WriteLine("Form: " + Server.HtmlEncode(s));
            }
// </snippet3>

// <snippet4>
            // Write the PathInfo property value
            // or a string if it is empty.
            if (Request.PathInfo == String.Empty)
            {
                sw.WriteLine("The PathInfo property contains no information.");
            }
            else
            {
                sw.WriteLine(Server.HtmlEncode(Request.PathInfo));
            }
// </snippet4>

// <snippet5>
            // Write request information to the file with HTML encoding.
            sw.WriteLine(Server.HtmlEncode(Request.PhysicalApplicationPath));
            sw.WriteLine(Server.HtmlEncode(Request.PhysicalPath));
            sw.WriteLine(Server.HtmlEncode(Request.RawUrl));
// </snippet5>

// <snippet6>
            // Write a message to the file dependent upon
            // the value of the TotalBytes property.
            if (Request.TotalBytes > 1000)
            {
                sw.WriteLine("The request is 1KB or greater");
            }
            else
            {
                sw.WriteLine("The request is less than 1KB");
            }
// </snippet6>

// <snippet7>
            // Write request information to the file with HTML encoding.
            sw.WriteLine(Server.HtmlEncode(Request.RequestType));
            sw.WriteLine(Server.HtmlEncode(Request.UserHostAddress));
            sw.WriteLine(Server.HtmlEncode(Request.UserHostName));
            sw.WriteLine(Server.HtmlEncode(Request.HttpMethod));
// </snippet7>

// <snippet8>
            // Iterate through the UserLanguages collection and
            // write its HTML encoded values to the file.
            for (langCount=0; langCount < Request.UserLanguages.Length; langCount++)
            {
                sw.WriteLine(@"User Language " + langCount +": " + Server.HtmlEncode(Request.UserLanguages[langCount]));
            }
// </snippet8>
       }

       finally
       {
            // Close the stream to the file.
            sw.Close();
       }

        lblInfoSent.Text = "Information about this request has been sent to a file.";
    }


    private void btnSendInfo_Click(object sender, System.EventArgs e)
    {
        lblInfoSent.Text = "Hello, " + Server.HtmlEncode(txtBoxName.Text) +
          ". You have created a new  request info file.";
    }

</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
    <title>ASP.NET Example</title>
</head>
<body>
    <form id="form1" runat="server">
        <p>
        </p>
        <p>
            Enter your name here:
            <asp:TextBox id="txtBoxName" runat="server"></asp:TextBox>
        </p>
        <p>
            <asp:Button id="btnSendInfo" onclick="btnSendInfo_Click" runat="server" Text="Click Here"></asp:Button>
        </p>
        <p>
            <asp:Label id="lblInfoSent" runat="server"></asp:Label>
        </p>
    </form>
</body>
</html>

<%@ Page Language="VB" %>
<%@ import Namespace="System.Threading" %>
<%@ import Namespace="System.IO" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">

    '  NOTE: To use this sample, create a c:\temp\CS folder,
    '  add the ASP.NET account (in IIS 5.x <machinename>\ASPNET,
    '  in IIS 6.x NETWORK SERVICE), and give it write permissions
    '  to the folder.

    Private Const INFO_DIR As String = "c:\temp\VB\RequestDetails"
    Public Shared requestCount As Integer

    Private Sub Page_Load(sender As Object, e As System.EventArgs)

        ' Create a variable to use when iterating
        ' through the UserLanguages property.
        Dim langCount As Integer

        ' Create a counter to name the file.
        Dim requestNumber As Integer = _
          Interlocked.Increment(requestCount)

        ' Create the file to contain information about the request.
        Dim strFilePath As String = INFO_DIR & requestNumber.ToString() & ".txt"
        Dim sw As StreamWriter = File.CreateText(strFilePath)

        Try

' <snippet2>
            ' Write request information to the file with HTML encoding.
            sw.WriteLine(Server.HtmlEncode(DateTime.Now.ToString()))
            sw.WriteLine(Server.HtmlEncode(Request.CurrentExecutionFilePath))
            sw.WriteLine(Server.HtmlEncode(Request.ApplicationPath))
            sw.WriteLine(Server.HtmlEncode(Request.FilePath))
            sw.WriteLine(Server.HtmlEncode(Request.Path))
' </snippet2>

' <snippet3>
            ' Iterate through the Form collection and write
            ' the values to the file with HTML encoding.
            For Each s As String In Request.Form
                sw.WriteLine("Form: " & Server.HtmlEncode(s))
            Next s
' </snippet3>

' <snippet4>
            ' Write the PathInfo property value
            ' or a string if it is empty.
            If Request.PathInfo = String.Empty Then
                sw.WriteLine("The PathInfo property contains no information.")
            Else
                sw.WriteLine(Server.HtmlEncode(Request.PathInfo))
            End If
' </snippet4>

' <snippet5>
            ' Write request information to the file with HTML encoding.
            sw.WriteLine(Server.HtmlEncode(Request.PhysicalApplicationPath))
            sw.WriteLine(Server.HtmlEncode(Request.PhysicalPath))
            sw.WriteLine(Server.HtmlEncode(Request.RawUrl))
' </snippet5>

' <snippet6>
            ' Write a message to the file dependent upon
            ' the value of the TotalBytes property.
            If Request.TotalBytes > 1000 Then
                sw.WriteLine("The request is 1KB or greater")
            Else
                sw.WriteLine("The request is less than 1KB")
            End If
' </snippet6>

' <snippet7>
            ' Write request information to the file with HTML encoding.
            sw.WriteLine(Server.HtmlEncode(Request.RequestType))
            sw.WriteLine(Server.HtmlEncode(Request.UserHostAddress))
            sw.WriteLine(Server.HtmlEncode(Request.UserHostName))
            sw.WriteLine(Server.HtmlEncode(Request.HttpMethod))
' </snippet7>

' <snippet8>
            ' Iterate through the UserLanguages collection and
            ' write its HTML encoded values to the file.
            For langCount = 0 To Request.UserLanguages.Length - 1
                sw.WriteLine("User Language " & langCount.ToString() & _
                 ": " & Server.HtmlEncode( _
                     Request.UserLanguages(langCount)))
            Next
' </snippet8>

        Finally
            ' Close the stream to the file.
            sw.Close()
        End Try

        lblInfoSent.Text = _
         "Information about this request has been sent to a file."
    End Sub 'Page_Load



    Private Sub btnSendInfo_Click(sender As Object, e As System.EventArgs)
        lblInfoSent.Text = _
         "Hello, " & Server.HtmlEncode(txtBoxName.Text) & _
          ". You have created a new  request info file."
    End Sub 'btnSendInfo_Click

</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
    <title>ASP.NET Example</title>
</head>
<body>
    <form id="form1" runat="server">
        <p>
        </p>
        <p>
            Enter your name here:
            <asp:TextBox id="txtBoxName" runat="server"></asp:TextBox>
        </p>
        <p>
            <asp:Button id="btnSendInfo" onclick="btnSendInfo_Click" runat="server" Text="Click Here"></asp:Button>
        </p>
        <p>
            <asp:Label id="lblInfoSent" runat="server"></asp:Label>
        </p>
    </form>
</body>
</html>

Remarks

The methods and properties of the HttpRequest class are exposed through the Request properties of the HttpApplication, HttpContext, Page, and UserControl classes.

To access data from the QueryString, Form, Cookies, or ServerVariables collections, you can write Request["key"], as shown in the example for the QueryString property.

Note

Unicode support for HttpRequest class members requires IIS version 6.0 or later.

Constructors

HttpRequest(String, String, String)

Initializes an HttpRequest object.

Properties

AcceptTypes	Gets a string array of client-supported MIME accept types.
AnonymousID	Gets the anonymous identifier for the user, if present.
ApplicationPath	Gets the ASP.NET application's virtual application root path on the server.
AppRelativeCurrentExecutionFilePath	Gets the virtual path of the application root and makes it relative by using the tilde (~) notation for the application root (as in "~/page.aspx").
Browser	Gets or sets information about the requesting client's browser capabilities.
ClientCertificate	Gets the current request's client security certificate.
ContentEncoding	Gets or sets the character set of the entity-body.
ContentLength	Specifies the length, in bytes, of content sent by the client.
ContentType	Gets or sets the MIME content type of the incoming request.
Cookies	Gets a collection of cookies sent by the client.
CurrentExecutionFilePath	Gets the virtual path of the current request.
CurrentExecutionFilePathExtension	Gets the extension of the file name that is specified in the CurrentExecutionFilePath property.
FilePath	Gets the virtual path of the current request.
Files	Gets the collection of files uploaded by the client, in multipart MIME format.
Filter	Gets or sets the filter to use when reading the current input stream.
Form	Gets a collection of form variables.
Headers	Gets a collection of HTTP headers.
HttpChannelBinding	Gets the ChannelBinding object of the current HttpWorkerRequest instance.
HttpMethod	Gets the HTTP data transfer method (such as `GET`, `POST`, or `HEAD`) used by the client.
InputStream	Gets the contents of the incoming HTTP entity body.
IsAuthenticated	Gets a value indicating whether the request has been authenticated.
IsLocal	Gets a value indicating whether the request is from the local computer.
IsSecureConnection	Gets a value indicating whether the HTTP connection uses secure sockets (that is, HTTPS).
Item[String]	Gets the specified object from the QueryString, Form, Cookies, or ServerVariables collections.
LogonUserIdentity	Gets the WindowsIdentity type for the current user.
Params	Gets a combined collection of QueryString, Form, Cookies, and ServerVariables items.
Path	Gets the virtual path of the current request.
PathInfo	Gets the additional path information for a resource with a URL extension.
PhysicalApplicationPath	Gets the physical file system path of the currently executing server application's root directory.
PhysicalPath	Gets the physical file system path corresponding to the requested URL.
QueryString	Gets the collection of HTTP query string variables.
RawUrl	Gets the raw URL of the current request.
ReadEntityBodyMode	Gets a value that indicates whether the request entity body has been read, and if so, how it was read.
RequestContext	Gets the RequestContext instance of the current request.
RequestType	Gets or sets the HTTP data transfer method (`GET` or `POST`) used by the client.
ServerVariables	Gets a collection of Web server variables.
TimedOutToken	Gets a CancellationToken object that is tripped when a request times out.
TlsTokenBindingInfo	Gets the TLS token binding information. The property enables applications to retrieve token information from incoming HTTP requests for enhanced authentication.
TotalBytes	Gets the number of bytes in the current input stream.
Unvalidated	Gets the HTTP request values without triggering request validation.
Url	Gets information about the URL of the current request.
UrlReferrer	Gets information about the URL of the client's previous request that linked to the current URL.
UserAgent	Gets the raw user agent string of the client browser that has been provided. Please note it may be null.
UserHostAddress	Gets the IP host address of the remote client.
UserHostName	Gets the DNS name of the remote client.
UserLanguages	Gets a sorted string array of client language preferences.

Methods

Abort()	Forcibly terminates the underlying TCP connection, causing any outstanding I/O to fail. You might use this method in response to an attack by a malicious HTTP client.
BinaryRead(Int32)	Performs a binary read of a specified number of bytes from the current input stream.
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetBufferedInputStream()	Gets a Stream object that can be used to read the incoming HTTP entity body.
GetBufferlessInputStream()	Gets a Stream object that can be used to read the incoming HTTP entity body.
GetBufferlessInputStream(Boolean)	Gets a Stream object that can be used to read the incoming HTTP entity body, optionally disabling the request-length limit that is set in the MaxRequestLength property.
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetType()	Gets the Type of the current instance. (Inherited from Object)
InsertEntityBody()	Provides IIS with a copy of the HTTP request entity body.
InsertEntityBody(Byte[], Int32, Int32)	Provides IIS with a copy of the HTTP request entity body and with information about the request entity object.
MapImageCoordinates(String)	Maps an incoming image-field form parameter to appropriate x-coordinate and y-coordinate values.
MapPath(String)	Maps the specified virtual path to a physical path.
MapPath(String, String, Boolean)	Maps the specified virtual path to a physical path.
MapRawImageCoordinates(String)	Maps an incoming image field form parameter into appropriate x and y coordinate values.
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
SaveAs(String, Boolean)	Saves an HTTP request to disk.
ToString()	Returns a string that represents the current object. (Inherited from Object)
ValidateInput()	Causes validation to occur for the collections accessed through the Cookies, Form, and QueryString properties.

Applies to

Partajați prin