HttpRequest Class
Enables ASP.NET to read the HTTP values sent by a client during a Web request.
Assembly: System.Web (in System.Web.dll)
| Name | Description | |
|---|---|---|
![]() | HttpRequest(String, String, String) | This API supports the product infrastructure and is not intended to be used directly from your code. Initializes an HttpRequest object. |
| Name | Description | |
|---|---|---|
![]() | 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. |
![]() | 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. |
| Name | Description | |
|---|---|---|
![]() | 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() | |
![]() | 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() | |
![]() | 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. |
![]() | 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. |
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. |
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 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.
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.
Security Note
|
|---|
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="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 ' 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)) ' 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 ' 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 ' 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)) ' 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 ' 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)) ' 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 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>
Available since 1.1
Any public static ( Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.



