System.Net.WebPermission Class

public class WebPermission : CodeAccessPermission

Base Types

Object
  CodeAccessPermission
    WebPermission

This type implements IPermission.

Assembly

System

Library

Networking

Summary

Controls access to Internet resources.

Description

The XML encoding of a WebPermission instance is defined below in EBNF format. The following conventions are used:

• All non-literals in the grammar below are shown in normal type.

• All literals are in bold font.

The following meta-language symbols are used:

• '*' represents a meta-language symbol suffixing an expression that can appear zero or more times.
• '?' represents a meta-language symbol suffixing an expression that can appear zero or one time.
• '+' represents a meta-language symbol suffixing an expression that can appear one or more times.
• '(',')' is used to group literals, non-literals or a mixture of literals and non-literals.
• '|' denotes an exclusive disjunction between two expressions.
• '::= ' denotes a production rule where a left hand non-literal is replaced by a right hand expression containing literals, non-literals or both.

BuildVersion refers to the build version of the shipping CLI. This is a dotted build number such as '2412.0'.

ECMAPubKeyToken ::= b77a5c561934e089

HostName refers to a host name such as www.contoso.com .

Portnumber denotes a Int32 value indicating a port.

TransportProtocol ::= 1 | 2 | 3 /*1= UDP , 2 = TCP, 3 = both */

WebPermissionXML ::=

<IPermission

class="

System.Net.WebPermission,

System,

Version=1.0. BuildVersion,

Culture=neutral,

PublicKeyToken= ECMAPubKeyToken"

version="1"

(

Unrestricted="true"/>

)

|

>

(<ConnectAccess>

(

<URI> HostName# PortNumber# TransportProtocol</URI>

)+

</ConnectAccess>

</IPermission>

)

|

>

(<AcceptAccess>

(

<URI> HostName# PortNumber# TransportProtocol</URI>

)+

</AcceptAccess>

</IPermission>

)

|

/>

See Also

System.Net Namespace

Members

WebPermission Constructors

WebPermission(System.Security.Permissions.PermissionState) Constructor
WebPermission(System.Net.NetworkAccess, System.String) Constructor

WebPermission Methods

WebPermission.Copy Method
WebPermission.FromXml Method
WebPermission.Intersect Method
WebPermission.IsSubsetOf Method
WebPermission.ToXml Method
WebPermission.Union Method

Constructs and initializes a new instance of the WebPermission class with the specified PermissionState value.

Parameters

state

A PermissionState value.

Description

[Note: This constructor creates either fully restricted (System.Security.Permissions.PermissionState.None) or System.Security.Permissions.PermissionState.Unrestricted access to Internet resources.

]

See Also

System.Net.WebPermission Class, System.Net Namespace

Constructs and initializes a new instance of the WebPermission class that secures access to the specified URI.

Parameters

access

A NetworkAccess value indicating the type of access to secure.

uriString

A String that represents the URI to grant access rights to. [Note: For more information on the format of this string, see Uri.]

Exceptions

Exception Type	Condition
ArgumentNullException	uriString is null .

See Also

System.Net.WebPermission Class, System.Net Namespace

Returns a new WebPermission object containing the same values as the current instance.

Return Value

A new WebPermission instance containing the same values as the current instance.

Description

[Note: The object returned by this method represents the same access to resources as the current instance.

This method overrides System.Security.CodeAccessPermission.Copy and is implemented to support the IPermission interface.

]

See Also

System.Net.WebPermission Class, System.Net Namespace

Reconstructs the state of a WebPermission object using the specified XML encoding.

Parameters

securityElement

A SecurityElement instance containing the XML encoding to use to reconstruct the state of a WebPermission object.

Exceptions

Exception Type	Condition
ArgumentNullException	securityElement is null .
ArgumentException	securityElement does not contain the encoding for a WebPermission instance.

Description

The state of the current instance is changed to the state encoded in securityElement.

[Note: For the XML encoding for this class, see the WebPermission class page.

This method overrides System.Security.CodeAccessPermission.FromXml(System.Security.SecurityElement) .

]

See Also

System.Net.WebPermission Class, System.Net Namespace

Returns a new WebPermission object that is the intersection of the current instance and the specified object.

Parameters

target

A WebPermission instance to intersect with the current instance.

Return Value

A new WebPermission instance that represents the intersection of the current instance and target. If the intersection is empty, returns null . If the current instance is unrestricted, returns a copy of target. If target is unrestricted, returns a copy of the current instance.

Exceptions

Exception Type	Condition
ArgumentNullException	target is null .
ArgumentException	target is not null and is not of type WebPermission .

Description

[Note: The intersection of two permissions is a permission that secures the resources and operations secured by both permissions. Specifically, it represents the minimum permission such that any demand that passes both permissions will also pass their intersection.

This method overrides System.Security.CodeAccessPermission.Intersect(System.Security.IPermission) and is implemented to support the IPermission interface.

]

See Also

System.Net.WebPermission Class, System.Net Namespace

target

A WebPermission instance that is to be tested for the subset relationship.

Return Value

true if the current instance is a subset of target ; otherwise, false . If target is null, return false . If the current instance is unrestricted, and target is not, returns false . If target is unrestricted, returns true .

Exceptions

Exception Type	Condition
ArgumentException	target is not of type WebPermission.

Description

[Note: The current instance is a subset of target if the current instance specifies a set of accesses to resources that is wholly contained by target. For example, a permission that represents read access to a file is a subset of a permission that represents read and write access to the file.

If this method returns true , the current instance describes access to internet resources that is also described by target .

This method overrides System.Security.CodeAccessPermission.IsSubsetOf(System.Security.IPermission) and is implemented to support the IPermission interface.

]

See Also

System.Net.WebPermission Class, System.Net Namespace

A SecurityElement containing the XML encoding of the state of the current instance.

Description

[Note: For the XML encoding for this class, see the WebPermission class page.

This method overrides System.Security.CodeAccessPermission.ToXml .

]

See Also

System.Net.WebPermission Class, System.Net Namespace

Returns a new WebPermission object that is the union of the current instance and the specified object.

Parameters

target

The WebPermission instance to combine with the current instance.

Return Value

A new WebPermission instance that represents the union of the current instance and target. If the current instance or target is unrestricted, returns a WebPermission instance that is unrestricted.

Exceptions

Exception Type	Condition
ArgumentException	target is not null and is not of type WebPermission .

Description

[Note: The result of a call to System.Net.WebPermission.Union(System.Security.IPermission) is a permission that represents all of the access to permissions represented by the current instance as well as the permissions represented by target. Any demand that passes either the current instance or target passes their union.

This method overrides System.Security.CodeAccessPermission.Union(System.Security.IPermission) and is implemented to support the IPermission interface.

]

See Also

System.Net.WebPermission Class, System.Net Namespace