System.Security.Policy.FileCodeGroup Class

Summary

Grants permission to manipulate files located in the code assemblies to code assemblies that match the membership condition. This class cannot be inherited.

C# Syntax:

[Serializable] public sealed class FileCodeGroup : CodeGroup

Code groups are the building blocks of code access security policy. Each policy level consists of a root code group that can have child code groups. Each child code group can have their own child code groups; this behavior extends to any number of levels, forming a tree. Each code group has a membership condition that determines if a given assembly belongs to it based on the evidence for that assembly. Only code groups whose membership conditions match a given assembly and their child code groups apply policy.

FileCodeGroup has the same child matching semantics as UnionCodeGroup. However, FileCodeGroup returns a permission set containing a dynamically-calculated FileIOPermission that grants file access to the directory from which the code is run; UnionCodeGroup only returns a static permission set. The type of file access granted is passed as a parameter to the constructor.

This code group only matches assemblies run over a file protocol, that is, assemblies that have URLs that point to a file or UNC path.

System.Security.Policy Namespace See also:
MSDN: codegroups

System.Security.Policy.FileCodeGroup Member List:

Public Constructors

ctor #1

Initializes a new instance of the FileCodeGroup class.

Public Properties

AttributeString	Read-only Overridden: Gets a string representation of the attributes of the policy statement for the code group.
Children (inherited from System.Security.Policy.CodeGroup)	Read-write See base class member description: System.Security.Policy.CodeGroup.Children Gets or sets an ordered list of the child code groups of a code group.
Description (inherited from System.Security.Policy.CodeGroup)	Read-write See base class member description: System.Security.Policy.CodeGroup.Description Gets or sets the description of the code group.
MembershipCondition (inherited from System.Security.Policy.CodeGroup)	Read-write See base class member description: System.Security.Policy.CodeGroup.MembershipCondition Gets or sets the code group's membership condition.
MergeLogic	Read-only Overridden: Gets the merge logic.
Name (inherited from System.Security.Policy.CodeGroup)	Read-write See base class member description: System.Security.Policy.CodeGroup.Name Gets or sets the name of the code group.
PermissionSetName	Read-only Overridden: Gets the name of the named permission set for the code group.
PolicyStatement (inherited from System.Security.Policy.CodeGroup)	Read-write See base class member description: System.Security.Policy.CodeGroup.PolicyStatement Gets or sets the policy statement associated with the code group.

Public Methods

AddChild (inherited from System.Security.Policy.CodeGroup)	See base class member description: System.Security.Policy.CodeGroup.AddChild Adds a child code group to the current code group.
Copy	Overridden: Makes a deep copy of the current code group.
Equals	Overloaded: Equals(object o) Overridden: Determines whether the specified code group is equivalent to the current code group.
Equals (inherited from System.Security.Policy.CodeGroup)	Overloaded: Equals(CodeGroup cg, bool compareChildren) See base class member description: System.Security.Policy.CodeGroup.Equals Determines whether the specified code group is equivalent to the current code group, checking the child code groups as well, if specified.
FromXml (inherited from System.Security.Policy.CodeGroup)	Overloaded: FromXml(SecurityElement e) See base class member description: System.Security.Policy.CodeGroup.FromXml Reconstructs a security object with a given state from an XML encoding.
FromXml (inherited from System.Security.Policy.CodeGroup)	Overloaded: FromXml(SecurityElement e, PolicyLevel level) See base class member description: System.Security.Policy.CodeGroup.FromXml Reconstructs a security object with a given state and policy level from an XML encoding.
GetHashCode	Overridden: Gets the hash code of the current code group.
GetType (inherited from System.Object)	See base class member description: System.Object.GetType Derived from System.Object, the primary base class for all objects.
RemoveChild (inherited from System.Security.Policy.CodeGroup)	See base class member description: System.Security.Policy.CodeGroup.RemoveChild Removes the specified child code group.
Resolve	Overridden: Resolves policy for the code group and its descendants for a set of evidence.
ResolveMatchingCodeGroups	Overridden: Resolves matching code groups.
ToString (inherited from System.Object)	See base class member description: System.Object.ToString Derived from System.Object, the primary base class for all objects.
ToXml (inherited from System.Security.Policy.CodeGroup)	Overloaded: ToXml() See base class member description: System.Security.Policy.CodeGroup.ToXml Creates an XML encoding of the security object and its current state.
ToXml (inherited from System.Security.Policy.CodeGroup)	Overloaded: ToXml(PolicyLevel level) See base class member description: System.Security.Policy.CodeGroup.ToXml Creates an XML encoding of the security object, its current state, and the policy level within which the code exists.

Protected Methods

CreateXml	Overridden: Creates an XML encoding of the security object, its current state, and the policy level within which the code exists.
Finalize (inherited from System.Object)	See base class member description: System.Object.Finalize Derived from System.Object, the primary base class for all objects.
MemberwiseClone (inherited from System.Object)	See base class member description: System.Object.MemberwiseClone Derived from System.Object, the primary base class for all objects.
ParseXml	Overridden: Reconstructs a security object with a given state and policy level from an XML encoding.

Hierarchy:

• System.Object
• System.Security.Policy.CodeGroup
• System.Security.Policy.FileCodeGroup

System.Security.Policy.FileCodeGroup Member Details

Summary

Initializes a new instance of the FileCodeGroup class.

C# Syntax:

public FileCodeGroup(    IMembershipCondition membershipCondition,    FileIOPermissionAccess access );

membershipCondition

A membership condition that tests evidence to determine whether this code group applies policy.

access

One of the FileIOPermissionAccess values. This value is used to construct the FileIOPermission that is granted.

Exceptions

Exception Type	Condition
ArgumentNullException	The membershipCondition parameter is null.
ArgumentException	The type of the membershipCondition parameter is not valid. -or- The type of the access parameter is not valid.

This constructor creates a basic code group. Child code groups can be added with the CodeGroup.AddChild method.

FileCodeGroup returns a permission set containing a dynamically-calculated FileIOPermission that grants file access to the directory from which the code is run. The type of access granted is determined by the access parameter.

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Summary

Gets a string representation of the attributes of the policy statement for the code group.

C# Syntax:

public override string AttributeString {get;}

FileCodeGroup does not use FileCodeGroup.AttributeString, so this property is always null.

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Inherited
See base class member description: System.Security.Policy.CodeGroup.Children

Summary

Gets or sets an ordered list of the child code groups of a code group.

C# Syntax:

public IList Children {get; set;}

Exceptions

Exception Type	Condition
ArgumentException	An attempt is made to set this property to null.

The order of child code groups is significant for certain code groups.

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Inherited
See base class member description: System.Security.Policy.CodeGroup.Description

Summary

Gets or sets the description of the code group.

C# Syntax:

public string Description {get; set;}

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Inherited
See base class member description: System.Security.Policy.CodeGroup.MembershipCondition

Summary

Gets or sets the code group's membership condition.

C# Syntax:

public IMembershipCondition MembershipCondition {get; set;}

Exceptions

Exception Type	Condition
ArgumentException	An attempt is made to set this parameter to null.

A membership condition tests evidence and returns a Boolean value that tells whether there is a match.

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Summary

Gets the merge logic.

C# Syntax:

public override string MergeLogic {get;}

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Inherited
See base class member description: System.Security.Policy.CodeGroup.Name

Summary

Gets or sets the name of the code group.

C# Syntax:

public string Name {get; set;}

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Summary

Gets the name of the named permission set for the code group.

C# Syntax:

public override string PermissionSetName {get;}

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Inherited
See base class member description: System.Security.Policy.CodeGroup.PolicyStatement

Summary

Gets or sets the policy statement associated with the code group.

C# Syntax:

public PolicyStatement PolicyStatement {get; set;}

The policy statement applies to code in assemblies when evidence matches the membership condition.

This property can also be set by passing a policy statement to the constructor.

The following example sets the PolicyStatement for a code group.

        codeGroup.PolicyStatement = new PolicyStatement(new NamedPermissionSet("MyPermissionSet"));

    

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Inherited
See base class member description: System.Security.Policy.CodeGroup.AddChild

Summary

Adds a child code group to the current code group.

C# Syntax:

public void AddChild(    CodeGroup group );

group

The code group to be added as a child. This new child code group is added to the end of the list.

Exceptions

Exception Type	Condition
ArgumentNullException	The group parameter is null.
ArgumentException	The group parameter is not a valid code group.

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Summary

Makes a deep copy of the current code group.

C# Syntax:

public override CodeGroup Copy();

Return Value:

An equivalent copy of the current code group, including its membership conditions and child code groups.

This method makes a deep copy of the code group, so that copies of all objects the code group contains are also made.

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Summary

Creates an XML encoding of the security object, its current state, and the policy level within which the code exists.

C# Syntax:

protected override void CreateXml(    SecurityElement element,    PolicyLevel level );

element

The XML encoding to use to create the security object.

level

The policy level within which the code group exists.

This method is for use by the security system, and is not typically called by application code.

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Summary

Determines whether the specified code group is equivalent to the current code group.

C# Syntax:

public override bool Equals(    object o );

o

The code group to compare with the current code group.

Return Value:

true if the specified code group is equivalent to the current code group; otherwise, false.

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Inherited
See base class member description: System.Security.Policy.CodeGroup.Equals

Summary

Determines whether the specified code group is equivalent to the current code group, checking the child code groups as well, if specified.

C# Syntax:

public bool Equals(    CodeGroup cg,    bool compareChildren );

cg

The code group to compare with the current code group.

compareChildren

true to compare child code groups, as well; otherwise, false.

Return Value:

true if the specified code group is equivalent to the current code group; otherwise, false.

Two code groups are equivalent if they have the same CodeGroup.Name, CodeGroup.Description, and CodeGroup.MembershipCondition.

If the compareChildren parameter is true, this method will only return true if the current code group and all its child code groups are equivalent to the specified code group and all its child code groups.

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Inherited
See base class member description: System.Object.Finalize

C# Syntax:

~FileCodeGroup();

For more information on members inherited from System.Object click on the link above.

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Inherited
See base class member description: System.Security.Policy.CodeGroup.FromXml

Summary

Reconstructs a security object with a given state from an XML encoding.

C# Syntax:

public void FromXml(    SecurityElement e );

e

The XML encoding to use to reconstruct the security object.

Exceptions

Exception Type	Condition
ArgumentNullException	The e parameter is null.

Notes to inheritors: CodeGroup.FromXml and CodeGroup.ToXml cannot be overridden. If you need to change the way in which your code group implementation handles XML, override the CodeGroup.ParseXml and CodeGroup.CreateXml methods.

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Inherited
See base class member description: System.Security.Policy.CodeGroup.FromXml

Summary

Reconstructs a security object with a given state and policy level from an XML encoding.

C# Syntax:

public void FromXml(    SecurityElement e,    PolicyLevel level );

e

The XML encoding to use to reconstruct the security object.

level

The policy level within which the code group exists.

Exceptions

Exception Type	Condition
ArgumentNullException	The e parameter is null.

The policy level context is provided for resolution of named permission sets.

Notes to inheritors: CodeGroup.FromXml and CodeGroup.ToXml cannot be overridden. If you need to change the way in which your code group implementation handles XML, override the CodeGroup.ParseXml and CodeGroup.CreateXml methods.

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Summary

Gets the hash code of the current code group.

C# Syntax:

public override int GetHashCode();

Return Value:

The hash code of the current code group.

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Inherited
See base class member description: System.Object.GetType

C# Syntax:

public Type GetType();

For more information on members inherited from System.Object click on the link above.

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Inherited
See base class member description: System.Object.MemberwiseClone

C# Syntax:

protected object MemberwiseClone();

For more information on members inherited from System.Object click on the link above.

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Summary

Reconstructs a security object with a given state and policy level from an XML encoding.

C# Syntax:

protected override void ParseXml(    SecurityElement e,    PolicyLevel level );

e

The XML encoding to use to reconstruct the security object.

level

The policy level within which the code group exists.

This method is for use by the security system, and is not typically called by application code.

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Inherited
See base class member description: System.Security.Policy.CodeGroup.RemoveChild

Summary

Removes the specified child code group.

C# Syntax:

public void RemoveChild(    CodeGroup group );

group

The code group to be removed as a child.

Exceptions

Exception Type	Condition
ArgumentException	The group parameter is not an immediate child code group of the current code group.

Only immediate child code groups can be removed with this method.

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Summary

Resolves policy for the code group and its descendants for a set of evidence.

C# Syntax:

public override PolicyStatement Resolve(    Evidence evidence );

evidence

The evidence for the assembly.

Return Value:

A policy statement consisting of the permissions granted by the code group with optional attributes, or null if the code group does not apply (the membership condition does not match the specified evidence).

Exceptions

Exception Type	Condition
ArgumentNullException	The evidence parameter is null.
PolicyException	The current policy is null. -or- More than one code group (including the parent code group and all child code groups) is marked PolicyStatementAttribute.Exclusive.

Given evidence for an assembly to be loaded, this method evaluates the code group by first checking the membership condition against the specified evidence. If there is a match, this method returns a policy statement for the code group, including evaluation of child code groups.

The .NET Framework security system uses FileCodeGroup.Resolve on the policy levels to determine which permissions to grant to loaded code from the resulting policy statements and the code request on the assembly.

FileCodeGroup uses union semantics and forms a permission set based on the Url specified by evidence.

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Summary

Resolves matching code groups.

C# Syntax:

public override CodeGroup ResolveMatchingCodeGroups(    Evidence evidence );

evidence

The evidence for the assembly.

Return Value:

A CodeGroup that is the root of the tree of matching code groups.

Exceptions

Exception Type	Condition
ArgumentNullException	The evidence parameter is null.

Given evidence for an assembly to be loaded, this method evaluates the code group by first checking the membership condition against the specified evidence. If there is a match, this method returns a root code group. The code group that is returned contains child code groups, which in turn can have child code groups as necessary to reflect the complete set of code groups that were matched by the evidence provided.

FileCodeGroup uses union semantics and forms a permission set based on the Url specified by evidence.

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Inherited
See base class member description: System.Object.ToString

C# Syntax:

public virtual string ToString();

For more information on members inherited from System.Object click on the link above.

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Inherited
See base class member description: System.Security.Policy.CodeGroup.ToXml

Summary

Creates an XML encoding of the security object and its current state.

C# Syntax:

public SecurityElement ToXml();

Return Value:

An XML encoding of the security object, including any state information.

Notes to inheritors: CodeGroup.FromXml and CodeGroup.ToXml cannot be overridden. If you need to change the way in which your code group implementation handles XML, override the CodeGroup.ParseXml and CodeGroup.CreateXml methods.

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Inherited
See base class member description: System.Security.Policy.CodeGroup.ToXml

Summary

Creates an XML encoding of the security object, its current state, and the policy level within which the code exists.

C# Syntax:

public SecurityElement ToXml(    PolicyLevel level );

level

The policy level within which the code group exists.

Return Value:

An XML encoding of the security object, including any state information.

The policy level context is provided for resolution of named permission sets.

Notes to inheritors: CodeGroup.FromXml and CodeGroup.ToXml cannot be overridden. If you need to change the way in which your code group implementation handles XML, override the CodeGroup.ParseXml and CodeGroup.CreateXml methods.

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