PnrpPermission.IsSubsetOf(IPermission) Method

Definition

Determines whether the current PnrpPermission is a subset of the specified permission.

public:
 override bool IsSubsetOf(System::Security::IPermission ^ target);
public override bool IsSubsetOf (System.Security.IPermission target);
override this.IsSubsetOf : System.Security.IPermission -> bool
Public Overrides Function IsSubsetOf (target As IPermission) As Boolean

Parameters

target
IPermission

A permission that is to be tested for the subset relationship. This permission must be of the same type as the current permission.

Returns

Boolean

true if the current PnrpPermission is a subset of the specified permission; otherwise, false.

Exceptions

The target parameter is not a null reference (Nothing in Visual Basic) and is not an instance of the same class as the current permission.

Remarks

The current PnrpPermission is a subset of the specified permission if the current permission specifies a set of operations that is wholly contained by the specified permission. For example, a permission that represents access to "C:\example.txt" is a subset of a permission that represents access to "C:\". If this method returns true, the current permission represents no more access to the protected resource than does the specified permission.

The following statements are required to be true for all implementations of the IsSubsetOf method. X, Y, and Z represent IPermission objects that are not a null reference (Nothing in Visual Basic).

  • X.IsSubsetOf(X) returns true.

  • X.IsSubsetOf(Y) returns the same value as Y.IsSubsetOf(X) if and only if X and Y represent the same set of permissions.

  • If X.IsSubsetOf(Y) and Y.IsSubsetOf(Z) both return true, X.IsSubsetOf(Z) returns true.

If X represents an empty IPermission object with a permission state of None, and Y represents an IPermission object that is a null reference (Nothing in Visual Basic), X.IsSubsetOf(Y) returns true. If Z is also an empty permission, the compound set operation X.Union(Z).IsSubsetOf(Y) also returns true because the Union of two empty permissions is an empty permission.

Applies to

See also