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WebPermission Class

Controls rights to access HTTP Internet resources.

Namespace:  System.Net
Assembly:  System (in System.dll)

[SerializableAttribute]
public sealed class WebPermission : CodeAccessPermission, 
	IUnrestrictedPermission

The WebPermission type exposes the following members.

  NameDescription
Public methodWebPermission()Creates a new instance of the WebPermission class.
Public methodWebPermission(PermissionState)Creates a new instance of the WebPermission class that passes all demands or fails all demands.
Public methodWebPermission(NetworkAccess, String)Initializes a new instance of the WebPermission class with the specified access rights for the specified URI.
Public methodWebPermission(NetworkAccess, Regex)Initializes a new instance of the WebPermission class with the specified access rights for the specified URI regular expression.
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  NameDescription
Public propertyAcceptListThis property returns an enumeration of a single accept permissions held by this WebPermission. The possible objects types contained in the returned enumeration are String and System.Text.RegularExpressions.Regex.
Public propertyConnectListThis property returns an enumeration of a single connect permissions held by this WebPermission. The possible objects types contained in the returned enumeration are String and System.Text.RegularExpressions.Regex.
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  NameDescription
Public methodAddPermission(NetworkAccess, String)Adds the specified URI string with the specified access rights to the current WebPermission.
Public methodAddPermission(NetworkAccess, Regex)Adds the specified URI with the specified access rights to the current WebPermission.
Public methodAssertDeclares that the calling code can access the resource protected by a permission demand through the code that calls this method, even if callers higher in the stack have not been granted permission to access the resource. Using Assert can create security issues. (Inherited from CodeAccessPermission.)
Public methodCopyCreates a copy of a WebPermission. (Overrides CodeAccessPermission.Copy().)
Public methodDemandForces a SecurityException at run time if all callers higher in the call stack have not been granted the permission specified by the current instance. (Inherited from CodeAccessPermission.)
Public methodDeny Obsolete. Prevents callers higher in the call stack from using the code that calls this method to access the resource specified by the current instance. (Inherited from CodeAccessPermission.)
Public methodEqualsDetermines whether the specified CodeAccessPermission object is equal to the current CodeAccessPermission. (Inherited from CodeAccessPermission.)
Public methodFromXmlReconstructs a WebPermission from an XML encoding. (Overrides CodeAccessPermission.FromXml(SecurityElement).)
Public methodGetHashCodeGets a hash code for the CodeAccessPermission object that is suitable for use in hashing algorithms and data structures such as a hash table. (Inherited from CodeAccessPermission.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodIntersectReturns the logical intersection of two WebPermission instances. (Overrides CodeAccessPermission.Intersect(IPermission).)
Public methodIsSubsetOfDetermines whether the current WebPermission is a subset of the specified object. (Overrides CodeAccessPermission.IsSubsetOf(IPermission).)
Public methodIsUnrestrictedChecks the overall permission state of the WebPermission.
Public methodPermitOnlyPrevents callers higher in the call stack from using the code that calls this method to access all resources except for the resource specified by the current instance. (Inherited from CodeAccessPermission.)
Public methodToStringCreates and returns a string representation of the current permission object. (Inherited from CodeAccessPermission.)
Public methodToXmlCreates an XML encoding of a WebPermission and its current state. (Overrides CodeAccessPermission.ToXml().)
Public methodUnionReturns the logical union between two instances of the WebPermission class. (Overrides CodeAccessPermission.Union(IPermission).)
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WebPermission provides a set of methods and properties to control access to Internet resources. You can use a WebPermission to provide either restricted or unrestricted access to your resource, based on the PermissionState that is set when the WebPermission is created.

Create a WebPermission instance by calling its constructor using one of the following sets of parameters:

The ConnectList and AcceptList hold the URIs to which you have granted access permission. To add a URI to either of these lists, use AddPermission. If you pass Accept as the NetworkAccess parameter, the URI will be added to the AcceptList. WebPermission will allow connections to your target class with URIs matching the AcceptList.

Caution noteCaution

To deny access to an Internet resource, you must deny access to all the possible paths to that resource. This requires calling WebPermission.WebPermission with state parameter set to Deny. A better approach is to allow access to the specific resource only. For more information about this subject, refer to the Using the Deny Method topic.

NoteNote

You need to deny access using only the resource canonical path. There is no need to use all the path's syntactical variations.

NoteNote

User name and default port information is stripped from the Uri before the comparison with the regular expression argument that is supplied to the WebPermission(NetworkAccess, Regex) constructor. If the regular expression contains user information or the default port number, then all incoming Uris will fail to match the regular expression.

The following example demonstrates how to create a new instance of WebPermission using a Regex. Additional hosts are added to the connect and accept list of WebPermission. Finally, the connect and accept list are displayed to the console.


    //  Create a Regex that accepts all URLs containing the host fragment www.contoso.com.
    Regex myRegex = new Regex(@"http://www\.contoso\.com/.*");

    // Create a WebPermission that gives permissions to all the hosts containing the same host fragment.
    WebPermission myWebPermission = new WebPermission(NetworkAccess.Connect,myRegex);

    //Add connect privileges for a www.adventure-works.com.
    myWebPermission.AddPermission(NetworkAccess.Connect,"http://www.adventure-works.com");

    //Add accept privileges for www.alpineskihouse.com.
    myWebPermission.AddPermission(NetworkAccess.Accept, "http://www.alpineskihouse.com/");

    // Check whether all callers higher in the call stack have been granted the permission.
    myWebPermission.Demand();

    // Get all the URIs with Connect permission.
    IEnumerator myConnectEnum = myWebPermission.ConnectList;
    Console.WriteLine("\nThe 'URIs' with 'Connect' permission are :\n");
    while (myConnectEnum.MoveNext())
    {Console.WriteLine("\t" + myConnectEnum.Current);}

    // Get all the URIs with Accept permission.	  
    IEnumerator myAcceptEnum = myWebPermission.AcceptList;
    Console.WriteLine("\n\nThe 'URIs' with 'Accept' permission is :\n");

    while (myAcceptEnum.MoveNext())
      {Console.WriteLine("\t" + myAcceptEnum.Current);}

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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