System.Security.SecurityState Class

Provides a base class for requesting the security status of an action from the AppDomainManager object.

See Also: SecurityState Members

Syntax

public abstract class SecurityState

Remarks

You must inherit from this class to provide a class that includes a property that specifies the security-sensitive action to be performed. The System.Security.SecurityState object that is instantiated from the derived class is passed to the AppDomainManager.CheckSecuritySettings(SecurityState) method to determine whether the host allows that action to be performed. The default implementation of the AppDomainManager.CheckSecuritySettings(SecurityState) method always returns false. The method must be overridden to detect the actions that are allowed.

For example, if you want to access a Web camera in your library code, you would create a WebcamSecurityState object and call the SecurityState.EnsureState method to determine whether the host allows Web camera access, as shown in the following example. (You can find the code for WebcamSecurityState in the "Example" section.)

Example

WebcamSecurityState securityState = new WebcamSecurityState("Safe access to Webcam", WebcamSecurityOptions.SafeAccess);
try
{
   securityState.EnsureState();
   // Allocate memory.
   }
catch (ApplicationException e)
{
    // Handle any exception that is thrown.
    System.Diagnostics.Debug.WriteLine(e.Message);
}

To process the call the AppDomainManager must be made aware of WebcamSecurityState through an override of the AppDomainManager.CheckSecuritySettings(SecurityState) method, as shown in the following example.

Example

[SecurityCritical]
public override bool CheckSecuritySettings(System.Security.SecurityState securityState)
{
   switch (securityState.ToString())
   {
      case "WebcamSecurityState":
      {
          if ((securityState as WebcamSecurityState).Options == WebcamSecurityOptions.SafeAccess)
              return PromptUser((securityState as WebcamSecurityState).Description);
           return false;
      }
   }
      return false;
}
private bool PromptUser(string text)
{
   // Replace the OpenFileDialog with a custom user prompt.
   OpenFileDialog o = new OpenFileDialog();
   o.Title = text;
   if (o.ShowDialog() == DialogResult.OK)
      return true;
   else
      return false;
}

Requirements

Namespace: System.Security
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 2.0.0.0, 4.0.0.0