HostSecurityManager.DetermineApplicationTrust Method

Determines whether an application should be executed.

Namespace: System.Security
Assembly: mscorlib (in mscorlib.dll)

public virtual ApplicationTrust DetermineApplicationTrust (
	Evidence applicationEvidence,
	Evidence activatorEvidence,
	TrustManagerContext context
public ApplicationTrust DetermineApplicationTrust (
	Evidence applicationEvidence, 
	Evidence activatorEvidence, 
	TrustManagerContext context
public function DetermineApplicationTrust (
	applicationEvidence : Evidence, 
	activatorEvidence : Evidence, 
	context : TrustManagerContext
) : ApplicationTrust
Not applicable.



The Evidence for the application to be activated.


Optionally, the Evidence for the activating application domain.


A TrustManagerContext that specifies the trust context.

Return Value

An ApplicationTrust object that contains trust information about the application.

Exception typeCondition


applicationEvidence is a null reference (Nothing in Visual Basic).


An ActivationArguments object could not be found in the application evidence.


The ActivationContext property in the activation arguments is a null reference (Nothing in Visual Basic).


The ApplicationTrust grant set does not contain the minimum request set specified by the ActivationContext.

This method can be overridden by a derived class. The base implementation calls the application security manager to determine if the application should be executed.

The base implementation does not use the activator evidence. However, an overridden implementation could use the activator evidence to determine the security evidence for the application domain attempting to activate the application.

The following code example shows an override of the DetermineApplicationTrust method for a custom host security manager. This example is part of a larger example provided for the HostSecurityManager class.

[SecurityPermissionAttribute(SecurityAction.Demand, Execution = true)]
[SecurityPermissionAttribute(SecurityAction.Assert, Unrestricted = true)]
public override ApplicationTrust DetermineApplicationTrust(Evidence applicationEvidence, Evidence activatorEvidence, TrustManagerContext context)
    if (applicationEvidence == null)
        throw new ArgumentNullException("applicationEvidence");

    // Get the activation context from the application evidence.
    // This HostSecurityManager does not examine the activator evidence
    // nor is it concerned with the TrustManagerContext;
    // it simply grants the requested grant in the application manifest.

    IEnumerator enumerator = applicationEvidence.GetHostEnumerator();
    ActivationArguments activationArgs = null;
    while (enumerator.MoveNext())
        activationArgs = enumerator.Current as ActivationArguments;
        if (activationArgs != null)

    if (activationArgs == null)
        return null;

    ActivationContext activationContext = activationArgs.ActivationContext;
    if (activationContext == null)
        return null;

    ApplicationTrust trust = new ApplicationTrust(activationContext.Identity);
    ApplicationSecurityInfo asi = new ApplicationSecurityInfo(activationContext);
    trust.DefaultGrantSet = new PolicyStatement(asi.DefaultRequestSet, PolicyStatementAttribute.Nothing);
    trust.IsApplicationTrustedToRun = true;
    return trust;

Windows 98, Windows Server 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0