IAuthorizationPolicy.Evaluate(EvaluationContext, Object) 方法

定义

命名空间:

System.IdentityModel.Policy

程序集:

System.ServiceModel.Primitives.dll

包:

System.ServiceModel.Primitives v6.2.0

Source:

IAuthorizationPolicy.cs

评估用户是否符合此授权策略的需求。

public:
 bool Evaluate(System::IdentityModel::Policy::EvaluationContext ^ evaluationContext, System::Object ^ % state);

public bool Evaluate (System.IdentityModel.Policy.EvaluationContext evaluationContext, ref object state);

abstract member Evaluate : System.IdentityModel.Policy.EvaluationContext * obj -> bool

Public Function Evaluate (evaluationContext As EvaluationContext, ByRef state As Object) As Boolean

参数

evaluationContext

EvaluationContext

一个 EvaluationContext，其中包含授权策略所评估的声明集。

state

Object

一个 Object，由表示此授权策略的自定义状态的引用传递。

返回

Boolean

如果在其他授权策略向 evaluationContext 中添加其他声明时必须调用此授权策略的 Evaluate(EvaluationContext, Object) 方法，则为 false；否则为 true，表示此授权策略不需要任何其他评估。

示例

public bool Evaluate(EvaluationContext evaluationContext, ref object state)
{
    bool bRet = false;
    CustomAuthState customstate = null;

    // If state is null, then this method has not been called before, so
    // set up a custom state.
    if (state == null)
    {
        customstate = new CustomAuthState();
        state = customstate;
    }
    else
    {
        customstate = (CustomAuthState)state;
    }

    Console.WriteLine("Inside MyAuthorizationPolicy::Evaluate");

    // If claims have not been added yet...
    if (!customstate.ClaimsAdded)
    {
        // Create an empty list of Claims.
        IList<Claim> claims = new List<Claim>();

        // Iterate through each of the claim sets in the evaluation context.
        foreach (ClaimSet cs in evaluationContext.ClaimSets)
            // Look for Name claims in the current claim set.
            foreach (Claim c in cs.FindClaims(ClaimTypes.Name, Rights.PossessProperty))
                // Get the list of operations the given username is allowed to call.
                foreach (string s in GetAllowedOpList(c.Resource.ToString()))
                {
                    // Add claims to the list.
                    claims.Add(new Claim("http://example.org/claims/allowedoperation", s, Rights.PossessProperty));
                    Console.WriteLine("Claim added {0}", s);
                }

        // Add claims to the evaluation context.
        evaluationContext.AddClaimSet(this, new DefaultClaimSet(this.Issuer,claims));

        // Record that claims have been added.
        customstate.ClaimsAdded = true;

        // Return true, which indicates this need not be called again.
        bRet = true;
    }
    else
    {
        // This point should not be reached, but just in case...
        bRet = true;
    }

    return bRet;
}

Public Function Evaluate(ByVal evaluationContext As EvaluationContext, _
     ByRef state As Object) As Boolean Implements IAuthorizationPolicy.Evaluate

    Dim bRet As Boolean = False
    Dim customstate As CustomAuthState = Nothing

    ' If state is null, then this method has not been called before, so 
    ' set up a custom state.
    If state Is Nothing Then
        customstate = New CustomAuthState()
        state = customstate
    Else
        customstate = CType(state, CustomAuthState)
    End If
    Console.WriteLine("Inside MyAuthorizationPolicy::Evaluate")

    ' If the claims have not been added yet...
    If Not customstate.ClaimsAdded Then
        ' Create an empty list of Claims
        Dim claims As New List(Of Claim)

        ' Iterate through each of the claimsets in the evaluation context.
        Dim cs As ClaimSet
        For Each cs In evaluationContext.ClaimSets
            ' Look for Name claims in the current claim set.
            Dim c As Claim
            For Each c In cs.FindClaims(ClaimTypes.Name, Rights.PossessProperty)
                ' Get the list of operations the given username is allowed to call.
                Dim s As String
                For Each s In GetAllowedOpList(c.Resource.ToString())

                    ' Add claims to the list
                    claims.Add(New Claim("http://example.org/claims/allowedoperation", _
                                s, Rights.PossessProperty))
                    Console.WriteLine("Claim added {0}", s)
                Next s
            Next c
        Next cs 
        
        ' Add claims to the evaluation context.
        evaluationContext.AddClaimSet(Me, New DefaultClaimSet(Me.Issuer, claims))

        ' Record that claims have been added.
        customstate.ClaimsAdded = True

        ' Return true, which indicates the method need not to be called again.
        bRet = True
    Else
        ' Should never get here, but just in case...
        bRet = True
    End If


    Return bRet

End Function 'Evaluate

注解

注意

IAuthorizationPolicy 接口的实施者应当要求不同的线程多次调用 Evaluate 方法。

IAuthorizationPolicy 接口的实施者可使用 state 参数在对 Evaluate 方法的多次调用之间跟踪状态。 如果在对 Evaluate 方法的给定调用中设置了状态对象，则会在当前评估过程中向对 Evaluate 方法的每个后续调用传递同一对象实例。