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LambdaValue<TResult> Class

Represents a lambda expression used as an r-value, which supports binding of In arguments.

System.Object
  System.Activities.Activity
    System.Activities.ActivityWithResult
      System.Activities.Activity<TResult>
        System.Activities.CodeActivity<TResult>
          System.Activities.Expressions.LambdaValue<TResult>

Namespace:  System.Activities.Expressions
Assembly:  System.Activities (in System.Activities.dll)

public sealed class LambdaValue<TResult> : CodeActivity<TResult>, 
	IValueSerializableExpression

Type Parameters

TResult

The type of value returned by the expression.

The LambdaValue<TResult> type exposes the following members.

  NameDescription
Public methodLambdaValue<TResult>Initializes a new instance of the LambdaValue<TResult> class using the specified expression.
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  NameDescription
Protected propertyCacheIdGets the identifier of the cache that is unique within the scope of the workflow definition. (Inherited from Activity.)
Protected propertyConstraintsGets a collection of Constraint activities that can be configured to provide validation for the Activity. (Inherited from Activity.)
Public propertyDisplayNameGets or sets an optional friendly name that is used for debugging, validation, exception handling, and tracking. (Inherited from Activity.)
Public propertyIdGets an identifier that is unique in the scope of the workflow definition. (Inherited from Activity.)
Protected propertyImplementationNot supported. (Inherited from CodeActivity<TResult>.)
Public propertyResultGets or sets the result argument for the Activity<TResult>. (Inherited from Activity<TResult>.)
Public propertyResultTypeWhen implemented in a derived class, gets the type of an activity OutArgument. (Inherited from ActivityWithResult.)
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  NameDescription
Protected methodCacheMetadata(ActivityMetadata)Not implemented. Use CacheMetadata(CodeActivityMetadata) instead. (Inherited from CodeActivity<TResult>.)
Protected methodCacheMetadata(CodeActivityMetadata)Creates and validates a description of the activity’s arguments, variables, child activities, and activity delegates. (Inherited from CodeActivity<TResult>.)
Public methodCanConvertToStringThis method always returns true and is used in conjunction with ConvertToString(IValueSerializerContext) to provide descriptive error messages when an attempt is made to serialize this activity to XAML.
Public methodConvertToStringThrows a LambdaSerializationException, and is used in conjunction with CanConvertToString(IValueSerializerContext) to provide descriptive error messages when an attempt is made to serialize this activity to XAML.
Public methodEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodExecuteWhen implemented in a derived class, performs the execution of the activity. (Inherited from CodeActivity<TResult>.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodShouldSerializeDisplayNameIndicates whether the DisplayName property should be serialized. (Inherited from Activity.)
Public methodToStringReturns a String that contains the Id and DisplayName of the Activity. (Inherited from Activity.)
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LambdaValue<TResult> is used for lambda expressions specified in code and cannot be serialized to XAML. If an attempt to serialize a workflow that contains a LambdaValue<TResult> is made, a LambdaSerializationException is thrown. If the containing workflow requires XAML serialization, use VisualBasicValue<TResult> or use ExpressionServices to convert the LambdaValue<TResult> to a format that can be serialized.

This activity uses the LINQ to Entity provider to evaluate LINQ expressions. Any LINQ expressions used with this activity must be evaluatable by the ADO.Net Entity Data Model. For example, LINQ expressions cannot be used to reference activities, variables, or arguments of the workflow itself.

.NET Framework

Supported in: 4

.NET Framework Client Profile

Supported in: 4

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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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