LambdaValue<TResult> LambdaValue<TResult> LambdaValue<TResult> LambdaValue<TResult> Class

Definition

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

generic <typename TResult>
public ref class LambdaValue sealed : System::Activities::CodeActivity<TResult>, System::Activities::XamlIntegration::IValueSerializableExpression
public sealed class LambdaValue<TResult> : System.Activities.CodeActivity<TResult>, System.Activities.XamlIntegration.IValueSerializableExpression
type LambdaValue<'Result> = class
    inherit CodeActivity<'Result>
    interface IValueSerializableExpression
Public NotInheritable Class LambdaValue(Of TResult)
Inherits CodeActivity(Of TResult)
Implements IValueSerializableExpression

Type Parameters

TResult

The type of value returned by the expression.

Inheritance
Implements

Remarks

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.

Constructors

LambdaValue<TResult>(Expression<Func<ActivityContext,TResult>>) LambdaValue<TResult>(Expression<Func<ActivityContext,TResult>>) LambdaValue<TResult>(Expression<Func<ActivityContext,TResult>>) LambdaValue<TResult>(Expression<Func<ActivityContext,TResult>>)

Initializes a new instance of the LambdaValue<TResult> class using the specified expression.

Methods

CacheMetadata(ActivityMetadata) CacheMetadata(ActivityMetadata) CacheMetadata(ActivityMetadata) CacheMetadata(ActivityMetadata)

Not implemented. Use CacheMetadata(CodeActivityMetadata) instead.

(Inherited from CodeActivity<TResult>)
CacheMetadata(CodeActivityMetadata) CacheMetadata(CodeActivityMetadata) CacheMetadata(CodeActivityMetadata) CacheMetadata(CodeActivityMetadata)

Creates and validates a description of the activity's arguments, variables, child activities, and activity delegates.

(Inherited from CodeActivity<TResult>)
CanConvertToString(IValueSerializerContext) CanConvertToString(IValueSerializerContext) CanConvertToString(IValueSerializerContext) CanConvertToString(IValueSerializerContext)

This 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.

ConvertToString(IValueSerializerContext) ConvertToString(IValueSerializerContext) ConvertToString(IValueSerializerContext) ConvertToString(IValueSerializerContext)

Throws 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.

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
Execute(CodeActivityContext) Execute(CodeActivityContext) Execute(CodeActivityContext) Execute(CodeActivityContext)

When implemented in a derived class, performs the execution of the activity.

(Inherited from CodeActivity<TResult>)
GetHashCode() GetHashCode() GetHashCode() GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetType() GetType() GetType() GetType()

Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
OnCreateDynamicUpdateMap(UpdateMapMetadata, Activity) OnCreateDynamicUpdateMap(UpdateMapMetadata, Activity) OnCreateDynamicUpdateMap(UpdateMapMetadata, Activity) OnCreateDynamicUpdateMap(UpdateMapMetadata, Activity)

Raises an event when creating a map for the dynamic update.

(Inherited from CodeActivity<TResult>)
ShouldSerializeDisplayName() ShouldSerializeDisplayName() ShouldSerializeDisplayName() ShouldSerializeDisplayName()

Indicates whether the DisplayName property should be serialized.

(Inherited from Activity)
ToString() ToString() ToString() ToString()

Returns a String that contains the Id and DisplayName of the Activity.

(Inherited from Activity)

Properties

CacheId CacheId CacheId CacheId

Gets the identifier of the cache that is unique within the scope of the workflow definition.

(Inherited from Activity)
Constraints Constraints Constraints Constraints

Gets a collection of Constraint activities that can be configured to provide validation for the Activity.

(Inherited from Activity)
DisplayName DisplayName DisplayName DisplayName

Gets or sets an optional friendly name that is used for debugging, validation, exception handling, and tracking.

(Inherited from Activity)
Id Id Id Id

Gets an identifier that is unique in the scope of the workflow definition.

(Inherited from Activity)
Implementation Implementation Implementation Implementation

Not supported.

(Inherited from CodeActivity<TResult>)
ImplementationVersion ImplementationVersion ImplementationVersion ImplementationVersion

Gets or sets the implementation version of the activity.

(Inherited from CodeActivity<TResult>)
Result Result Result Result

Gets or sets the result argument for the Activity<TResult>.

(Inherited from Activity<TResult>)
ResultType ResultType ResultType ResultType

When implemented in a derived class, gets the type of an activity OutArgument.

(Inherited from ActivityWithResult)

Applies to