Activity<TResult> Class

.NET Framework (current version)
 

An abstract base class used to create composite activities from pre-existing Activity objects, which specifies a result type using the activity’s type specifier.

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


generic<typename TResult>
[TypeConverterAttribute((ActivityWithResultConverter^::typeid))]
public ref class Activity abstract : ActivityWithResult

Type Parameters

TResult

The type of the return value of the activity.

NameDescription
System_CAPS_protmethodActivity<TResult>()

When implemented in a derived class, creates a new instance of the derived class.

NameDescription
System_CAPS_protpropertyCacheId

Gets the identifier of the cache that is unique within the scope of the workflow definition.(Inherited from Activity.)

System_CAPS_protpropertyConstraints

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

System_CAPS_pubpropertyDisplayName

Gets or sets an optional friendly name that is used for debugging, validation, exception handling, and tracking.(Inherited from Activity.)

System_CAPS_pubpropertyId

Gets an identifier that is unique in the scope of the workflow definition.(Inherited from Activity.)

System_CAPS_protpropertyImplementation

(Inherited from Activity.)

System_CAPS_protpropertyImplementationVersion

Gets or sets the version of the implementation used.(Inherited from Activity.)

System_CAPS_pubpropertyResult

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

System_CAPS_pubpropertyResultType

When implemented in a derived class, gets the type of an activity OutArgument.(Inherited from ActivityWithResult.)

NameDescription
System_CAPS_protmethodCacheMetadata(ActivityMetadata)

Creates and validates a description of the activity’s arguments, variables, child activities, and activity delegates.(Inherited from Activity.)

System_CAPS_pubmethodEquals(Object^)

Determines whether the specified object is equal to the current object.(Inherited from Object.)

System_CAPS_protmethodFinalize()

Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection.(Inherited from Object.)

System_CAPS_pubmethodSystem_CAPS_staticFromValue(TResult)

Returns a Activity<TResult> expression that evaluates to the given value.

System_CAPS_pubmethodSystem_CAPS_staticFromVariable(Variable^)

Returns a Activity<TResult> expression that evaluates to the given Variable.

System_CAPS_pubmethodSystem_CAPS_staticFromVariable(Variable<TResult>^)

Returns a Activity<TResult> expression that evaluates to the given Variable<T>.

System_CAPS_pubmethodGetHashCode()

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_protmethodMemberwiseClone()

Creates a shallow copy of the current Object.(Inherited from Object.)

System_CAPS_protmethodOnCreateDynamicUpdateMap(UpdateMapMetadata^, Activity^)

Raises an event when creating dynamic update map.(Inherited from Activity.)

System_CAPS_pubmethodShouldSerializeDisplayName()

Indicates whether the DisplayName property should be serialized.(Inherited from Activity.)

System_CAPS_pubmethodToString()

Returns a String that contains the Id and DisplayName of the Activity.(Inherited from Activity.)

NameDescription
System_CAPS_puboperatorSystem_CAPS_staticImplicit(TResult to Activity<TResult>^)

Returns a Activity<TResult> expression that evaluates to the given value.

System_CAPS_puboperatorSystem_CAPS_staticImplicit(Variable^ to Activity<TResult>^)

Returns a Activity<TResult> expression that evaluates to the given Variable.

System_CAPS_puboperatorSystem_CAPS_staticImplicit(Variable<TResult>^ to Activity<TResult>^)

Returns a Activity<TResult> expression that evaluates to the given Variable<T>.

Activity<TResult> is the base class in the activity type hierarchy. All other activity types with generic type definitions such as CodeActivity<TResult>, NativeActivity<TResult>, AsyncCodeActivity<TResult>, and DynamicActivity<TResult> derive from this class.

The following example shows how to derive a class from Activity<TResult>.

public sealed class AppendString : Activity<string>
{
    // Input argument.
    [RequiredArgument]
    public InArgument<string> Name { get; set; }

    public AppendString()
    {
        // Define the implementation of this activity.
        this.Implementation = () => new Assign<string>
        {
            Value = new LambdaValue<string>(ctx => Name.Get(ctx) + " says hello world"),
            To = new LambdaReference<string>(ctx => Result.Get(ctx)),
        };
    }
}

.NET Framework
Available since 4.0

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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