Activity<TResult> Class

Reference

Definition

Namespace:: System.Activities

Assembly:: System.Activities.dll

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

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.

generic <typename TResult>
public ref class Activity abstract : System::Activities::ActivityWithResult

[System.ComponentModel.TypeConverter(typeof(System.Activities.XamlIntegration.ActivityWithResultConverter))]
public abstract class Activity<TResult> : System.Activities.ActivityWithResult

[<System.ComponentModel.TypeConverter(typeof(System.Activities.XamlIntegration.ActivityWithResultConverter))>]
type Activity<'Result> = class
    inherit ActivityWithResult

Public MustInherit Class Activity(Of TResult)
Inherits ActivityWithResult

Type Parameters

TResult

The type of the return value of the activity.

Inheritance: Object

Activity

ActivityWithResult
Activity<TResult>

Derived: System.Activities.AsyncCodeActivity<TResult>

System.Activities.CodeActivity<TResult>

System.Activities.DynamicActivity<TResult>

System.Activities.Expressions.AndAlso

System.Activities.Expressions.OrElse

More…

Attributes: TypeConverterAttribute

Examples

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)),
        };
    }
}

Remarks

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.

Constructors

Activity<TResult>()

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

Properties

CacheId	Gets the identifier of the cache that is unique within the scope of the workflow definition. (Inherited from Activity)
Constraints	Gets a collection of Constraint activities that can be configured to provide validation for the Activity. (Inherited from Activity)
DisplayName	Gets or sets an optional friendly name that is used for debugging, validation, exception handling, and tracking. (Inherited from Activity)
Id	Gets an identifier that is unique in the scope of the workflow definition. (Inherited from Activity)
Implementation	Gets or sets the delegate that returns an Activity that contains the execution logic. (Inherited from Activity)
ImplementationVersion	Gets or sets the version of the implementation used. (Inherited from Activity)
Result	Gets or sets the result argument for the Activity<TResult>.
ResultType	When implemented in a derived class, gets the type of an activity OutArgument. (Inherited from ActivityWithResult)

Methods

CacheMetadata(ActivityMetadata)	Creates and validates a description of the activity's arguments, variables, child activities, and activity delegates. (Inherited from Activity)
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
FromValue(TResult)	Returns a Activity<TResult> expression that evaluates to the given value.
FromVariable(Variable)	Returns a Activity<TResult> expression that evaluates to the given Variable.
FromVariable(Variable<TResult>)	Returns a Activity<TResult> expression that evaluates to the given Variable<T>.
GetHashCode()	Serves as the default hash function. (Inherited from Object)
GetType()	Gets the Type of the current instance. (Inherited from Object)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
OnCreateDynamicUpdateMap(UpdateMapMetadata, Activity)	Raises an event when creating dynamic update map. (Inherited from Activity)
ShouldSerializeDisplayName()	Indicates whether the DisplayName property should be serialized. (Inherited from Activity)
ToString()	Returns a String that contains the Id and DisplayName of the Activity. (Inherited from Activity)

Operators

Implicit(TResult to Activity<TResult>)	Returns a Activity<TResult> expression that evaluates to the given value.
Implicit(Variable to Activity<TResult>)	Returns a Activity<TResult> expression that evaluates to the given Variable.
Implicit(Variable<TResult> to Activity<TResult>)	Returns a Activity<TResult> expression that evaluates to the given Variable<T>.

Applies to

Κοινή χρήση μέσω