NativeActivity Class

Abstract base class for custom activities that implement execution logic using the Execute method, which has full access to the runtime’s features.

System.Object
  System.Activities.Activity
    System.Activities.NativeActivity
      More...

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

public abstract class NativeActivity : Activity

The NativeActivity type exposes the following members.

  NameDescription
Protected methodNativeActivityWhen implemented in a derived class, creates a new instance of the derived class.
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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 propertyCanInduceIdleGets or sets a value that indicates whether the activity can cause the workflow to become idle.
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 propertyImplementationThe execution logic of the activity. (Overrides Activity.Implementation.)
Protected propertyImplementationVersionGets or sets the implementation version of the activity. (Overrides Activity.ImplementationVersion.)
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  NameDescription
Protected methodAbortWhen implemented in a derived class, takes actions in response to the activity being aborted.
Protected methodCacheMetadata(ActivityMetadata)Not implemented. Use the CacheMetadata method instead. (Overrides Activity.CacheMetadata(ActivityMetadata).)
Protected methodCacheMetadata(NativeActivityMetadata)Creates and validates a description of the activity’s arguments, variables, child activities, and activity delegates.
Protected methodCancelWhen implemented in a derived class, runs logic to cause graceful early completion of the activity.
Public methodEquals(Object)Determines whether the specified object is equal to the current object. (Inherited from Object.)
Protected methodExecuteWhen implemented in a derived class, runs the activity’s execution logic.
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 the default hash function. (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.)
Protected methodOnCreateDynamicUpdateMap(NativeActivityUpdateMapMetadata, Activity)Raises an event when creating a map for the dynamic update.
Protected methodOnCreateDynamicUpdateMap(UpdateMapMetadata, Activity)Raises an event when creating a map for the dynamic update. (Overrides Activity.OnCreateDynamicUpdateMap(UpdateMapMetadata, Activity).)
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.)
Protected methodUpdateInstanceUpdates the instance of NativeActivity.
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The following code sample demonstrates creating a class that inherits from NativeActivity<TResult>. This example is from the Custom Composite using Native Activity sample.

public sealed class MySequence : NativeActivity
{
    Collection<Activity> children;
    Collection<Variable> variables;
    Variable<int> currentIndex;
    CompletionCallback onChildComplete;

    public MySequence()
        : base()
    {
        this.children = new Collection<Activity>();
        this.variables = new Collection<Variable>();
        this.currentIndex = new Variable<int>();
    }

    public Collection<Activity> Activities
    {
        get
        {
            return this.children;
        }
    }
    public Collection<Variable> Variables
    {
        get
        {
            return this.variables;
        }
    }
    protected override void CacheMetadata(NativeActivityMetadata metadata)
    {
        //call base.CacheMetadata to add the Activities and Variables to this activity's metadata
        base.CacheMetadata(metadata);
        //add the private implementation variable: currentIndex 
        metadata.AddImplementationVariable(this.currentIndex);
    }                   

    protected override void Execute(NativeActivityContext context)
    {
        InternalExecute(context, null);
    }
    void InternalExecute(NativeActivityContext context, ActivityInstance instance)
    {
        //grab the index of the current Activity
        int currentActivityIndex = this.currentIndex.Get(context);
        if (currentActivityIndex == Activities.Count)
        {
            //if the currentActivityIndex is equal to the count of MySequence's Activities
            //MySequence is complete
            return;
        }

        if (this.onChildComplete == null)
        {
            //on completion of the current child, have the runtime call back on this method
            this.onChildComplete = new CompletionCallback(InternalExecute);
        }
        //grab the next Activity in MySequence.Activities and schedule it
        Activity nextChild = Activities[currentActivityIndex];
        context.ScheduleActivity(nextChild, this.onChildComplete);

        //increment the currentIndex
        this.currentIndex.Set(context, ++currentActivityIndex);
    }
}

.NET Framework

Supported in: 4.6, 4.5, 4

.NET Framework Client Profile

Supported in: 4

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

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.

System.Object
  System.Activities.Activity
    System.Activities.NativeActivity
      System.Activities.Statements.CancellationScope
      System.Activities.Statements.Compensate
      System.Activities.Statements.Confirm
      System.Activities.Statements.Delay
      System.Activities.Statements.DeleteBookmarkScope
      System.Activities.Statements.DoWhile
      System.Activities.Statements.Flowchart
      System.Activities.Statements.ForEach<T>
      System.Activities.Statements.HandleScope<THandle>
      System.Activities.Statements.If
      System.Activities.Statements.Interop
      System.Activities.Statements.InvokeAction
      System.Activities.Statements.InvokeAction<T>
      System.Activities.Statements.InvokeAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10>
      System.Activities.Statements.InvokeAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11>
      System.Activities.Statements.InvokeAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12>
      System.Activities.Statements.InvokeAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13>
      System.Activities.Statements.InvokeAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14>
      System.Activities.Statements.InvokeAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15>
      System.Activities.Statements.InvokeAction<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12, T13, T14, T15, T16>
      System.Activities.Statements.InvokeAction<T1, T2>
      System.Activities.Statements.InvokeAction<T1, T2, T3>
      System.Activities.Statements.InvokeAction<T1, T2, T3, T4>
      System.Activities.Statements.InvokeAction<T1, T2, T3, T4, T5>
      System.Activities.Statements.InvokeAction<T1, T2, T3, T4, T5, T6>
      System.Activities.Statements.InvokeAction<T1, T2, T3, T4, T5, T6, T7>
      System.Activities.Statements.InvokeAction<T1, T2, T3, T4, T5, T6, T7, T8>
      System.Activities.Statements.InvokeAction<T1, T2, T3, T4, T5, T6, T7, T8, T9>
      System.Activities.Statements.InvokeDelegate
      System.Activities.Statements.NoPersistScope
      System.Activities.Statements.Parallel
      System.Activities.Statements.ParallelForEach<T>
      System.Activities.Statements.Persist
      System.Activities.Statements.Pick
      System.Activities.Statements.Rethrow
      System.Activities.Statements.Sequence
      System.Activities.Statements.StateMachine
      System.Activities.Statements.Switch<T>
      System.Activities.Statements.TerminateWorkflow
      System.Activities.Statements.TransactionScope
      System.Activities.Statements.TryCatch
      System.Activities.Statements.While
      System.Activities.Validation.AddValidationError
      System.Activities.Validation.AssertValidation
      System.Activities.Validation.Constraint
      System.ServiceModel.Activities.CorrelationScope
      System.ServiceModel.Activities.InitializeCorrelation
      System.ServiceModel.Activities.TransactedReceiveScope
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