NativeActivity Class

Definition

public ref class NativeActivity abstract : System::Activities::Activity

public abstract class NativeActivity : System.Activities.Activity

type NativeActivity = class
    inherit Activity

Public MustInherit Class NativeActivity
Inherits Activity

Inheritance

Object

Activity

NativeActivity

Derived

System.Activities.Statements.CancellationScope

System.Activities.Statements.Compensate

System.Activities.Statements.Confirm

System.Activities.Statements.Delay

System.Activities.Statements.DeleteBookmarkScope

More…

Examples

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);  
    }  
}  

Constructors

Properties

Methods

Applies to