AsyncCodeActivity Class

Definition

Namespace:

System.Activities

Assembly:

System.Activities.dll

Manages asynchronous code activity execution from start to completion. This is an abstract class.

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

public abstract class AsyncCodeActivity : System.Activities.Activity

type AsyncCodeActivity = class
    inherit Activity

Public MustInherit Class AsyncCodeActivity
Inherits Activity

Inheritance

Object

Activity

AsyncCodeActivity

Derived

System.Activities.Statements.InvokeMethod

Examples

The following example shows how to derive a class from AsyncCodeActivity to create a custom activity.

public sealed class FileWriter : AsyncCodeActivity
{
    public FileWriter()
        : base()
    {
    }
    protected override IAsyncResult BeginExecute(AsyncCodeActivityContext context, AsyncCallback callback, object state)
    {
        string tempFileName = Path.GetTempFileName();
        Console.WriteLine("Writing to file: " + tempFileName);

        FileStream file = File.Open(tempFileName, FileMode.Create);

        context.UserState = file;

        byte[] bytes = UnicodeEncoding.Unicode.GetBytes("123456789");
        return file.BeginWrite(bytes, 0, bytes.Length, callback, state);
    }
    protected override void EndExecute(AsyncCodeActivityContext context, IAsyncResult result)
    {
        FileStream file = (FileStream)context.UserState;

        try
        {
            file.EndWrite(result);
            file.Flush();
        }
        finally
        {
            file.Close();
        }
    }
}

Constructors

AsyncCodeActivity()

Creates a new instance of the AsyncCodeActivity 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 null or throws an error when there is an attempt to set the value of this property.
ImplementationVersion	Gets or sets the implementation version of the activity.

Methods

BeginExecute(AsyncCodeActivityContext, AsyncCallback, Object)	When implemented in a derived class and using the specified execution context, callback method, and user state, enqueues an asynchronous activity in a run-time workflow.
CacheMetadata(ActivityMetadata)	Not implemented. Use CacheMetadata(CodeActivityMetadata) instead.
CacheMetadata(CodeActivityMetadata)	Serves as a virtual method and converts information obtained by cache reflection into arguments for an asynchronous activity.
Cancel(AsyncCodeActivityContext)	When implemented in a derived class and using the specified execution environment information, notifies the workflow runtime that the asynchronous activity operation has reached an early completion. Serves as a virtual method.
EndExecute(AsyncCodeActivityContext, IAsyncResult)	When implemented in a derived class and using the specified execution environment information, notifies the workflow runtime that the associated asynchronous activity operation has completed.
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
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 a map for the dynamic update.
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)