Custom Activity in Workflow

Introduction: The Custom activities are the units of work that are composed to produce workflow based functionality. In WF4, activities explicitly declare their inputs and outputs via arguments.

Step 1: Open Visual Studio and select the File option.

Select New->Project->Workflow Console Application.
Drag s Sequence activity and s WriteLine activity.
Go to properties and write a Text "started application".

Let see how to create Sequential Workflow :

Step 2: Open Visual Studio 2010.

Go to File->New->Project option.
Select Visual C#->Workflow->.NET Framework 3.5.
Select Sequential Workflow Console Application.
Click OK .

After creating the Application, the designer window look like this:

Step 3 : Add an activity from Toolbox for Workflow.

Add a Code activity in Workflow.
Double click in codeActivity1 and write the following code.

Code :

namespace WorkflowLibrary1
{
public sealed partial class Workflow1 : SequentialWorkflowActivity
{
public Workflow1()
{
InitializeComponent();
}
private void codeActivity1_ExecuteCode(object sender, EventArgs e)
{
Console.WriteLine("start 3.5 workflow");
}
private void codeActivity2_ExecuteCode(object sender, EventArgs e)
{
Console.WriteLine("finish 3.5 workflow");
}
}
}

Step 4 : Go to Workflow1.cs [Desaign] drag another codeActivity and write the below code.

Code :

namespace WorkflowLibrary1
{
public partial class customActivity1 : SequenceActivity
{
public customActivity1()
{
InitializeComponent();
}
public static DependencyProperty MessageProperty = DependencyProperty.Register("Message", typeo
(string), typeof(customActivity1));
[DescriptionAttribute("Message")]
[BrowsableAttribute(true)]
[DesignerSerializationVisibilityAttribute
(DesignerSerializationVisibility.Visible)]
public string Message
{

get
{
return ((string)(base.GetValue(MessageProperty)));
}
set
{
base.SetValue(MessageProperty, value);
}
}
private void codeActivity1_ExecuteCode(object sender, EventArgs e)
{
Console.WriteLine(this.Message);
}
}
}

Step 5 : Go to Solution Explorer and right-click.

Select Project->Add Reference.
Select SequentialWorkflowLibrary1.
Press F6 to rebuild the solution.

Step 6 : Go to workflow1.xaml file.

Drag a Interop activity below the WriteLine activity.
Click browse and select Workflow1.
Drag WriteLine activity below the Interop activity.
Enter the Text property "Workflow finished".

Creating a Custom Activity:

Step 7: Go to Solution Explorer and right-click.

Select WorkflowLibrary->Add->New Item.
Select Activity and click on the Add option.
Activity.cs designer option show.

Throwing an Exception:

Step 8: Open Custom.cs [Design] option.

Drag Throw activity.
Go to property options and select FaultType.
Select mscorlib assembly->System namespace.
Select InvalidProgramException.

Invoke Custome Activity:

Step 9 : Drag a WriteLine activity onto the Catch section.

Write the Text property "Custome 3.5 activity".

Step 10 : Press F5 to run the application.