Work with Arguments in Workflow

Introduction : In Windows Workflow Foundation, arguments represent the flow of data into and out of an activity. An activity has a set of arguments and they make up the signature of the activity. An argument is bound using an expression that returns value.

Let see how to create FlowDecision activity.

Step : 1 Create an Workflow Console Application.

Define the Class.

Step : 2 Goto Solution Explorer and right-click.

Select Add->NewItem->Class.
Select Class template and specify the name as order.cs.
Click Add option.

Step : 3 Go to Solution Explorer and see.

Step : 4 Go to order.cs Class and write a code.

Code :

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace op1
{

public class OrderItem
{
public int ID { get; set; }
public int Quantity { get; set; }
public string Code { get; set; }
public string Description { get; set; }
}
public class order
{
public order()
{
Items = new List<OrderItem>();
}
public int orderid { get; set; }
public string Description { get; set; }
public decimal Weight { get; set; }
public string ShippingMethod { get; set; }
public List<OrderItem> Items { get; set; }
}
}

Implementing the Workflow.

Solution template created a Workflow file name Workflow1.xaml.

Step : 5 Solution Explorer->right-click

Select Rename and change a name.
Open file and change Class attribute.

Defining the Arguments.

Step : 6 Open the OrderWF.xaml file and define the arguments.

Click the Arguments button at the bottom left of the Workflow designer.
Click the Create Argument Link and write Name as Orderinfo.
Click argument type and select Browser for types.

Step : 7 Designing the Workflow.

Drag a Sequence ,WriteLine, Assign activity, Switch<T> activity.
Right -click and write a DisplayName.

Switch<T> activity works like a switch statement in c#. it allows we to execute a sequence activities.

Step : 8 Select Switch<T>->Expression property.

Write a Expression.
Click->Add new case link.
Enter the case value.

Step : 9 Go to Solution Explorer->right-click.

OrderWF.xaml->ViewCode and write a code.

Code :

<Switch x:TypeArguments="x:String" DisplayName="Handling charges" Expression="[orderinfo.ShippingMethod]"
sap:VirtualizedContainerService.HintSize="473,256">
<Switch.Default>
<Add x:TypeArguments="x:Decimal, x:Decimal, x:Decimal" DisplayName="Add 8" Left="[Amount]" Result="[Amount]" Right="[9.0D]" />
</Switch.Default>
<Add x:TypeArguments="x:Decimal, x:Decimal, x:Decimal" x:Key="Day" DisplayName="Add 8" sap:VirtualizedContainerService.HintSize="453,100"
Left="[Amount]" Result="[Amount]" Right="[18.0D]" />
<Add x:TypeArguments="x:Decimal, x:Decimal, x:Decimal" x:Key="firstday" DisplayName="Add 9" sap:VirtualizedContainerService.HintSize="453,100"
Left="[Amount]" Result="[Amount]" Right="[17.0D]" />
</Switch>
<Assign DisplayName="charges" sap:VirtualizedContainerService.HintSize="473,57">
<Assign.To>
<OutArgument x:TypeArguments="x:Decimal">[amount]</OutArgument>
</Assign.To>
<Assign.Value>
<InArgument x:TypeArguments="x:Decimal">[amount + (orderinfo.Weight * 0.8D)]</InArgument>

Step : 10 Drag Assign activity and set the DisplayName and write a code for value property.

Code :

"The total amount is : "amount.ToString();

Step : 11 Go to program.cs file and write a code for Workflow.

Code :

using System;
using System.Linq;
using System.Activities;
using System.Activities.Statements;
using System.Collections.Generic;
namespace op1
{
class Program
{
static void Main(string[] args)
{
order myOrder = new order()
{
orderid = 1,
Description = "Need some stuff",
ShippingMethod = "firstday",
Weight = 90
};
IDictionary<string, object> input = new Dictionary<string, object> { { "orderinfo", myOrder } };
IDictionary<string, object> output = WorkflowInvoker.Invoke(new orderWF(), input);
decimal amount = (decimal)output["amount"];
Console.WriteLine("Workflow returned ${0} for my order amount", amount);
Console.WriteLine("Hi");
Console.ReadLine();
}
}
}

Step : 12 Press F5 and run it.

2 Comments

Join the conversation! Your thoughts help the community grow.

rashik rash8y ago
I declare inarguments for the workflow. I pass the values during invoking but it gives following exception"The following keys from the input dictionary do not map to arguments and must be removed: x. Please note that argument names are case sensitive."Thanks in advance
Arun Sharma12y ago
not very clear. lot of steps are missing in screenshots and explaination