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.