William Bartholomew

When setting default values for dependency properties in Workflow Foundation there are two steps:

1. Pass a PropertyMetadata object containing the default value to the DependencyProperty constructor (Line 8). This defaults the value of the property to the passed value.
2. Apply the DefaultValue attribute to the property (Line 14). This provides the default value to the PropertyGrid which allows functionality such as the property appearing bold if the value is different to the default and the right-click Reset option to set the property back to the default. 

For example:

   1:  Private Const DefaultPort As Integer = 25
   2:   
   3:  Public Shared PortProperty As DependencyProperty = _
   4:      DependencyProperty.Register( _
   5:          "Port", _
   6:          GetType(Integer), _
   7:          GetType(SendEmail), _
   8:          New PropertyMetadata(DefaultPort) _
   9:      )
  10:   
  11:  <Description("Port")> _
  12:  <Category("Input")> _
  13:  <Browsable(True)> _
  14:  <DefaultValue(DefaultPort)> _
  15:  <DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)> _
  16:  Public Property Port() As Integer
  17:      Get
  18:          Return (CType((MyBase.GetValue(SendEmail.PortProperty)), Integer))
  19:      End Get
  20:      Set(ByVal Value As Integer)
  21:          MyBase.SetValue(SendEmail.PortProperty, Value)
  22:      End Set
  23:  End Property

I was using Workflow Foundation as part of an internal process recently and I couldn’t work out why the tracking events generated by the SqlTrackingService weren’t being written to the tracking database until the workflow completed or was terminated.

The issue was that the SqlTrackingService is transactional by default and the transaction isn’t committed until the workflow completes or is terminated. This can be changed by setting the IsTransactional property to False before adding the service to the WorkflowRuntime’s services collection.

http://msmvps.com/blogs/theproblemsolver/archive/2006/09/28/Tracking-in-Workflow-Foundation.aspx

I was working on a project recently where I had a solution with a project that self-hosted a WCF service and another project containing the service itself.

When running the solution with self-hosted project as the startup Visual Studio would also run the built-in WCF service host resulting in a clash for URLs/ports.

The solution is in the WCF Options tab in the service’s project properties. If you clear the Start WCF Service Host When Debugging Another Project In The Same Solution checkbox Visual Studio won’t run the built-in WCF service host unless the service project is the start-up project.

Dim totalSize As Decimal = (Aggregate file In New System.IO.DirectoryInfo(“c:\dev\”).GetFiles(“*.*”, IO.SearchOption.AllDirectories) Into Sum(file.Length)) / 1024 / 1024