In one of our current projects we had to access a Microsoft Access Database (.mdb) with PowerShell. I first tried to access the .mdb using the Invoke-SqlCmd Cmdlet from our PowerShell module biz.dfch.PS.System.Data. Unfortunately connecting to the Access database with the Invoke-SqlCmd Cmdlet does not work as it uses SqlClient from the C#/.NET namespace System.Data […]
Bridging the gap between business processes and information systems
* GitHub Ronald Rink http://github.com/dfch
* GitHiub d-fens http://github.com/dfensgmbh
Fix Null Reference Exception in XAML Designer
2017-05-03 by Leave a Comment
During developing a user control for a WPF UI I encountered a strange null reference exception in the XAML designer. Strange thing was, that when I started the application and switched to the control which contained the user control, everything worked fine. I could’ve just ignored this problem. However since it is very inconvenient writing […]
Manual JWT Validation against Azure Active Directory
2017-04-13 by Leave a Comment
For our current WebApi project we decided to implement OAuth2 authentication with Azure Active Directory. As our API needs to support other authentication mechanisms like Basic and Negotiate beside OAuth2 we implemented multiple authentication filters that, where each filter is responsible for a specific authentication mechanism. One of these authentication filters, the BearerAuthenticationFilter, is responsible […]
Get NetworkCredential from PSCredential splits Username into Username and Domain
2017-04-13 by Leave a Comment
During development of a PowerShell binary module I had to do deal with two different credential types (System.Management.Automation.PSCredential and System.Net.NetworkCredential) and came across a behaviour I wanted to write down. The PowerShell binary module I developed contains several Cmdlets. One of them defines a parameter of type System.Management.Automation.PSCredential. Inside the Cmdlet we need to have […]
[NoBrainer] Adding meaningful error messages when using Contract.Result in C#
2017-04-04 by Leave a Comment
We at d-fens use Microsoft Code Contracts every day. And certainly with every great tool there are some things that might benefit from some improvement – and code contracts are no exception. There is one particular annoying thing in that the error message for Contract.Result exceptions strips the generic parameters from it. This in essence […]
Transient Error Handling with automatic Retries in C#
2017-03-18 by Leave a Comment
Inspired by Transient Fault Handling we created a quick helper class to faciliate the automatic retry of various operation that may fail in today’s interconnected environments. Large parts of our Appclusive framework deal with fetching from and pushing information to various backend systems. As they all can (and eventuall will) fail we needed a flexible […]
Creating SignalR Hub Classes on the fly
2017-03-18 by Leave a Comment
Recently I wanted to create SignalR hubs for client notification based on a list of internal queues. As SignalR is creating Hubs based on their type names I had to find an approach for dynamically defining classes based on the given queue list. In this blog post I show a way on how to do […]
Getting Instance by Type Name in StructureMap
2017-03-12 by Leave a Comment
Ever since we are using StructureMap we are also using this as a cheap replacement for Managed Extensibility Framework (MEF), as it allows us to scan arbitrary assembly paths for additional types to inject. As we are also dealing with configuration sections where we specify which plugins or types we want to use in a […]
Calling ResumeBookmark inside a TrackingParticipant returns NotFound
2017-03-11 by Leave a Comment
While creating a process with Windows Workflow Foundation we wanted to communicate between a workflow activity and the workflow application. For this we decided to use Bookmarks and a TrackingParticipant. The idea was that the Activity should create a bookmark to be consumed by a TrackingParticipant which would process something and then pass control back […]
[NoBrainer] Cascading Lambda Expression in C#
2017-03-05 by Leave a Comment
While Converting ODataQueryOptions into LINQ Expressions I needed to cascade different Lambda Expressions via AND and OR. In this post I describe a way on how to easily combine them via a boxing class with operator overriding. The Problem Cascading lambda expressions should be as easy as using a + or && operator: A boxing […]
