Store data from async web service call with Silverlight

Did you ever tried to store data on Silverlight from an async web service call using SaveFileDialog - and get told it doesn’t work?
But that is only half the truth. Here it how it works!

Visual Studio, TFS and WinMerge

WinMerge is a great and handy tool for comparing and merging source code and other textual file types within a team development environment.

I use it since a few years and therefore I also want to use it with VS2010 and TFS and it’s very simple.

Just go through

Tools > Options > Source Control > Visual Studio Team Foundation Server > Hit <Configure Tools>

Here you can setup custom tools for comparing and merging.

Add a new tool and provide the installation path to WinMerge and some command line arguments like (explanation follows):

Hit <OK> and do the same with merge.

Command line switches for WinMerge are (copied from the WinMerge documentation):

• /r compares all files in all subfolders (recursive compare).

• /e enables you to close WinMerge with a single Esc key press.

• /f applies a specified filter to restrict the comparison. The filter can be a filemask or the name of a file filter

• /x closes WinMerge (after displaying an information dialog) when you start a comparison of identical files.

• /s limits WinMerge windows to a single instance.

• /ul prevents WinMerge from adding the left path to the Most Recently Used (MRU) list.

• /ur prevents WinMerge from adding the right path to the Most Recently Used (MRU) list.

• /u prevents WinMerge from adding either path (left or right) to the Most Recently Used (MRU) list.

• /wl opens the left side as read-only.

• /wr opens the right side as read-only.

• /minimize starts WinMerge as a minimized window.

• /maximize starts WinMerge as a maximized window.

• /dl specifies a description in the left side title bar, overriding the default folder or filename text.

• /dr specifies a description in the right side title bar, just like /dl.

• leftpath specifies the folder, file or project file to open on the left side.

• rightpath specifies the folder, file or project file to open on the right side.

• outputpath Specifies an optional output folder where you want merged result files to be saved.

• conflictfile Specifies a conflict file, typically generated by a Version control system.

Resources:
flurfunk.sdx-ag.de
www.prowebconsult.com
Winmerge manual

Auto checkout with VS2010 and TFS2010 not working

On my project “Simple Proxy Switch” I decided to access codeplex version control system through VS2010 TFS integration.

As I mainly use Subversion I like that you can edit files without locking them. As I arrived on TFS I missed this a lot. Searching for other options I found the ability of TFS to check out files on edit.

Nevertheless it doesn’t work for me. Files still are not getting checked out on edit.

Fast search at the web discovers some helpful links mainly again in the Microsoft Developer Network.

The missing setting was the binding of the solution to TFS. This can be achieved on Selecting solution and than go through

File –> Source Control –> Change Source Control

select solution and hit <Bind>.

Et voilà. Now VS2010 checks out files on edit.

You are logged into a Temporary Profile

Shortly my new syspreppted virtual machine say’s “You are logged into a temporary profile.” WFT?

After a short search with my search engine of choice I found a solution for this on the Windows 7 IT Pro Forums. Detailed information about user profiles can be found on About User Profiles.

So this has been caused because I used this machine with the same domain account before I had sysprepped it.

In short:
Search user profile at

C:\Users\%username%

and delete it.
Open the registry editor and search for the profile with the corresponding SID at registry key

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsNT\CurrentVersion\ProfileList

and delete it.

Restart and try to log on. Problem should be solved.

Detect current network setting with C#

In cause of my latest project Simple Proxy Switch I had to face the challenge of detecting the setting of the current network the computer is connected to.

Now here’s my snippet how do I retrieve the current network setting:

// zero conf ip address
IPAddress zeroConf = new IPAddress(0);
// get current assigned addresses
IPAddress[] hostAddresses = Dns.GetHostAddresses(Dns.GetHostName());

var networkData = NetworkInterface.GetAllNetworkInterfaces()
  // filter running network interfaces
  .Where(network => network.OperationalStatus == OperationalStatus.Up)
  // filter unknown interfaces
  .Where(network => network.NetworkInterfaceType != NetworkInterfaceType.Unknown)
  // filter loopback interfaces
  .Where(network => network.NetworkInterfaceType != NetworkInterfaceType.Loopback)
  // get the properties
  .Select(network => network.GetIPProperties())
  // filter initialized gateways
  .Where(ipProps => ipProps.GatewayAddresses.All(gateway => gateway.Address != zeroConf))
  // filter and get ip addresses
  .SelectMany(ipProps => ipProps.UnicastAddresses.Where(ucAddress => hostAddresses.Contains(ucAddress.Address)))
  .Where(ucAddress => hostAddresses.Contains(ucAddress.Address))
  // simply use the first
  .FirstOrDefault();

Be the force with you!

Network drives unavailable while running programs under Admin privileges

Since the installation of VS 2010 I discovered that some network shares are unavailable to access with Visual Studio 2010. This is disturbing because my shared settings living on a network share.
I guessed this was caused because of VS2010

%VSINSTALLDIR%\Common7\IDE\devenv.exe

is treated to be executed as administrator also the VSLauncer.exe located in

%CommonProgramFiles%\microsoft shared\MSEnv\VSLauncher.exe

Yesterday I spent now 2 min with google and found a solution.
The problem is caused by using different access tokens for user currently logged in and program that runs with admin privileges. Further information can be found here.
This problem can be solved by enable sharing of access tokens between current (filtered) and admin access. This can be done by creating registry key

EnableLinkedConnections

located under

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\System

and setting it’s DWORD value to ‘1’. Detailed information can be found here.

Have fun.

ReSharper shortcuts for VS2010 to improve TDD productivity

ReSharper is a powerful tool that helps you to produce better code.
One very nice feature is to run your NUnit-Test within the integrated Testrunner. But it’s a little bit annoying to click on the play button every time you want to run a test.
The easiest thing to handle this is to set up keyboard shortcuts to run you tests. Visual Studio supports setting shortcuts for a lot of actions, so let’s go straight ahead and set up shortcuts.
Simple open the options dialog for keyboard settings via Tools –> Customize –> hit “Keyboard” button and then search for

ReSharper.ReSharper_UnitTest_

As result you get something like the following:


Now you can set the shortcut for the desired operation.

I have chosen combinations of

Ctrl + Shift + Alt & '<'

A short explanation of the shown possibilities:

• ContextRun runs the current selected test
• ContextDebug debugs the current selected test
• RunCurrentSession reruns a previous test session
• RunSolution runs all test within the solution

Have fun.

Remote Certificate validation

Sooner or later every developer has to deal on retrieving information from some resource accessible through HTTP protocol.

While it is easy to get this information from unsecured HTTP resources it's often the case that such a resource is only available for secured access through HTTP.

In that case and to ensure that this connection is trusted you have to check the server certificate for that connection.
Some sample piece of code to access and download data over http can look like this one:

string data = String.Empty;
using (WebClient webClient = new WebClient())
{
   byte[] rawData = webClient.DownloadData(new Uri(/* path to resource */));

   using (MemoryStream memStream = new MemoryStream(rawData))
   {
      using (StreamReader reader = new StreamReader(memStream, true))
      {
         data = reader.ReadToEnd();
      }
   }
}

This code works well for connections through HTTP.

Now you have to access the same resource over HTTPS and this is where you have to face a new challenge:

Validation of Certificates.

In the case of .NET there is the ServicePointManager that let you intercept the mechanism of validation.
It defines the ServerCertificateValidationCallback method which is called on secure resource access.

The adjusted code is now something like this:
string data = String.Empty;

using (WebClient webClient = new WebClient())
{
   RemoteCertificateValidationCallback validationCallback =
      (sender, cert, chain, errors) =>
      {
         return true;
      };

   ServicePointManager.ServerCertificateValidationCallback += validationCallback;

   try
   {
      byte[] rawData = webClient.DownloadData(new Uri(/* path to resource */));

      using (MemoryStream memStream = new MemoryStream(rawData))
      {
         using (StreamReader reader = new StreamReader(memStream, true))
         {
            data = reader.ReadToEnd();
         }
      }
   }
   finally
   {
      ServicePointManager.ServerCertificateValidationCallback -= validationCallback;
   }
}

This code simply declares all certificates as valid which is some kind of stupid.

Let's focus on the validation of the certificate. Feel free to implement you own code of validation or just simply use .NET integrated features.

Something I did at bugtraqplugin is to use the default validation chain which depends on certificates stored at the Windows certification storage.

My simple approach:
RemoteCertificateValidationCallback validationCallback =

   (sender, cert, chain, errors) =>
   {
      return (certificate as X509Certificate2 ?? new X509Certificate2(certificate)).Verify();
   };

All code put together can be available at source code of bugtraqplugin.

Tech Ed Europe 2010

Finished registration for Tech Ed Europe 2010 from Nov. 8 to Nov. 12 in Berlin, Germany.

msiexec /a - MSI-Installer Error 2203

Discovered MSI installer error 2203 on extracting installer file with following options:

msiexec /a <product.msi> /qb TARGETDIR=%CD%

Still after searching the web I still had no solution so tried to analyse failure with log file examination:

msiexec /a <product.msi> /qb TARGETDIR=%CD% /lv %CD%\Installer.log

After reading a few lines of log the scales fell from my eyes. The source and the destination are the same and the Installer prohibit extracting into source directory directly.

So

msiexec /a <product.msi> /qb TARGETDIR=%CD%\Extract

solves the problem!