C# retry logic code

Question

Hi I have this same issue  No connection could be made because the target machine actively refused it ... from this posting here http://stackoverflow.com/questions/2972600/no-connection-could-be-made-because-the-target-machine-actively-refused-it it suggests some retry logic on the client code but I am not sure where and how to insert the retry logic for my attached code. I would appreciate some help from the experts. Code as attached. thanks.

TAN WhoAMI · Answer

my application runs under .NET Framework 4.0 as seen in the attached picture below:

Amit Choudhary · Answer

It seem like you are running your app under 2.0 instead of 3.5+. Because it's the Palmer library which is trying to load the specific version assembly of System.core. If you're application is loaded with old target framework it won't get loaded.

TAN WhoAMI · Answer

Managed to get the Palmer installed but when I run my application it gives error as Could not load file or assembly 'System.Core Version=2.0.5.0 Culture=neutral PublicKeyToken=7cec85d7bea7798e' or one of its dependencies. The system cannot find the file specified. I try the solution from http://www.nivisec.com/2009/06/could-not-load-file-or-assembly.html but it does not help. I have installed MS Silverlight 2.0 with C:\Program Files\Microsoft SDKs\Silverlight\v2.0\Reference Assemblies\System.Core.dll but its version is 2.0.30523.6 when I >gacutil /l System.Core I have this:

Amit Choudhary · Answer

This is strange I'm using this library in production environment with no issues.

TAN WhoAMI · Answer

Hi Amit Appreciate your response... however I am not able to install Palmer Library on my Visual Studio 2010 with .NET Framework 4.0... I am still contact the author of Palmer Library... Error as below and attached: Each package is licensed to you by its owner. Microsoft is not responsible for nor does it grant any licenses to third-party packages. Some packages may include dependencies which are governed by additional licenses. Follow the package source (feed) URL to determine any dependencies. Package Manager Console Host Version 2.0.30625.9003 Type 'get-help NuGet' to see all available NuGet commands. PM> Install-Package Palmer Successfully installed 'Palmer 0.1.4724.20297'. Successfully uninstalled 'Palmer 0.1.4724.20297'. Install failed. Rolling back... Install-Package : Could not install package 'Palmer 0.1.4724.20297'. You are trying to install this package into a project that targets ' .NETFrameworkVersion=v4.0' but the package does not contain any assembly references that are compatible with that framework. For more i nformation contact the package author. At line:1 char:16 + Install-Package + CategoryInfo : NotSpecified: (:) [Install-Package] InvalidOperationException + FullyQualifiedErrorId : NuGetCmdletUnhandledExceptionNuGet.PowerShell.Commands.InstallPackageCommand Install-Package : Could no t install package 'Palmer 0.1.4724.20297'. You are trying to install this package into a project that targets ' .NETFrameworkVersion=v4.0' but the package does not contain any assembly references that are compatible with that framework. For more i nformation contact the package author. At line:1 char:16 + Install-Package + CategoryInfo : NotSpecified: (:) [Install-Package] InvalidOperationException + FullyQualifiedErrorId : NuGetCmdletUnhandledExceptionNuGet.PowerShell.Commands.InstallPackageCommand

Amit Choudhary · Answer

What ever you want to repeat for a number of times you can put that in retry block. It's basically recursion that you need to do for a reason and to a limit. For e.g. on your exception you may want to try again for a no. of time and then throw the exception. Let say you want to repeat the webrequest first you should refactor your code to get a common function for webrequest. So everytime you call your method to download it gets repeated everywhere in your application if required. you can use Palmer library for adding retry block in your code. sample for retrying the on exception for 5 times: Retry . On WebException >(). For ( 5 ) . With ( context => { // Code that might throw a web exception. for e.g. your webRequest });