Software Factory

Load and unload assemblies

Pedro Rainho — Sun, 15 Mar 2009 17:59:14 GMT

Last week, I had a problem that probably some .Net developer had faced. The problem consists in load and unload an assembly?.

Can I do that??? Well, I can’t do it in a simple way. One of the things that Assembly doesn’t support in unload, check this post to see why.

So, like I wrote, last week I was developing a new feature for a software factory and that feature consisted in get all references and do something else.

My recipe does something like this:

Get project assembly
Copy the assembly DLL to a location
Get all assembly references
Generate a file

Do number 1 is simple.

Do number 2 is also simple, but has a problem.

Do number 3 is also simple, but has a problem.

Do number 4 is simple.

I’m going to explain first problem number 3 then problem 2

The problem with number 3 it’s because I load a assembly and they I get referenced assemblies. To get referenced assemblies I just do:

Assembly assembly = Assembly.LoadFrom(@"c:\myAssembly.dll");
AssemblyName[] references = assembly.GetReferencedAssemblies();

This piece of code has a problem, since I’m loading the assembly and they get referenced assemblies the file myAssembly.dll is now locked this means that the next time I try to run number 2 I will get an exception and the file will not ne copied. And this is why I had problem number 2.

Now, how can I load the assembly and then unload that assembly so the file won’t be locked???

I came across some solutions.

One of the possible solutions is just copy the assembly to something unique like {GUID}.DLL and then load that {GUID}.DLL, and do everything I need to do, this way I won’t lock my file.
1. Problem: I will have the assembly {GUID}.DLL loaded (in memory) every time, and can’t delete file {GUID}.DLL, because it’s locked. And finally I can’t unload unless I close Visual Studio.
Why don’t I just load the assembly into an array of bytes and then load the assembly, like this:
```
Assembly assembly = Assembly.Load(File.ReadAllBytes(@"c:\myAssembly.dll"));
```
1. Problem: I can do this and my file will not be locked but that array of bytes will be in memory and my visual studio memory will grow every time I run that recipe. That memory will be released only when I close the Visual Studio.
I can load the assembly in a new AppDomain and then unload the AppDomain.
1. Problem: tThis was a strange problem and I don’t know why but I load the assembly in a new AppDomain and that assembly become part of the new AppDomain and the AppDomain.Current. This was strange. Don’t know if I was doing something wrong. Now since the Assembly is loaded in AppDomain.Current I wasn’t able to copy the file, because it was locked.
The last solution I came across to load the assembly and unload it. This solution Consists in create a new AppDomain and then use method DoCallBack:

Here it is the source code:

AppDomainSetup setup = new AppDomainSetup();
setup.ApplicationBase = ApplicationBasePath;

AppDomain newDomainReferences = AppDomain.CreateDomain("AppDomain", null, setup);

CallBackAssemblyReferences call = new CallBackAssemblyReferences(newDomainReferences, filepath);
newDomainReferences.DoCallBack(new CrossAppDomainDelegate(call.LoadAssemblyReferences));
AssemblyName[] assName = (AssemblyName[])newDomainReferences.GetData("AssemblyReferences");

AppDomain.Unload(newDomainReferences);

This solution enables me to do a callback in a different domain. My class CallBackAssemblyReferences just does this:

[Serializable]
internal class CallBackAssemblyReferences
{
    #region Members Variables
    private string assemblyFile;
    private AppDomain domain;
    #endregion

    #region Public Implementation
    public CallBackAssemblyReferences()
    {

    }
    public CallBackAssemblyReferences(AppDomain domain, string assemblyFile)
    {
        this.assemblyFile = assemblyFile;
        this.domain = domain;
    }

    public void LoadAssemblyReferences()
    {
        Assembly assembly = this.domain.Load(AssemblyName.GetAssemblyName(this.assemblyFile));

        domain.SetData("AssemblyReferences", assembly.GetReferencedAssemblies());
    }
    #endregion
}

This class has a constructor that receives the new domain I’m working on and the path to the assembly I want to load.

public CallBackAssemblyReferences(AppDomain domain, string assemblyFile)

Then I just have my callback method WITH NO PARAMETERS.

public void LoadAssemblyReferences()

This is the method that will be called when I do

newDomainReferences.DoCallBack(new CrossAppDomainDelegate(call.LoadAssemblyReferences));

The callback method only loads the assembly in the new domain and then sets data in the new domain. These data are the assembly references.

When the DoCallBack returns I just had to do

AssemblyName[] assName = (AssemblyName[])newDomainReferences.GetData("AssemblyReferences");

To get the references I had saved.

Finally I just unload the AppDomain.

Now I can run my recipe every time I need without lock the file and without decrease visual studio performance.

Software Factory – Guidance Migration from Visual Studio 2005 to Visual Studio 2008

Pedro Rainho — Fri, 06 Feb 2009 09:28:32 GMT

Before begin I have to give some credit to my friend Rodrigo Guerreiro because he helped me with this PROBLEM.

First I can say that I wasn’t able to find ANY information in internet about migration. Don’t know if I was looking in the wrong sites but i wasn’t able to find any information.

Now this post reflect what I did in order to create 2 MSI’s files that can be installed in Visual Studio 2005 and Visual Studio 2008. (One MSI to install in VS2005 and another to install in VS2008)

Notice that I didn’t had to migrate my solution to VS2008 in order to create a MSI that installs a factory in VS2008

These was my steps:

Go to the solution folder and, in my case, there was a folder with the project setup. What I did was copy that folder and rename it from XXXSetup to XXXSetup2008.
Inside the folder XXXSetup2008 I rename the file XXXSetup.vdproj to XXXSetup2008.vdproj
Then I edit file XXXSetup2008.vdproj (With notepad :)) and every place I had XXXSetup I rename it to XXXsetup2008 (Very Careful with this point because you can mess up with the project and start from the begining). In my case I just had to do this renames:
1. "ProjectName" = "8:XXXSetup" para "ProjectName" = "8:XXXSetup2008"
2. "OutputFilename" = "8:Release\\XXXSetup.msi" para "OutputFilename" = "8:Release\\XXXSetup2008.msi"
After this I open the solution in VS2005 and added the project XXXSetup2008.vdproj to my solution
With the project XXXSetup2008 selected.
1. In the solution explorer choose “Custom Actions Editor” icon
  1. A window will open with the following custom actions
    -- GuidancePackage[Install], [commit], [roolback], [uninstall]
  3. Click in every single one and on the properties window change it from /Hive=8.0 /Configuration="[TARGETDIR]xxx.xml" to /Hive=9.0 /Configuration="[TARGETDIR]xxx.xml"
Again with the project XXXSetup2008 selected
1. In the solution explorer choose “Launch Conditions Editor” icon
2. A window will open with the following Launch Conditions:
  1. Search Target Machine
  2. Launch Conditions
3. click in every single option (CSharp, RunTime, VS, .NetFramework, C# Language, Guidance Automation Extensions, VS.Net) and in the properties you will have to change every single place you have 8 (VS2005) change it to 9 (VS2008).
5. Here it is what you need to change:
  1. In CSharp change it from:
    SOFTWARE\Microsoft\VisualStudio\8.0\InstalledProducts\Microsoft Visual C#
    To:
    SOFTWARE\Microsoft\VisualStudio\9.0\InstalledProducts\Microsoft Visual C#
  2. In RunTime change it from:
    SOFTWARE\Microsoft\VisualStudio\8.0\InstalledProducts\RecipeManagerPackage
    To:
    SOFTWARE\Microsoft\VisualStudio\9.0\InstalledProducts\RecipeManagerPackage
  3. In VS.Net change it from:
    SOFTWARE\Microsoft\VisualStudio\8.0\Setup\VS
    To:
    SOFTWARE\Microsoft\VisualStudio\9.0\Setup\VS
  4. In VS.Net change it from::
    Visual Studio .NET 8.0 is not installed. Do you want to see information of the product? Click Yes to be directed to a web page, click No to exit.
    To:
    Visual Studio .NET 9.0 is not installed. Do you want to see information of the product? Click Yes to be directed to a web page, click No to exit.

Now Compile and create the MSI’s. The next step is test the Factory in a VS 2008 :) Hope I was able to help. Sure helped me.

Manual guidance uninstall

Pedro Rainho — Wed, 21 Jan 2009 07:29:38 GMT

if for some reason during GAX uninstall you get a error saying that you need to uninstall all guidance's before you uninstall GAX try open this file C:\Documents and Settings\All Users\Application Data\Microsoft\Recipe Framework\RecipeFramework.xml and manually remove the guidance elements present in this file. After you manually remove the elements you are able to uninstall GAX.