Getting a copy of a DLL in the GAC

Getting a copy of a DLL in the GAC

A few weeks ago, Patrick Wellink blogged about how you would get a copy of a DLL when it's in the GAC. Today I had the same problem but after reading Patrick's blog post and the comments, I decided to write a small console application to make that process somewhat easier.

This application takes at least two arguments. The first argument is the physical path to the GAC on the system. The second is the path where the DLL needs to be copied. The following example copies all Crystal components in the GAC to a backup folder:

GetGACAssemblies C:\Windows\Assembly C:\Projects\GACBackup Crystal*.dll

If you just need a backup of all GAC assemblies, simply do something like this:

GetGACAssemblies C:\Windows\Assembly C:\Projects\GACBackup

To build the application, I used the ScanDirectory class I blogged about earlier. The code for this console application is really simple:

using System;

using System.IO;

namespace GetGACAssemblies

{

    class Program

    {

        private static string _targetPath;

        static void Main(string[] args)

        {

            // You need at least two arguments

            if (args.Length >= 2)

            {

                // Get the target path and make sure it exists

                _targetPath = args[1];

                if (!_targetPath.EndsWith(@"\"))

                {

                    _targetPath += @"\";

                }

                if (!Directory.Exists(_targetPath))

                {

                    Directory.CreateDirectory(_targetPath);

                }

                // Setup the directory scanner object

                ScanDirectory scanner = new ScanDirectory();

                scanner.FileEvent += new ScanDirectory.FileEventHandler(scanner_FileEvent);

                if (args.Length == 2)

                {

                    scanner.SearchPattern = "*.dll";

                }

                else

                {

                    scanner.SearchPattern = args[2];

                }

                // Start the scan

                scanner.WalkDirectory(args[0]);

            }

        }

        static void scanner_FileEvent(object sender, FileEventArgs e)

        {

            string newFile = _targetPath + e.Info.Name;

            if (File.Exists(newFile))

            {

                File.Delete(newFile);

            }

            File.Copy(e.Info.FullName, newFile);

        }

    }

}

You can download the code for the console application here.

Getting a copy of a DLL that's only in the GAC

Ok probably there is a simpeler way of doing this but i googled for it and couldn't find it. So here is the story.

I needed a specific DLL that was placed in the GAC by the install of BizTalk. I needed the DLL cause I needed to ad a reference in my C# project. If anybody knows how to add a Reference to a DLL tha's in the GAC I'll be interested as well.

But I couldn't find a way to do it so I needed a copy of that dll.

So you use explorer and Browse to the GAC.

But you can't make a copy of it, You can see all the details and stuff but you cannot copy it. But if you open a Command prompt and go to the same directory stuff looks different....

And for sure when you go to the correct directory you can get the underlying DLL.

There are probably easier ways of doing this but I thought I share this method of doing it.