Have a look at some of the new APIs in introduced in System.IO which makes some of the tasks efficient – both performance as well as memory wise.

For example, there are instances when we need the total number of files in a given directory (recursively). In those instances, we think of following two methods :-

System.IO.DirectoryInfo.GetFiles() which returns FileInfo[]

System.IO.Directory.GetFiles() which returns string[] (which contains names)

.NET 4.0 introduced some new methods for IO and two of which are :-

System.IO.DirectoryInfo.EnumerateFiles() which returns IEnumerable<FileInfo>

System.IO.Directory. EnumerateFiles() which returns IEnumerable<string> (which contains names)

Why these two new methods? Because they are efficient because when we use them we don’t have to wait for thw whole FileInfo[] or String[] to return before we could access the collection. From MSDN:-

“TheEnumerateFilesandGetFilesmethods differ as follows: When you useEnumerateFiles, you can start enumerating the collection ofFileInfoobjects before the whole collection is returned; when you useGetFiles, you must wait for the whole array ofFileInfoobjects to be returned before you can access the array. Therefore, when you are working with many files and directories,EnumerateFilescan be more efficient.”

I did some performance comparison ( a small project attached ) and following are the results :-

For 56505 number of files :-

As you can see DirectoryInfo.EnumerateFiles() is faster than DirectoryInfo.GetFiles() and more importantly occupies almost 1/5 of memory in comparison.

Also, regarding Directory.GetFiles(), It is used to fetch the names of the files. But as we can see one can use Directory.EnumerateFiles() which is faster and occupies almost 1/4th of the memory in comparison.

[Task manager showing memory occupied by DirectoryInfo.GetFiles()]

[Task manager showing memory occupied by DirectoryInfo.EnumerateFiles()]

Therefore, when we need to enumerate large number of files, we can look at EnumerateFiles() method.

I was trying to use Unity Apllication Block this morning and following is the code I wrote:-

Interfaces (In the assembly named “Interfaces”. In project :- Interfaces)
namespace Interfaces
{
public interface IDoSomeWork1
{
string DoSomeWork1();
}
}

namespace Interfaces
{
public interface IDoSomeWork2
{
string DoSomeWork2();
}
}

Dependencies (In the assembly named “Entities”. In project :- Entities)
namespace Entities
{
public class ClassB : IDoSomeWork1
{
public string DoSomeWork1()
{
return this.ToString();
}
}
}

namespace Entities
{
public class ClassC : IDoSomeWork2
{
public string DoSomeWork2()
{
return this.ToString();
}
}
}

Class (In project :- UsingUnity)
public class ClassA
{
[Dependency]
public IDoSomeWork1 DoSomeWork1 { get; set; }
[Dependency]
public IDoSomeWork2 DoSomeWork2 { get; set; }

public void SomeMethodInClassA()
{
Console.WriteLine(DoSomeWork1.DoSomeWork1());
Console.WriteLine(DoSomeWork2.DoSomeWork2());
}
}

App.Config (In a console application project :- ConsoleUsingUnity)
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<configSections>
<section name="unity"
type="Microsoft.Practices.Unity.Configuration.UnityConfigurationSection,
Microsoft.Practices.Unity.Configuration" />
</configSections>
<unity>
<containers>
<container>
<types>
<type type="Interfaces.IDoSomeWork1, Interfaces"
mapTo="Entities.ClassB, Entities" />
<type type="Interfaces.IDoSomeWork2, Interfaces"
mapTo="Entities.ClassC, Entities" />
</types>
</container>
</containers>
</unity>
</configuration>


The client (In a console application project :- ConsoleUsingUnity)
public class Class1
{
static void Main(string[] args)
{
IUnityContainer container = new UnityContainer();

// Load from config file
UnityConfigurationSection section = (UnityConfigurationSection)ConfigurationManager.GetSection(“unity”);
section.Configure(container);

ClassA classA = container.Resolve<ClassA>();
classA.SomeMethodInClassA();
}
}

And when I run the client, I get the following error at section.Configure(container);:-

The given assembly name or codebase was invalid. (Exception from HRESULT: 0x80131047)

Solution
I must state that the code above didn’t give me any problem (build error etc.). It just gave me the error I stated in my question. The problem with Unity at this point of time is that It does not provide which assembly or a which types in the assembly could not be loaded. This is a requested feature.

In my case It was a missing assembly problem. I didn’t reference Entities assembly in to the client application project. It seems that that “Entities” assembly could be resolved only at the run-time (since it didn’t give me any compile time error). However, the run-time error was also not useful at all.

I had a look a Fusion Log viewer (It should be in the .NET SDK folder). What a gem of an utility It is. It can log all kind of assembly bindings (all or only failures) and It give a very neat description of which assembly could not load. Very helpful!

I added the the reference of the “Entities” assembly to the client application and It was able to call methods from the dependencies (ClassB and ClassC).

So, next time, you get this “The given assembly name or codebase was invalid” error, try Fusion Log Viewer. It wont help you in finding which types couldn’t be loaded. However,at least you will be sure all your assemblies are getting loaded correctly.