It will be also interesting to find out more the licensing under which they are release. Given it is Microsoft and their genetic make-up includes world domination and manipulation strands curled around each other, there must be something lurking under those small prints… so have a thorough read of it before using it in a firm.

For those who are interested in knowing more: http://weblogs.asp.net/scottgu/archive/2007/10/03/releasing-the-source-code-for-the-net-framework-libraries.aspx

To cut the story short, it all began with a review of those two books by Jeff Atwood on his popular blog “Coding Horror”. Jeff was of the view Adam’s book is much better read because of the way it has been presented, with colors, bullet points etc. while Charles’ book is boring to read. Many comments poured in as well about the content, number of pages etc. This included many heavy weights such as Don Box. Charles hit back stating Adam’s is power point like. Adam took a humorous side to it and posted his take on it in his blog.

Anyway, I hope this whole episode will help in improving on how technical books are presented in future. I’m sure many publishers would have taken note of this duel.

Personally, I haven’t read book the books. So can’t comment on it. But from the blog comments that I have been posted, it looks like Jeff’s right and Adam’s book wins hands down.

System.IO.FileNotFoundException: File or assembly name lz2ikglf.dll, or one of its dependencies, was not found.
File name: "lz2ikglf.dll"
at System.Reflection.Assembly.nLoad(AssemblyName fileName, String codeBase, Boolean isStringized, Evidence assemblySecurity, Boolean throwOnFileNotFound, Assembly locationHint, StackCrawlMark& stackMark)
at System.Reflection.Assembly.InternalLoad(AssemblyName assemblyRef, Boolean stringized, Evidence assemblySecurity, StackCrawlMark& stackMark)
at System.Reflection.Assembly.Load(AssemblyName assemblyRef, Evidence assemblySecurity)
at System.CodeDom.Compiler.CompilerResults.get_CompiledAssembly()
at System.CodeDom.Compiler.CompilerResults.get_CompiledAssembly()
at System.Xml.Serialization.Compiler.Compile()
at System.Xml.Serialization.TempAssembly..ctor(XmlMapping[] xmlMappings)
at System.Xml.Serialization.XmlSerializer..ctor(Type type, XmlAttributeOverrides overrides, Type[] extraTypes, XmlRootAttribute root, String defaultNamespace)
at System.Xml.Serialization.XmlSerializer..ctor(Type type, Type[] extraTypes)
at Microsoft.Practices.EnterpriseLibrary.Configuration.SerializerCache.GetSerializer(Type baseType, Type[] types)
at Microsoft.Practices.EnterpriseLibrary.Configuration.Transformer.XmlSerializerTransformer.CreateXmlSerializer(Type valueType)
at Microsoft.Practices.EnterpriseLibrary.Configuration.Transformer.XmlSerializerTransformer.Deserialize(Object section)
at Microsoft.Practices.EnterpriseLibrary.Configuration.ConfigurationBuilder.ReadConfiguration(String sectionName)
at Microsoft.Practices.EnterpriseLibrary.Configuration.ConfigurationManager.GetConfiguration(String sectionName)

=== Pre-bind state information ===
LOG: Where-ref bind. Location = C:\DOCUME~1\SVC_FC~1\LOCALS~1\Temp\1\lz2ikglf.dll
LOG: Appbase = T:\WorkUnitGenerator\
LOG: Initial PrivatePath = NULL
Calling assembly : (Unknown).
===

LOG: Policy not being applied to reference at this time (private, custom, partial, or location-based assembly bind).
LOG: Attempting download of new URL file:///C:/DOCUME~1/SVC_FC~1/LOCALS~1/Temp/1/lz2ikglf.dll.

Looking at the problem, it looks like the System.CodeDom.Compiler compiles the assembly and then while trying to load it back in, it cannot find the file. Hence the System.IO.FileNotFoundException thrown. First thing to check is the write permission on this directory. That seems to be not a problem.

After much googling, came across a suggestion to reinstall .NET framework again. Weird as it seems, on one of the machines, it seems to have done the trick. But on another it didn’t work.

So, if you come across this issue and none of the above worked, then try reinstalling OS. Have fun! Also, don’t forget to leave comment about your experiences if you have come across this.

public struct EmptyDateTime
{
    DateTime dateTime;

public EmptyDateTime(DateTime dateTime)
    {
        this.dateTime = dateTime;
    }

public bool IsEmpty
    {
        get
        {
            return dateTime == DateTime.MinValue;
        }
    }

public static explicit operator DateTime(EmptyDateTime emptyDateTime)
    {
        if (emptyDateTime.IsEmpty)
            throw new InvalidOperationException("DateTime is Empty");
        return emptyDateTime.dateTime;
    }

public static implicit operator EmptyDateTime(DateTime dateTime)
    {
        return new EmptyDateTime(dateTime);
    }

public static EmptyDateTime Empty
    {
        get
        {
            return new EmptyDateTime(DateTime.MinValue);
        }
    }
}

For those who are interested in the actual post:http://blogs.msdn.com/ericgu/archive/2004/03/23/95011.aspx

Using Parse

public bool IsNumeric(string s)
{
      try
      {
            Int32.Parse(s);
      }
      catch
      {
            return false;
      }
      return true;
} 

Using char 

internal static bool IsNumeric(string numberString)
{
    foreach (char c in numberString)
   {
        if (!char.IsNumber(c))
             return false;
   }
   return true;
}

Using Regex

static bool IsNumeric(string inputString)
{
    return Regex.IsMatch(inputString, "^[0-9]+$");
}

If you are using C# 2.0, you may use TryParse Method

public static bool IsNumeric(object Expression)
{
    bool isNum;
   double retNum;
   isNum = Double.TryParse(Convert.ToString(Expression),   System.Globalization.NumberStyles.Any,System.Globalization.NumberFormatInfo.InvariantInfo, out retNum );
   return isNum;
} 

Hope you enjoy it.

Creating a HelloWorld WebService

1. Using Visual Web Developer Express, create a new ASP.NET Web Service by File -> New Web Site…. Let us give a name of HelloWorldWebService and click OK.

2. By default, it should have created all files that are required including HelloWorld Method already implemented in Service.cs file. Open the file Service.asmx and you will see just one line of code.

3. Select the solution in the Solution Explorer and in the Properties window, set Use dynamic ports to False. If you wish to change the Port number, you may change it now. For me, it is showing 3697.

4. Press Ctrl+F5. This should build the solution and deploy the webservice using local development IIS that comes along with the express edition.

If you select the HelloWorld link, it should allow you to test the web service by click the Invoke button. It should open a web browser window with result as given below.

<?xml version="1.0" encoding="utf-8" ?>

<string xmlns="http://tempuri.org/">Hello World</string>

Leave the IIS running. You should be having a small icon in your system tray indicating that. Now, let us look at how to write a client to use this Web Service.

Consuming the HelloWorld WebService

1. Start Visual C# Express Edition. Create a new Console Application. (You may use window application also as your client application.) Let us name it as HelloWorldWebServiceClient.

2. Now Add Web Reference… by right clicking on the References in Solution Explorer. Enter the url

http://localhost:3697/HelloWorldWebService/Service.asmx

It should display the available opertions, in our case, it is HelloWorld. Click Add Reference. This should add localhost under the Web References folder in Solution Explorer.

Note: Ensure that the right Port number is mentioned.

3. Open the Program.cs and add the following code in the Main method.

localhost.Service service = new localhost.Service();

Console.WriteLine("Message Received: {0}", service.HelloWorld());

4. Press Ctrl+F5. This should build the solution and a message like this should be displayed in your console.

Message Received: Hello World

That's it.

1. Using an interface

First an interface is created as given below.

interface ITransactionAware{

}

Then, the class implements the interface.

class ClassWithMarkerInterface : ITransactionAware{

}

Using reflection, class can be checked to whether it implements the interface or not. Based on that result, any required action can be taken.

ClassWithMarkerInterface clsInterface = new ClassWithMarkerInterface();

if (clsInterface is ITransactionAware){

//start transaction

}

2. Using an attribute

Instead of an interface, an attribute is used.

class TransactionAttribute : System.Attribute{

}

The class is then marked with the above attribute.

[Transaction]

class ClassWithAttributeMarker {

}

The code to check for attribute is little more verbose than using the interface.

ClassWithAttributeMarker clsAttribute = new ClassWithAttributeMarker();

if (clsAttribute.GetType().IsDefined(typeof(TransactionAttribute),false)){

//start transaction

}

 

As you can see, using an attribute is slower than the normal interface. Purists would argue that an attribute should be used, but if performance is your top criteria then interfaces are the way.