![IndexersProperties. An index is identified by it's signatureBut a property is identified it's nameAn indexer is always an instance member, but a property can be static also. An indexer is accessed through an element accessBut a property is through a member accessDelegateInterfaceDeclaring a delegate public delegate void ProcessBookDelegate(Book book);The specification defines a set of related methods that will be calledInstantiating a delegate bookDB.ProcessPaperbackBooks(new ProcessBookDelegate(PrintTitle));Extension Methods inside .NET 3.5 I have just come across Extension Methods inside the new .NET framework and I have to say that they are very cool. They allow you to extend most if not any type with custom functions which you specify. The rule is that you must make the class which defines these methods as static, and a little new syntax, then away you go.So for this example what I did was create an interface called IKnownStringValidator, this interface has a property and one method which accepts the target string to be validated.Hide Code [-] public interface IKnownStringValidator { string Pattern { get; } bool Execute(string s); }{..} Click Show Code I then created a class which inherits from this interface. The class is called UKPostCodeValidator, and is simply so I can check for valid postcodes. Nothing too special here and certainly nothing new.Hide Code [-] public class UKPostCodeValidator : IKnownStringValidator { const string m_pattern = \"
[a-zA-Z]{1,2}[0-9]{1,2}[\\s]?[0-9]{1,2}[a-zA-Z]{1,2}\"
; #region IKnownStringValidator Members public string Pattern { get { return m_pattern; } } public bool Execute(string s) { System.Text.RegularExpressions.Regex r = new System.Text.RegularExpressions.Regex(m_pattern); return r.Match(s).Success; } #endregion }{..} Click Show Code OK, so now for the extension method. I have called the class StringHelpers and of course this is a static class, and also any method which you define also must be static. Notice the first argument of the class, it is the syntax to reference the calling instance of that specified type. You can then reference this instance inside the function block by the named parameter.{..} Click Show Code {..} Click Show Code Calling a delegate processBook(b); Hide Code [-] public static class StringHelpers { public static bool ValidateString(this string s, IKnownStringValidator validator) { return validator.Execute(s); } }The implementation of this is where more new syntax and newly legalised code comes in.Hide Code [-] protected override void OnLoad(EventArgs e) { base.OnLoad(e); // The below variable b is set to true with the following statement bool b = \"
WN5 8TJ\"
.ValidateString(new UKPostCodeValidator()); }Delegate and EventsI have seen this used largely inside the MVC tutorials and examples where by developers are extending the HtmlHelper class. One thing I did was make a quick and dirty function which allowed me to add an accesskey to the outputted anchor link. I have not figured out the lambdas implementation yet so here is all I did.Hide Code [-] public static string ActionLinkWithAccessKey(this System.Web.Mvc.HtmlHelper helper, string text, string action, string controller, string accesskey) { string format = \"
{2}\"
; format = String.Format(format, \"
/\"
+controller + \"
/\"
+ action, accesskey, text); return format; }{..} Click Show Code With the implementation of this code being:public class MyClass{ public delegate void MyDelegate(string message); public event MyDelegate MyEvent; public void RaiseMyEvent(string msg) { if (MyEvent != null) MyEvent(msg); }}class Caller{ static void Main(string[] args) { MyClass myClass1 = new MyClass(); myClass1.MyEvent += new MyClass.MyDelegate(myClass1_MyEvent); myClass1.RaiseMyEvent(\"
Hiii\"
); } //this method called only by MyDelegate public static void myClass1_MyEvent(string message) { //do some thing to respond to the event here }}Hide Code [-] public class MyClass{ public delegate void MyDelegate(string message); public event MyDelegate MyEvent; public void RaiseMyEvent(string msg) { if (MyEvent != null) MyEvent(msg); }}class Caller{ static void Main(string[] args) { MyClass myClass1 = new MyClass(); myClass1.MyEvent += new MyClass.MyDelegate(myClass1_MyEvent); myClass1.RaiseMyEvent(\"
Hiii\"
); } //this method called only by MyDelegate public static void myClass1_MyEvent(string message) { //do some thing to respond to the event here }}public class MyClass{ public delegate void MyDelegate(string message); public event MyDelegate MyEvent; public void RaiseMyEvent(string msg) { if (MyEvent != null) MyEvent(msg); }}class Caller{ static void Main(string[] args) { MyClass myClass1 = new MyClass(); myClass1.MyEvent += new MyClass.MyDelegate(myClass1_MyEvent); myClass1.RaiseMyEvent(\"
Hiii\"
); } //this method called only by MyDelegate public static void myClass1_MyEvent(string message) { //do some thing to respond to the event here }}public class MyClass{ public delegate void MyDelegate(string message); public event MyDelegate MyEvent; public void RaiseMyEvent(string msg) { if (MyEvent != null) MyEvent(msg); }}class Caller{ static void Main(string[] args) { MyClass myClass1 = new MyClass(); myClass1.MyEvent += new MyClass.MyDelegate(myClass1_MyEvent); myClass1.RaiseMyEvent(\"
Hiii\"
); } //this method called only by MyDelegate public static void myClass1_MyEvent(string message) { //do some thing to respond to the event here }}Event Handlers in the .NET Framework return void and take two parameters.The first paramter is the source of the event; that is the publishing objectThe second parameter is an object derived from EventArgsEvents are properties of the class publishing the event. The keyword event controls how the event property is accessed by the subscribing classes.Abstract ClassesInterfaceSome are abstract ,some may concrete.All the methods are abstractAn abstract class can have abstract members as well non-abstract membersBut in an interface all the members are implicitly abstract and all the members of the interface must override to its derived class.Abstract classes can have protected members, static membersThe members of the interface are public with no implementationAbstract classes are intended to be used base class. An abstract class cannot be instantiatedA non-abstract class derived from an abstract class must include actual implementations of all inherited abstract methods and accessors. Abstract and sealed (class cannot be inherited) modifier can’t work together.InheritancePolymorphismA class can be extending existing class & inheriting it's properties(attributes & behaviours).Ability of an object to have more than one forms which is direct result of inheritancethe propety that allows the reuse of an existing class to build a new classRuntime time polymorphism is done using inheritance and virtual functions. Method overriding is called runtime polymorphism. It is also called late bindingCompile time polymorphism is method and operators overloading. It is also called early binding.InternalProtectedInternal defines the scope with in the assembly andprotected defines the scope to the derived(sub) class.Internal means methods and properties will be accessible toClasses in the AssemblyProtected means methods and properties will be accessible toclasses and in the derived assemblyStored procedureUser defined functionsUDF can be used in the SQL statements anywhere in the WHERE/HAVING/SELECT section where as Stored procedures cannot be. Scalar-valued function-returns a scalar value such as an integer or a timestamp. Can be used as column name in queries Inline function-can contain a single SELECT statementTable-valued function-can contain any number of statements that populate the table variable to be returned. They become handy when you need to return a set of rows, but you can't enclose the logic for getting this rowset in a single SELECT statement.Extension methodsExtension methods are defined as static methods but are called by using instance method syntax. Their first parameter specifies which type the method operates on, and the parameter is preceded by the this modifier. Extension methods are only in scope when you explicitly import the namespace into your source code with a using directive.namespace ExtensionMethods{ public static class MyExtensions { public static int WordCount(this String str) { return str.Split(new char[] { ' ', '.', '?' }, StringSplitOptions.RemoveEmptyEntries).Length; } } }using ExtensionMethods;string s = \"
Hello Extension Methods\"
;int i = s.WordCount();View stateControl stateA page developer can disable view state for the page or for an individual control for performance.control state cannot be disabled. Control state is designed for storing a control's essential data (such as a pager control's page number) that must be available on postback to enable the control to function even when view state has been disabled. By default, the ASP.NET page framework stores control state in the page in the same hidden element in which it stores view state. Even if view state is disabled, or when state is managed using Session, control state travels to the client and back to the server in the page. On postback, ASP.NET deserializes the contents of the hidden element and loads control state into each control that is registered for control state.Anonymous Types and Implicitly Typed Variablesvar dog = new { Breed = \"
Cocker Spaniel\"
, Coat = \"
black\"
, FerocityLevel = 1 };select top 10 cast(key as varchar)+ '(' + cast(count(key) as varchar) + ')' from TableNamegroup by keyWCFWEB SERVICEAddress --- Specifies the location of the service which will be like http://Myserver/MyService.Clients will use this location to communicate with our service. The development of web service with ASP.NET relies on defining data and relies on the XmlSerializer to transform data to or from a service.Key issues with XmlSerializer to serialize .NET types to XML Binding --- Specifies how the two paries will communicate in term of transport and encoding and protocols Only Public fields or Properties of .NET types can be translated into XML. Only the classes which implement IEnumerable interface.Contract --- Specifies the interface between client and the server.It's a simple interface with some attributeClasses that implement the IDictionary interface, such as Hash table can not be serialized.The WCF uses the DataContractAttribute and DataMemeberAttribute to translate .NET FW types in to XML.XMLSerialization does not indicate the which fields or properties of the type are serialized into XML where as DataCotratSerializer Explicitly shows the which fields or properties are serialized into XML.WCF Service can be hosted within IIS or WindowsActivationService.Compile the service type into a class library Copy the service file with an extension .SVC into a virtual directory and assembly into bin sub directory of the virtual directory. Copy the web.config file into the virtual directory. ASP.NET web services are compiled into a class library assembly and a service file with an extension .asmx will have the code for the service. The service file is copied into the root of the ASP.NET application and Assembly will be copied to the bin directory. The application is accessible using url of the service file.Clients for the ASP.NET Web services are generated using the command-line tool WSDL.EXE.WCF uses the ServiceMetadata tool(svcutil.exe) to generate the client for the service.In ASP.NET Web services, Unhandled exceptions are returned to the client as SOAP faults.In WCF Services, unhandled exceptions are not returned to clients as SOAP faults. A configuration setting is provided to have the unhandled exceptions returned to clients for the purpose of debugging.CursorAdvantagesDisadvantagesCan do row vise validation from a table performance is lessCan fetch row wise records from a table every single row you retrieve will hit the server as a Single select query so performance will be low.Consumes more resourcesEfficiency: The query optimizer automatically selects theappropriate query plan, so the developer does not need todesign a complex algorithm to access the required data.Adaptability: As data changes or indexes are added ordropped, the query optimizer automatically adapts itsbehavior by using alternative plans. the ResultSet is less than 50 or 100 records it is better to go for implicit cursors. If the result set is large then you should use explicit cursors. Otherwise it will put Burdon on CPU.Fewer errors: Instead of the developer handling data andalgorithms in the application, the SQL Server Compact 3.5Database Engine natively supports the required operations. 1.Failing to check the value of @@Fetch_Status 2.Improper indexes on the base tables in your results set orFETCH statement 3.Too many columns being dragged around in memory, which arenever referenced in the subsequent cursor operations(probably the result of legacy code) 4.WHERE clause that brings too many rows into the cursor,Which are subsequently filtered out by cursor logic?Service Oriented ArchitectureSOA defines the interface in terms of protocols and functionality. An endpoint is the entry point to such an SOA implementation.requires loose coupling of services with operating systems, and other technologies that underlie applicationsService encapsulation – Many web services are consolidated to be used under the SOA. Often such services were not planned to be under SOA. Service loose coupling – Services maintain a relationship that minimizes dependencies and only requires that they maintain an awareness of each other.Service contract – Services adhere to a communications agreement, as defined collectively by one or more service description documents.Service abstraction – Beyond what is described in the service contract, services hide logic from the outside world.Service reusability – Logic is divided into services with the intention of promoting reuse.](https://image.slidesharecdn.com/diifeerencesinc-12559585051212-phpapp01/85/Diifeerences-In-C-1-320.jpg)
Diifeerences In C#
- 1. IndexersProperties. An index is identified by it's signatureBut a property is identified it's nameAn indexer is always an instance member, but a property can be static also. An indexer is accessed through an element accessBut a property is through a member accessDelegateInterfaceDeclaring a delegate public delegate void ProcessBookDelegate(Book book);The specification defines a set of related methods that will be calledInstantiating a delegate bookDB.ProcessPaperbackBooks(new ProcessBookDelegate(PrintTitle));Extension Methods inside .NET 3.5 I have just come across Extension Methods inside the new .NET framework and I have to say that they are very cool. They allow you to extend most if not any type with custom functions which you specify. The rule is that you must make the class which defines these methods as static, and a little new syntax, then away you go.So for this example what I did was create an interface called IKnownStringValidator, this interface has a property and one method which accepts the target string to be validated.Hide Code [-] public interface IKnownStringValidator { string Pattern { get; } bool Execute(string s); }{..} Click Show Code I then created a class which inherits from this interface. The class is called UKPostCodeValidator, and is simply so I can check for valid postcodes. Nothing too special here and certainly nothing new.Hide Code [-] public class UKPostCodeValidator : IKnownStringValidator { const string m_pattern = \" [a-zA-Z]{1,2}[0-9]{1,2}[\\s]?[0-9]{1,2}[a-zA-Z]{1,2}\" ; #region IKnownStringValidator Members public string Pattern { get { return m_pattern; } } public bool Execute(string s) { System.Text.RegularExpressions.Regex r = new System.Text.RegularExpressions.Regex(m_pattern); return r.Match(s).Success; } #endregion }{..} Click Show Code OK, so now for the extension method. I have called the class StringHelpers and of course this is a static class, and also any method which you define also must be static. Notice the first argument of the class, it is the syntax to reference the calling instance of that specified type. You can then reference this instance inside the function block by the named parameter.{..} Click Show Code {..} Click Show Code Calling a delegate processBook(b); Hide Code [-] public static class StringHelpers { public static bool ValidateString(this string s, IKnownStringValidator validator) { return validator.Execute(s); } }The implementation of this is where more new syntax and newly legalised code comes in.Hide Code [-] protected override void OnLoad(EventArgs e) { base.OnLoad(e); // The below variable b is set to true with the following statement bool b = \" WN5 8TJ\" .ValidateString(new UKPostCodeValidator()); }Delegate and EventsI have seen this used largely inside the MVC tutorials and examples where by developers are extending the HtmlHelper class. One thing I did was make a quick and dirty function which allowed me to add an accesskey to the outputted anchor link. I have not figured out the lambdas implementation yet so here is all I did.Hide Code [-] public static string ActionLinkWithAccessKey(this System.Web.Mvc.HtmlHelper helper, string text, string action, string controller, string accesskey) { string format = \" {2}\" ; format = String.Format(format, \" /\" +controller + \" /\" + action, accesskey, text); return format; }{..} Click Show Code With the implementation of this code being:public class MyClass{ public delegate void MyDelegate(string message); public event MyDelegate MyEvent; public void RaiseMyEvent(string msg) { if (MyEvent != null) MyEvent(msg); }}class Caller{ static void Main(string[] args) { MyClass myClass1 = new MyClass(); myClass1.MyEvent += new MyClass.MyDelegate(myClass1_MyEvent); myClass1.RaiseMyEvent(\" Hiii\" ); } //this method called only by MyDelegate public static void myClass1_MyEvent(string message) { //do some thing to respond to the event here }}Hide Code [-] public class MyClass{ public delegate void MyDelegate(string message); public event MyDelegate MyEvent; public void RaiseMyEvent(string msg) { if (MyEvent != null) MyEvent(msg); }}class Caller{ static void Main(string[] args) { MyClass myClass1 = new MyClass(); myClass1.MyEvent += new MyClass.MyDelegate(myClass1_MyEvent); myClass1.RaiseMyEvent(\" Hiii\" ); } //this method called only by MyDelegate public static void myClass1_MyEvent(string message) { //do some thing to respond to the event here }}public class MyClass{ public delegate void MyDelegate(string message); public event MyDelegate MyEvent; public void RaiseMyEvent(string msg) { if (MyEvent != null) MyEvent(msg); }}class Caller{ static void Main(string[] args) { MyClass myClass1 = new MyClass(); myClass1.MyEvent += new MyClass.MyDelegate(myClass1_MyEvent); myClass1.RaiseMyEvent(\" Hiii\" ); } //this method called only by MyDelegate public static void myClass1_MyEvent(string message) { //do some thing to respond to the event here }}public class MyClass{ public delegate void MyDelegate(string message); public event MyDelegate MyEvent; public void RaiseMyEvent(string msg) { if (MyEvent != null) MyEvent(msg); }}class Caller{ static void Main(string[] args) { MyClass myClass1 = new MyClass(); myClass1.MyEvent += new MyClass.MyDelegate(myClass1_MyEvent); myClass1.RaiseMyEvent(\" Hiii\" ); } //this method called only by MyDelegate public static void myClass1_MyEvent(string message) { //do some thing to respond to the event here }}Event Handlers in the .NET Framework return void and take two parameters.The first paramter is the source of the event; that is the publishing objectThe second parameter is an object derived from EventArgsEvents are properties of the class publishing the event. The keyword event controls how the event property is accessed by the subscribing classes.Abstract ClassesInterfaceSome are abstract ,some may concrete.All the methods are abstractAn abstract class can have abstract members as well non-abstract membersBut in an interface all the members are implicitly abstract and all the members of the interface must override to its derived class.Abstract classes can have protected members, static membersThe members of the interface are public with no implementationAbstract classes are intended to be used base class. An abstract class cannot be instantiatedA non-abstract class derived from an abstract class must include actual implementations of all inherited abstract methods and accessors. Abstract and sealed (class cannot be inherited) modifier can’t work together.InheritancePolymorphismA class can be extending existing class & inheriting it's properties(attributes & behaviours).Ability of an object to have more than one forms which is direct result of inheritancethe propety that allows the reuse of an existing class to build a new classRuntime time polymorphism is done using inheritance and virtual functions. Method overriding is called runtime polymorphism. It is also called late bindingCompile time polymorphism is method and operators overloading. It is also called early binding.InternalProtectedInternal defines the scope with in the assembly andprotected defines the scope to the derived(sub) class.Internal means methods and properties will be accessible toClasses in the AssemblyProtected means methods and properties will be accessible toclasses and in the derived assemblyStored procedureUser defined functionsUDF can be used in the SQL statements anywhere in the WHERE/HAVING/SELECT section where as Stored procedures cannot be. Scalar-valued function-returns a scalar value such as an integer or a timestamp. Can be used as column name in queries Inline function-can contain a single SELECT statementTable-valued function-can contain any number of statements that populate the table variable to be returned. They become handy when you need to return a set of rows, but you can't enclose the logic for getting this rowset in a single SELECT statement.Extension methodsExtension methods are defined as static methods but are called by using instance method syntax. Their first parameter specifies which type the method operates on, and the parameter is preceded by the this modifier. Extension methods are only in scope when you explicitly import the namespace into your source code with a using directive.namespace ExtensionMethods{ public static class MyExtensions { public static int WordCount(this String str) { return str.Split(new char[] { ' ', '.', '?' }, StringSplitOptions.RemoveEmptyEntries).Length; } } }using ExtensionMethods;string s = \" Hello Extension Methods\" ;int i = s.WordCount();View stateControl stateA page developer can disable view state for the page or for an individual control for performance.control state cannot be disabled. Control state is designed for storing a control's essential data (such as a pager control's page number) that must be available on postback to enable the control to function even when view state has been disabled. By default, the ASP.NET page framework stores control state in the page in the same hidden element in which it stores view state. Even if view state is disabled, or when state is managed using Session, control state travels to the client and back to the server in the page. On postback, ASP.NET deserializes the contents of the hidden element and loads control state into each control that is registered for control state.Anonymous Types and Implicitly Typed Variablesvar dog = new { Breed = \" Cocker Spaniel\" , Coat = \" black\" , FerocityLevel = 1 };select top 10 cast(key as varchar)+ '(' + cast(count(key) as varchar) + ')' from TableNamegroup by keyWCFWEB SERVICEAddress --- Specifies the location of the service which will be like http://Myserver/MyService.Clients will use this location to communicate with our service. The development of web service with ASP.NET relies on defining data and relies on the XmlSerializer to transform data to or from a service.Key issues with XmlSerializer to serialize .NET types to XML Binding --- Specifies how the two paries will communicate in term of transport and encoding and protocols Only Public fields or Properties of .NET types can be translated into XML. Only the classes which implement IEnumerable interface.Contract --- Specifies the interface between client and the server.It's a simple interface with some attributeClasses that implement the IDictionary interface, such as Hash table can not be serialized.The WCF uses the DataContractAttribute and DataMemeberAttribute to translate .NET FW types in to XML.XMLSerialization does not indicate the which fields or properties of the type are serialized into XML where as DataCotratSerializer Explicitly shows the which fields or properties are serialized into XML.WCF Service can be hosted within IIS or WindowsActivationService.Compile the service type into a class library Copy the service file with an extension .SVC into a virtual directory and assembly into bin sub directory of the virtual directory. Copy the web.config file into the virtual directory. ASP.NET web services are compiled into a class library assembly and a service file with an extension .asmx will have the code for the service. The service file is copied into the root of the ASP.NET application and Assembly will be copied to the bin directory. The application is accessible using url of the service file.Clients for the ASP.NET Web services are generated using the command-line tool WSDL.EXE.WCF uses the ServiceMetadata tool(svcutil.exe) to generate the client for the service.In ASP.NET Web services, Unhandled exceptions are returned to the client as SOAP faults.In WCF Services, unhandled exceptions are not returned to clients as SOAP faults. A configuration setting is provided to have the unhandled exceptions returned to clients for the purpose of debugging.CursorAdvantagesDisadvantagesCan do row vise validation from a table performance is lessCan fetch row wise records from a table every single row you retrieve will hit the server as a Single select query so performance will be low.Consumes more resourcesEfficiency: The query optimizer automatically selects theappropriate query plan, so the developer does not need todesign a complex algorithm to access the required data.Adaptability: As data changes or indexes are added ordropped, the query optimizer automatically adapts itsbehavior by using alternative plans. the ResultSet is less than 50 or 100 records it is better to go for implicit cursors. If the result set is large then you should use explicit cursors. Otherwise it will put Burdon on CPU.Fewer errors: Instead of the developer handling data andalgorithms in the application, the SQL Server Compact 3.5Database Engine natively supports the required operations. 1.Failing to check the value of @@Fetch_Status 2.Improper indexes on the base tables in your results set orFETCH statement 3.Too many columns being dragged around in memory, which arenever referenced in the subsequent cursor operations(probably the result of legacy code) 4.WHERE clause that brings too many rows into the cursor,Which are subsequently filtered out by cursor logic?Service Oriented ArchitectureSOA defines the interface in terms of protocols and functionality. An endpoint is the entry point to such an SOA implementation.requires loose coupling of services with operating systems, and other technologies that underlie applicationsService encapsulation – Many web services are consolidated to be used under the SOA. Often such services were not planned to be under SOA. Service loose coupling – Services maintain a relationship that minimizes dependencies and only requires that they maintain an awareness of each other.Service contract – Services adhere to a communications agreement, as defined collectively by one or more service description documents.Service abstraction – Beyond what is described in the service contract, services hide logic from the outside world.Service reusability – Logic is divided into services with the intention of promoting reuse.