MCPD Certification

The CurrencyManager class has the ability to keep track of the current position of data within an array, collection or table that is to be bound to a user interface.

The WindowsPrincipal class allows a user code to check the group membership of a current Windows user. The IsInRole() method of the WindowsPrincipal class is used to manage the role-based security.

The u format pattern represents the UniversalSortableDateTimePattern using the format for universal time display. The U format pattern represents the Full date and time (long date and long time) using universal time.

Use one of the overloaded Parse methods of the DateTime Structure to convert a string into its equivalent date and time. Use the InvariantCulture of the CultureInfo class to get the CultureInfo that is culture-independent (invariant).

NeutralCultures are associated with a language but are not specific to a country/region.

The AllowInnerWhite member of the DateTimeStyles enumeration is used to ignore the extra white-space characters in the middle of any string during parsing.

The Number member of NumberStyles is used to indicate that the AllowLeadingWhite, AllowTrailingWhite, AllowLeadingSign, AllowTrailingSign, AllowDecimalPoint, and AllowThousands styles are used.

The AllowThousands member of the NumberStyles enumeration is used to indicate that the numeric string can have group separators, for example, separating the hundreds from the thousands.

The DigitShapes enumeration is used to specify the culture-specific display of digits.

A solar calendar is a calendar whose dates indicate the position of the earth on its revolution around the sun.

Use the “dddd” format pattern to represent a full name of a day of the week as defined in the current DateTimeFormatInfo.DayNames property.

Use the “MMMM” format specifier to represent the full name of the month as defined in the current DateTimeFormatInfo.MonthNames property.

The four standard format strings are as follows:

• O (or o)
• R (or r)
• s
• u

The CultureInfo class is used to represent information about a specific culture including the language, the writing system, the calendar used, etc.

The InvariantCulture property of the CultureInfo class is culture-independent and is not associated with any specific country or region.

Develops an application for users who live in Australia and format pattern for positive currency values by implementing CurrencyPositivePattern property of the NumberFormatInfo class.

Gather regional information about customers in a particular country by implementing RegionInfo class.

The culture attribute of the globalization section is used to specify the default culture for processing incoming requests from an application.

The ResourceManager class provides access to culture-specific resources at runtime. It looks up culture-specific resources, provides resource fallback when a localized resource does not exist, and supports resource serialization.

Use the System.Threading.Thread.CurrentThread.CurrentCulture property to enable specific users to use the application.

The SmallCaptionFont property is used to get a font that is used to display text in the title bars of small windows such as tool window.

Use the FontFamily and Font classes to constructs a regular style Arial font with a size of 18 pixels.

To create a Graphics object, you can perform any of the following actions:

• Receive a reference to a Graphics object as a part of the PaintEventArgs of a control.
• Call the CreateGraphics method of a control to obtain a reference to a Graphics object.

Create a Graphics object from any object that inherits from the Image class.

Use the antialiasing with the graphics in an application by using the HighQuality and AntiAlias properties.

Use the DashStyle.Dash property to specify a line consisting of dashes.

Make application accessible to low vision users by using the AccessibleName property to the accessibility aids (accessibility aids are specialized programs and devices, such as the Braille bar that help the users with disabilities to use computers more effectively).

Use the license agreement to store contents in the Rich Text Format (RFT) file and add the file to a setup project and also enhance user interface using the license agreement policy.

The Bitmap class can be used to change the color of an image.

Implementing PaintEventArgs class and draw a line on a pictureBox control using the DrawLine() method.

The Brushes class contains static properties that allow a user to get a Brush object of different colors.

Use the Color class and display a given text with specified brush color on a window.

The Icon class contains nine constructors.

The LineJoin enumeration is used to specify how to join consecutive lines or curve segments.

The FillRectangles method of the SolidBrush class is used to fill the interior of a rectangle.

Display statistical date in graphical format and use a custom graphing control that does not support resizing and ensure that users cannot resize, minimize, or maximize Form.

The MinimumSize property of the Form class is used to get or set the minimum size up to which a form can be resized. The Size property of the Form class is used to get or set the size of a form.

The \u0020 character escape is used to match a Unicode character using hexadecimal numbers.

The * wildcard character is used to match the preceding character or sub expression zero or more times. For example, “te*” matches “te” and “test”. The “*” character is equivalent to “{0,}”.

The . wildcard character is used to match any single character except “\n”. To match any character including the “\n”, use a pattern such as “[\s\S]“.

The \G character is used to specify that the match must occur at the point where the previous match ended.

Create a StringBuilder object and initialize it with a given string and set capacity to 75. Use the AppendFormat method of the StringBuilder class to append a formatted string at the end of the StringBuilder object.

The Traditional member of the StringDigitSubstitute enumeration is used to specify substitution digits that correspond with the user’s native script or language.

Regular expressions are the most effective way to verify the format of the data that matches a phone number.

The carrot (^) character is used to specify that the match must begin at either the first character of a string or the last character of a line.

The \b character is used to specify that the match must occur on a boundary between \w (alphanumeric) and \W (nonalphanumeric) characters.

The UTF8Encoding, UnicodeEncoding, and UTF32Encoding classes are better suited for global applications. The ASCIIEncoding class supports only the Unicode character values between U+0000 and U+007F.

The AppendLine method is used to append the default line terminator or a specified string to the end of the StringBuilder object.

The Match method is used to search an input string for an occurrence of a regular expression and it will return the results as a single Match object.

The StringBuilder class represents dynamic or mutable strings of characters, it represents a string-like object whose value is changeable.

The four objects that can be used with a Graphics object are as follows:

• Pen
• Color
• Brush
• Font

The Substring() method of the String class retrieves substring from a given string.

The Component Services tool creates, configures, and maintains a COM+ application. This tool can be used to view the system events, manage the system services and the distributed transactions. This tool performs the four tasks.

The COM+ transaction attributes are as follows:

• Required
• RequiresNew
• Disabled
• Supported
• Not Supported

Use the Platform Invocation Service and COM Interop Service to provide interoperability with the unmanaged code.

In a SingleCall object, a new object is created whenever a message arrives. The new object then processes the message and returns an optional reply. Finally, the object created is discarded.

Assembly Registration (Regasm.exe) tool is used to read the metadata within an assembly. It also adds the necessary entries to the registry allowing a COM client to create .NET Framework classes. Once a class is registered using Regasm.exe, a COM client can use it as a COM component.

COM components can be used in applications by adding a reference to a type library.

Strong name is a name consisting of an assembly’s identity, public key, and digital signature. It includes the assembly’s name, version number, and other related information (if any).

Use the Visual Studio 2005 IDE and Tlbimp.exe tool to import a COM type library to the Microsoft .NET Framework.

Deploying an assembly on COM application to a client computer using the Assembly Registration Tool (Regasm.exe) and register the file on the client computer.

Deploy a Client and a component to a single folder on multiple client computer by using COM Type Libraries.

The assemblies that contain culture-neutral resources are referred to as satellite assemblies. These assemblies are used to deploy language-specific resources for an application.

Caspol.exe can be used to examine and modify Machine-level, User-level, and Enterprise-level code access security policies.

The MarshalByRefObject class allows access to objects across application domain boundaries in applications that support remoting.

The dumpbin.exe utility is a command-line tool used for viewing imports and exports. It allows users to view various details for a given unmanaged code.

The Type Library Importer (Tlbimp.exe) tool is used to convert the type definitions from a COM type library into equivalent definitions in a common language runtime assembly.

The IsCallerInRole method of the ContextUtil class determines whether the client is having the specific role or not.

Web references refer to XML Web services that are published on either a local intranet or the Internet.

The Regsvr32.exe tool is used to register or un-register dynamic-link libraries (DLLs) and ActiveX controls (OCX) in the Windows Registry.

The Strong Name (Sn.exe) tool is used to sign assemblies with strong names. It also provides signature generation, signature verification, and key management.

The Common Language Runtime finds the assembly through the codebase setting. If no match is found in the location as specified in the codebase element in the application configuration file, the binding request fails. Then the CLR finds the assembly through probing.

The following are the different approaches on how the correct version of an assembly is specified in the assembly manifest:

1. Include the AssemblyVersion() attribute in an application’s source code.
2. Update the AssemblyVersion() attribute in the AssemblyInfo file of an application.
3. Include the System.Reflection namespace in the project when the AssemblyVersion() attribute is included in the application’s source code.

The Sn.exe tool is used to sign a portable executable file for a component or an assembly with an Authenticode digital signature.

Use a method in an application code and the method of the Assembly class to load and examine many assemblies having the same identity but located in different paths.

Use the following classes to construct email messages:

• Attachment
• MailAddress
• MailMessage

The WebResponse class derived from the System.Net namespace is used to provide a response from a Uniform Resource Identifier (URI).

The WebRequest class derived from the System.Net namespace is used to make a request to a Uniform Resource Identifier (URI).

The MailAddress class specifies the source and destination email address in two different objects.

Declarative security check is a security check performed on the declarative information in metadata. It uses attributes to place security information into the metadata of application code.

Imperative security check is a security check that occurs on calling a security method within the code being protected. It works by instantiating security classes and using them directly. It can be isolated within an object or method.

The utilities for the verification of the security policy for a deployed application are Caspol.exe, Preverify.exe, and Permview.exe.

Deploy an application to the client computers on a company’s intranet. Later, modify the assembly, any application that uses version 1.0 must now use version 2.0 by using PublisherPolicy.

Create an assembly that is consumed by other application and permission not granted to an assembly without minimum permission request.

Use the Code Access Security Policy tool (Caspol.exe) to enable users and administrators to modify the security policy for the machine policy level, the user policy level, and the enterprise policy level.

The Digital certificate is used to verify the identity of a potential customer.

Standard Internet e-mail is usually sent as plaintext over networks. This is not secure, as intruders can monitor mail servers and network traffic to obtain sensitive information.

L2TP with IPSec needs a certificate authority server (CA server) to generate certificates as well as to check their validity for providing secure communication.

Biometrics is a method of authentication that uses physical characteristics, such as fingerprints, scars, retinal patterns, and other forms of biophysical qualities to identify a user.

The Passport authentication provider is used for user authentication. It uses an encrypted mechanism to indicate authenticated users.

Use the following permissions to obtain minimum permissions to execute an application properly:

• Code Access Permissions
• Identity Permissions
• Role-Based Permissions

The ApplicationAccessControl attribute allows access checking at the component level in order to support component, interface, or method level role checks. The scope of the ApplicationAccessControl attribute is assembly.

The username and password attributes are specified in the element of the Web.config file for every request on a page.

The FullTrust permission set provides the best performance to set the permission sets. Use the authentication methods, which are provided by Internet Information Services (IIS) in an application.

Use the in the Web.config file to enable Custom authentication.

The Single Sign-On (SSO) is a system capability that enables users to access a number of applications without having to log on and/or provide a password to each application.

The SecurityAction.RequestMinimum value is used to request for the minimum permissions required for code to run.

The SecurityAction enumeration is used to specify the security actions that can be performed using declarative security.

Declarative security check is a security check performed on the declarative information in metadata.

In the Packet Privacy authentication level, authentication and encryption of data are performed. This level includes data integrity and the identity and signature of a user.

The authentication element in the Web.config file is added to identify users to view an application.

The SslStream.IsMutuallyAuthenticated property is used to get a boolean value that indicates whether both the server and client have been authenticated.

A Cryptosystem is a computer system that implements cryptography. It is used to secure email, digital signature, hash function, and key management.

The TripleDESCryptoServiceProvider class is used to encrypt data in a file as well as in the memory.

In cryptography, Optimal Asymmetric Encryption Padding (OAEP) is a padding scheme, which is often used with RSA encryption.

The RijndaelManaged class, which is a symmetric cryptography is used to encrypt assembly data.

CBC is the default mode for all encryption classes that uses Cipher Block Chaining (CBC) as the cipher mode.

The HashAlgorithmType enumeration is used to specify that the algorithm is used for generating Message Authentication Code (MAC) in Secure Sockets Layer (SSL) communications.

Certificate-based authentication is the most secure method of authentication. It provides a stronger key for encryption as compared to Digest authentication and sends encrypted passwords across the network. This prevents unauthorized users from intercepting passwords.

Secure Sockets Layer (SSL) is a protocol developed by Netscape for transmitting private documents via the Internet. Secure Sockets Layer (SSL) uses a combination of public key and symmetric encryption to provide communication privacy, authentication, and message integrity.

The IsSubSetOf method of the PrincipalPermission class is used to determine whether or not the current permission object is a subset of the specified permission object.

The PrincipalPermissionAttribute attribute applies to a class or method in order to declaratively demand for those users who belong to a specified role or have been authenticated.

The Union method of the PrincipalPermission class is used to create a permission object that is the union of the current permission object and a target parameter permission object.

Use the PrincipalPermission class to imperatively demand that the current user is a member of the local Users group.

Use either the System.Environment.UserName property or System.Environment.GetEnvironmentVariable() method to identify a username of a security context in which the current assembly is running.

The PermitOnly method of the FileIOPermission class is used to prevent callers higher in the call stack from using the code that calls a method to access resources that are not specified by the current instance.

The security policy levels in hierarchical order are Enterprise policy, Machine policy, User policy, and Application domain policy.

The Reset method of the PolicyLevel class is used to set the current policy level to the default state.

A publisher policy configuration file contains compatibility information issued by the publisher of a shared component.

Use the ZoneMembershipCondition class to test whether or not an assembly was located on the intranet.

Use the ApplicationDirectoryMembershipCondition to test whether the assembly was located in a specific folder.

The generic role-based security is used to secure data from unauthorized users.

Role-based authorization uses the GenericPrincipal class to represent the roles of the current user.

The Session object is used to create a variable that will be available as long as the session is active.

The Formatter class is used to provide base functionality for the common language runtime serialization formatters.

By default, a property or a field that returns an object or array of objects is automatically serialized.

The SerializableAttribute attribute specifies whether or not a class can be serialized. The Marshal-by-value objects are remotable objects that implement the ISerializable interface.

The Namespace property of the DataSet class is used to specify the namespace of a DataSet object.

The WriteXml method of the DataSet class is used to write XML schema and data from a DataSet object in XML format.

The Load method of the XmlDocument class is used to load the XML document in the memory stream.

The ImportNode method of the XmlDocument class is used to import the node from another XML document.

SoapFormatter is a simple, modular, extensible, and XML-based protocol. It is used to exchange messages between remoting applications.

RPC-Based Body Formatting is used to refer to the section 7 of the SOAP specification. In this formatting, all the parameters are contained within the single element in a SOAP message body.

The BinaryFormatter and SoapFormatter classes implement the IRemotingFormatter interface to support remote procedure calls (RPCs), and the IFormatter interface to support serialization of a graph of objects.

CDRom is used to specify that a drive is an optical disc device, such as a CD or DVD-ROM. Removable is used to specify that a drive is a removable storage device, such as a floppy drive or a USB flash drive.

The FileInfo class contains methods to create, delete, copy, and move files and properties related to a file.

Use the FileStream, MemoryStream, and StreamReader classes to perform the following operations:

• Read data from the byte stream
• Read data from the memory stream
• Read data from the file stream

The FileStream class is used to specify write, read, and other file-related operations either in synchronous or asynchronous manner.

The NegotiateStream class of the System.Net.Security namespace is used to provide a stream that uses the Negotiate security protocol for a client authentication and use the SslStream class of the System.Net.Security namespace to provide a stream that uses the Secure Socket Layer (SSL) security protocol to authenticate the server and optionally a client.

Use the Marshal class to allocate unmanaged memory, copy unmanaged memory blocks, and convert from managed to unmanaged types.

The StreamReader class is used to read characters from a byte stream. The StreamWriter class is used to write characters to a stream.

Use the Path class to get the file extension using the GetExtention() method and to change the file extension using the ChangeExtention() method.

Implement the Trace class to log any errors thrown by an application and direct the Trace output to a local log file.

The StreamReader class implements a TextReader that reads characters from a byte stream in a particular encoding. The System.IO.File.OpenText method creates a StreamReader that reads from an existing text file having the specified path.

When you inherit from the GZipStream class, you must override the three properties: CanSeek, CanWrite, and CanRead.

Use the following to perform the isolated storage tasks:

• The IsolatedStorageFile class
• The IsolatedStorageFileStream class
• The IsolatedStorageScope enumeration

The GZipStream class is used to provide methods and properties used to compress and decompress streams. It represents the GZip data format. This data format uses the same algorithm as the DeflateStream class, but can be extended to use other compression formats also.

The ApplicationScopedSettingAttribute class is used to specify that an application settings property has a common value for all users of an application. It cannot be inherited.

The ConfigurationManager class is used to provide access to configuration files for client applications.

There are three building blocks of .NET Framework, which are as follows:

1. Common Language Runtime (CLR)
2. Common Type System (CTS)
3. Common Language Specification(CLS)

The Process.Start method is used to start a Windows application and is registered in the system registry on a computer.

The Demand method is used to decide at runtime whether all callers in the call stack have been granted the permission specified by a current permission object by implementing class library.

An application configuration file is used to install it on a client computer along with an application and ensure that the settings in the application configuration file are applied.

The Account property is used to specify the security context of the Windows service application. In the Properties window of the Visual Studio .NET Component Designer, you can set the Account property to LocalService, LocalSystem, NetworkService, or User value.

Use the following properties to specify the individual settings for each service in a service database:

• DisplayName
• ServiceName
• ServicesDependOn
• StartType

The Publisher policy configuration file contains compatibility information issued by the publisher of a shared component. It ensures that the latest version of the shared component is used by all applications using the component.

The Global Assembly Cache (Gacutil.exe) tool is used to view and manipulate the contents of the global assembly cache. Microsoft Management Console (MMC) is a Windows utility designed to manage servers and services through a common user interface.

Publisher policy files contain compatibility information issued by the publisher of a shared component. These files ensure that the latest version of the shared component is used by all applications using the component.

The TypeLoadException exception is thrown when the common language runtime (CLR) is unable to find an assembly or the type within the assembly, or cannot load the type.

The Strong Name (Sn.exe) tool is used to sign assemblies with strong names. It also provides signature generation, signature verification, and key management.

For deploying shared assemblies, the binding policy that is a set of rules determines the place to search for the assembly and version to bind to the application. The searching process of the CLR involves the following three stages of the binding policy resolution:

1. Application policy resolution
2. Publisher policy resolution
3. Administrator policy resolution

The following are the steps that determine the correct version of an assembly:

1. The CLR examines the application configuration file.
2. It examines the publisher policy file.
3. It examines the machine configuration file.

Use components that provide services and resources and release the resources explicitly by the components using the Dispose method.

The Source property of the EventLog class is used to specify the source name to register and use when writing to the event log.

The CreateEventSource method of the EventLog class establishes an application as a valid event source for writing event information to a particular event log on a computer.

Develop an application to log important information of the application while it is executing and to write message text to the event log.

Perform an integration testing for an application and ensure that when the Write() method of the Debug class or the Trace class is called, each time only one entry is added to the event log.

The SystemException class throws an exception when an error occurs in an application using the Common Language Runtime (CLR).

The Process class can be used to print a word document with the help of the Print attribute.

The ProcessModule and ProcessModuleCollection classes can be used to get the complete information about modules used in a given application.

The Breakpoint is used to analyze variables, data records, and other settings in an application.

The Data Breakpoint is used during the execution of an application to change the value of the variables defined in the application.

The Runtime Debugger (Cordbg.exe) is a tool that provides command-line debugging services.

The Locals window is a debugging window and its contents change to reflect only the variables applicable to the current procedure. Global variables and variables in other projects are not accessible from the Locals window.

The Write method of the Debug class displays messages and writes variable values to the Output window, when an application is either stopped or paused.

The Immediate mode of the Command window is used for debugging .NET applications. This mode evaluates expressions, executes command statements, and prints values of variables defined in the application code.

The Print method of the Debug class can be used to display a message with a line terminator in the trace listeners collection.

Trace switch is an object that exists in the application code that allows filtering information. It allows enabling, disabling, and filtering of output in an application.

The Output debugging window is used to display status messages at runtime. Its content is cleared each time the application is compiled or run.

The Call Stack debugging window displays a list of currently active procedure calls during break mode.

A client-activated .NET Remoting object is created to ensure that an object logs error and warning messages to a log file and Windows application log.

The Watch window is used to see the values of variables within different scopes, i.e., module level, procedure level, and global variables.

The Assert method of the Trace class is used to check for a condition and displays a message if the condition is false.

The Cordbg.exe tool is used to debug the application from a command prompt. It provides command-line debugging services. It also helps to find and fix bugs in programs that target the .NET Framework common language runtime.

The Call Stack debugging window is used for viewing the list of currently active procedure calls.

The Log method of the Debugger class writes tracing and debugging messages that are displayed in the output window of the IDE.

Use the TraceSwitch class within a code and whenever the code uses Trace logging, it consults with the TraceSwitch level to verify whether or not to log information.

The Query property of the ManagementEventWatcher class is used to get or set the criteria to apply to events.

The Management class is used to represent a Common Information Model (CIM) management class. It is a WMI class such as Win32_LogicalDisk and Win32_Process.

Use the Unchanged member of the AuthenticationLevel enumeration to specify that the authentication level should remain the same as before.

The base keyword can be used when a subclass needs to refer to its immediate baseclass.

Write an event to the event log to allow a service to interact with users. The service does not require a logged-in user in order to execute and run under the context of any user including the system.

A service does not have a user interface or any visual output. Therefore, it can be easily run in the background to monitor an operating system without any user logging.

The Installutil tool is used to install a Windows application. The .NET class library provides some predefined installer classes that helps in application installation.

ClickOnce technology eliminates the difficulties in updating Windows-based applications, dependence of multiple application programs on shared components, and allowing permissions only to administrative users for application installations.

If a class derives from the ServiceBase class, the OnCustomCommand method is executed when the Service Control Manager (SCM) passes a custom command to the service.

When the CanHandlePowerEvent property is set to true, the power event command is passed to the service and then the OnPowerEvent method is called.

The ThreadPriority enumeration contains five priority members, which are a follows:

1. Lowest
2. BelowNormal
3. Normal
4. Highest
5. AboveNormal

The Join method is used to block the calling thread until a thread terminates.

The WaitSleepJoin state is used to specify that a thread is blocked.

Implement multiple threads using WaitCallBack delegate in an application.

Handle the DivideByZeroException using the try/catch block.

The Thread class of the System.Threading namespace is used to create a thread and execute it.

The Thread.IsBackground property is used to run a process in background. A thread is either a background thread or a foreground thread.

The System.Threading namespace is used to work with the Timer class and other classes related to the Timer class.

The Semaphore class is used to create a semaphore that can satisfy up to three concurrent requests.

The Mutex class is used to synchronize access to a protected resource.

The Sleep method is a static method and always acts on the currently running thread.

The Regsvcs.exe tool is used to load and register assemblies as well as generate, register, and install a type library into a COM application.

The Launch Condition tab in the Project Properties dialog box is used to specify conditions for installation. These conditions can be used in conjunction with a file, registry, or component search.

The File System editor can be used to add project outputs to a deployment project. It can be used to specify the location on the target computer where files are to be installed, and to create shortcuts on the target computer.

The Custom Actions editor is used to define custom actions that can execute code at the end of an installation process to perform actions, such as the installation of location-specific files, which cannot be handled during installation.

The User Interface editor allows a developer to change the visual screen that the a user sees while installing an application.

Type casting is the process of converting the value of a specific data type into another data type. There are two types of casting in .NET, i.e., implicit and explicit.

An array of data is declared by using a value data type with square braces and a variable name in which the array of data is to be stored.

The params keyword provides the facility to specify a method parameter that takes a variable number of arguments.

Boxing is an implicit conversion of a value type to a reference type. Unboxing is the inverse of boxing.

Variables that have only one copy per class are known as static variables. They are not attached to a particular instance of a class but rather belong to a class as a whole.

A value type is a variable that contains data values, which are stored in a memory storage area known as the stack.

The + operator concatenates two strings, and as a result, produces a new String object. It may also be used to concatenate a string with other data types.

The ToString(), GetType(), and Equals() methods are available in all the classes of .NET Framework.

The Short datatype is stored as a signed 16-bit (2-byte) integer ranging in value from -32,768 to 32,767. It is also stored as an unsigned 16-bit (2-byte) integer ranging value from 0 to 65,535.

Enumeration is used to provide symbols to a fixed set of related data values. Therefore, developers can use red, green, or blue, etc. instead of values such as 1, 2, or 3, etc.

A finally block is used to execute a certain portion of code that must be executed, irrespective of whether or not an exception is caught.

The unsafe keyword is used in case of pointers in C#. The unsafe keyword denotes an unsafe code or block, which is required for any operation involving pointers.

Each class is made up of properties, methods, and events. Property is a named attribute of an object. Properties define the characteristics of an object, such as name.

A constructor is used to create an object that is an instance of a class. It has the same name as the class in which it resides.

A destructor is a special type of method used to destroy instances of a class when they are no longer used by an application. A destructor has the same name as the class in which it resides, preceded by a tilde (~) symbol.

The .NET Framework provides the development and runtime environment for .NET applications. It is composed of several components that are required to build and run .NET-based applications.

Logical errors are those errors that appear in an application once it is in use. An application with logical errors compiles and executes correctly. However, it does not produce the desired result.

When declaring an array in Visual C# .NET, only the upper bound of the array is defined. Arrays in Visual C# .NET are always zero-based, i.e., the lower bound is always zero.

The common language runtime throws an exception when an error occurs during program execution resulting from a failed runtime check. This error is usually nonfatal and is recoverable by user programs.

A class is a reference type, and its object is created on the heap. On the other hand, a structure is a value type, and its object is created on the stack.

Use Pre and Post fix operators such as –, ++, etc to change the values of variables.

A user defined class that inherits abstract class and method.

An abstract method only has a semicolon after the method name and parenthetical argument list. The subclasses provide the body of the abstract method.

Use inheritance feature of .NET in an application and define an abstract class that contains a declaration of an abstract method.

Use the button click event to change the back color of the form according to the choice of a user without exception handling.

The StartPosition property of the form is used to display it at the center of the screen.

The Random class is used to change the back color of the form in random order whenever you click the button.

The Dock property is used to cover the complete form.

Add a ContextMenu control in an application and use the Show() method of the ContextMenu to display in the application.

A try block must be followed by a catch block or a finally block.

The SortedList and BitArray collections are accessed by an index.

The IComparer and IComparable interfaces are used to sort a collection using the Array.Sort method.

The following collections are available in both the System.Collections namespace and System.Collections.Generic namespace:

• Comparer
• SortedList
• Stack

The DictionaryEntry object is used to store entries in a Hashtable collection.

The IEnumerable and IDictionaryEnumerator interfaces are used to create a new collection type that must be iterated using a for each loop.

The IClassFactory interface deals with two issues: locality and language independence. It provides a language-neutral way to create a COM object by a client.

The AddRange method of the Control.ControlCollection class is used to add an array of controls to a collection. It is also used to add a single control to a collection.

The ArrayList class of the System.Collections namespace implements the IList interface by using an array of data.

It adds names to a SortedList object and retrieves the index number of a name.

It retrieves values to their corresponding keys stored in a Hashtable object.

The Dequeue method of the Queue class is used to retrieve as well as remove an item at the beginning of a queue.

The IsValid property of the CustomValidator control is used to indicate whether or not an input control passes validation.

The LinkedList class is a doubly linked list. It is created dynamically as per the requirements. It comprises a sequence of nodes; each node in the LinkedList Generic class contains a data field and one or two references pointing to the next and/or the previous node.

The LinkedList.Enumerator is used to read all the data of a generic LinkedList. The LinkedList Generic class is a doubly linked list. It is created dynamically as per the requirements. It comprises a sequence of nodes, each node in the LinkedList Generic class contains a data field and one or two references pointing to the next and/or the previous node.

If an application calls a large number of methods or large shared libraries at startup, using pre-compilation is the best technique to optimize the performance of the application during startup. Pre-compiling the application with Native Image Generator (Ngen.exe) reduces its startup time.

The CompareTo method of the IComparable generic interface returns a 32-bit signed integer value that indicates the relative order of the objects that is to be compared.

The StringDictionary class is used to store key and value pairs. When you create an instance of the specialized StringDictionary class, you can use only string indexes and set only values that are strings.

The BitVector32 structure is used to provide a simple structure that stores boolean values and small integers in a 32-bit of memory size.

If two strings are equivalent, the “==” returns true, also the “Equals()” method returns true. When you use “==” operator with the string class it compares value rather than the identity.

It manages collections and selects a class that is optimized for key-based item retrieval from both small and large collections using Hybrid Dictionary.

It is used to gather data from multiple email messages and format the data for display on the page and ensure that the page displays the data as quickly as possible.

An interface describes a group of related behaviors that can belong to a class or a struct.

Create a new collection type that must be sorted by using the Array.Sort and IComparer interface.

It converts the value of an object of an implementing type into a Common Language Runtime (CLR) type that has an equivalent value by using IConvertable interface.

Create a class that inherits from the EventArgs class to pass specialized information to an event handler apart from the source and event handler objects.

Multiple events can share the same delegate type. Once a delegate type is declared for an event, the event is declared as a delegate type field.

The StackTrace property is used to trace a stack at runtime. It is an ordered collection of one or more stack frames.

A custom event can invoke a delegate.

The PrintPageEventArgs class is used to provide data for the PrintPage event and it occurs when the output for the current page is needed.

The EditCommand event of the DataGrid control occurs when users click the Edit button for a DataGrid item. The EditItemIndex property of the DataGrid control specifies the index of an item in the DataGrid control to edit.

The TextBox event handler is used to execute when the TextChanged event of the TextBox is raised. The TextChanged event of the TextBox control occurs when the Text property value is changed.

When the TextChanged event of a TextBox control is fired, the text typed in one TextBox control will also appear in another TextBox control.