Pathum's Blog

Mapping data flows in Azure Data Factory

2023-03-01T23:07:00.002+05:30

Overview:

Data flows are one of the features inside the Azure Data Factory which allows data engineers to develop data transformation logic in a graphical approach without writing code. The resulting data flows can then be executed as activities within Azure Data Factory pipelines that use scaled-out Spark clusters. Your data flows will run on your own execution cluster for scaled-out data processing. ADF internally handles all the code translation, spark optimization and execution of transformation. Data flow activities can be operationalized via the existing Data Factory scheduling, control, flow, and monitoring capabilities.

There are two types of Data flows:

Mapping Data Flow
Wrangling Data Flow

We start our discussion with Mapping Data flows

Mapping Data Flow –

Mapping data flows are visually designed data transformations in Azure Data Factory.
When there is a situation like you need to perform transformations using two or more datasets then you use a Mapping data flow.
You can perform several transformations such as Filter, JOIN, Aggregate, Union, Lookup, Sort, etc using mapping data flows.
Mapping data flows can be executed within ADF pipelines using data flow activities.
Azure Data Factory handles the code transformation and execution of Mapping Data Flow behind the scenes.
Mapping Data Flows activity can be created individually or within an Azure Data Factory pipeline.

Steps to create a Mapping Data Flow:

Open the Azure Data Factory using the Azure portal, then click on Author & Monitor

Click on the Author button then click on Data flows option. By clicking on three dots select New data flow option.

Select Mapping Data Flow. Click

Steps to build transformation logic in the data flow canvas:

Once you create your Data Flow, you’ll be automatically sent to the data flow canvas.

Note: The assumption is that you are already aware of the basic building blocks of a data factory- like creating linked services, Pipelines, etc. Click Here

In the data flow canvas, add a source by clicking on the Add Source
Name your source. Click on New to create a new source dataset.

Choose Azure Blob Storage. Click

Choose DelimitedText. Click Continue.

Name your dataset. Let’s say empDataDataset. In the linked service dropdown choose Linked service if you have created before or you can click +New button to create new linked service.

Once you’re back at the dataset creation window choose your File path. As the CSV file has headers, check First row as header. Select From connection/store to import the header schema directly from the file in storage. Click OK when done.

To add a transformation, click on the + icon on the data source which is next to your source node on the data flow canvas as specified in the screenshot below.
You can see there are various transformations available in the data flow.

Overview of AI techniques

2023-02-13T16:37:00.004+05:30

Artificial Intelligence (AI) is the way of making computing hardware and software think intelligently, in similarity to the manner humans use natural intelligence.

What is Artificial Intelligence?

The range of tasks that computers are capable of performing has increased rapidly since they were first created. The power of computer systems has been enhanced by humans in terms of their many working domains, growing speed, and decreasing size over time.

Artificial intelligence is a subfield of computer science that aims to build machines or computers that are as intelligent as people.

According to “John McCarthy," known as the father of artificial intelligence, AI is “the science and engineering of making intelligent machines, especially intelligent computer programs."

Artificial intelligence is a technique for teaching a computer, a robot that is controlled by a computer, or a piece of software to think intelligently, much as intelligent people do.

It is possible to create intelligent software and systems by first studying how the human brain works, as well as how people learn, make decisions and collaborate when attempting to solve a problem.

If given enough information, machines are capable of doing human-like actions. Consequently, knowledge engineering is crucial to artificial intelligence. In order to perform knowledge engineering, the relationship between objects and properties must be established. The methods used in artificial intelligence are listed below.

Therefore, an AI technique is a type of method applied to this set of available knowledge that organizes and uses that set as efficiently as possible:

Easy modifiable to correct errors
Useful in many ways even it is incomplete or to some degree inaccurate
Understood and clear by its provider
Having a clear purpose

1. Machine Learning (ML)

Applications that learn from experience and increase their prediction or decision-making accuracy over time are the focus of machine learning.

A subset of machine learning called "Deep Learning" uses artificial neural networks for predictive analysis. Machine learning uses a variety of algorithms, including reinforcement learning, supervised learning, and unsupervised learning. When learning unsupervised, the algorithm does not need classified data to make decisions on its own. In supervised learning, a function that includes a set of an input object and the intended output is inferred from the training data. Machines utilise reinforcement learning to determine the best possibility that needs to be considered and to take the appropriate actions to improve the reward.

2. Natural Language Processing (NLP)

Building machines that comprehend and react to text or voice data and answer with text or speech of their own in a manner akin to that of humans is the goal of natural language processing.

Computers are programmed to process natural languages in the context of interactions with human language. Natural Language Processing, which extracts meaning from human languages through machine learning, is a proven technique. In NLP, a machine records the audio of a person speaking. The dialogue is then transformed from audio to text, after which the text is processed to turn the data into audio. The machine then responds to people using audio.

Applications of NLP can be found in Interactive Voice Response (IVR) systems used in call centres, in language translators like Google Translate, and in word processors that check the correctness of syntax in text, like Microsoft Word.

However, due to the rules required in communicating using natural language, which are challenging for computers to understand, natural language processing is challenging due to the nature of human languages. In order to translate unstructured data from human languages into a format that the computer can understand, NLP employs algorithms to recognise and abstract the rules of natural languages. Additionally, NLP is used in content improvement tools such apps for paraphrasing, which enhance the readability of difficult text.

3. Automation and Robotics

Expert systems or applications that are able to perform tasks given by a human.

They have sensors to pick up information from the outside world, such as temperature, movement, sound, heat, pressure, and light, which is processed so they can act intelligently and learn from their mistakes.

The goal of automation is to have machines perform boring, repetitive jobs, increasing productivity and delivering more effective, efficient, and affordable results. In order to automate processes, many businesses use machine learning, neural networks, and graphs. By leveraging CAPTCHA technology, such automation can prevent fraud problems during online financial transactions. Robotic process automation is designed to carry out high volume, repetitive jobs while being flexible enough to adapt to changing conditions.

4. Machine Vision (MV)

Is the technology and procedures used to deliver imaging-based automatic inspection and analysis for applications like automatic inspection, process control, and robot guiding, typically in the industrial setting

Machines are capable of collecting and analysing visual data. In this case, cameras are utilised to record visual data, which is then processed using digital signal processing once the image is converted from analogue to digital. The data that is produced is then fed into a computer. Sensitivity—the ability of the machine to recognise weak impulses—and resolution—the extent to which it can distinguish between objects—are two essential components of machine vision. Machine vision is used in a variety of applications, including pattern recognition, medical picture analysis, and signature detection.

Introduction to Cloud Computing Windows® Azure™

2013-10-17T23:15:00.000+05:30

Wikipedia defines cloud computing as:

◦ “Internet-based computing, whereby shared resources, software and information are provided to computers and other devices on-demand, like the electricity grid.”

◦ The idea behind cloud computing is to access software applications and/or data from resources available through the Internet with a simple browser.

◦ In cloud computing, you pay for the resources (applications and data) you use, as you go.

Key reasons for shifting to cloud computing include cost savings, improved scalability and reliability, and availability of applications/data anywhere.

Why is it important

Companies incur a capital expenditure when spending money on a fixed asset like a data center or hardware.

Types of Cloud Computing Services

Windows Azure

Windows Azure is a cloud platform that enables you to quickly build, deploy and manage applications across a global network of Microsoft-managed datacenters.

Can integrate your public cloud applications with your existing IT environment.

Windows Azure delivers a 99.95% monthly SLA and enables you to build and run highly available applications without focusing on the infrastructure.

It provides automatic OS and service patching, built in network load balancing and resiliency to hardware failure.

You can use any language, framework, or tool to build applications. Features and services are exposed using open REST protocols. The Windows Azure client libraries are available for multiple programming languages, and are released under an open source license and hosted on GitHub.

Windows Azure Architecture

The hyper visor (Microsoft optimized Hyper-V ) runs on each server. It manages and controls the virtual servers running on the physical server.

Each virtual partition in the Microsoft cloud runs a modified version of Windows Server 2008 R2 Enterprise Edition.

Windows Azure cloud computing platform (PaaS).

Fabric Controller functions as the kernel of the Azure platform. It provisions, stores, delivers, monitors and commands the virtual machines (VMs) and physical servers that make up Azure.

AppFabric (formerly .NET Services) provides many enterprise-level services to include access control, caching and distributed messaging via a service bus.

Microsoft provides the hardware and software to host your applications, more formerly known as services, and data.

◦ Web site

◦ Computational service

You can access the data via an HTTP API from inside or outside the data centers.

You pay for the computational processing and storage in Windows Azure on a consumption model – that is in a pay as you go and for what you use manner.

Windows Azure Storage

Tables, blobs Storage, Queues & SQL Azure

You access Windows Azure Storage (any of the three types) through a REST API over HTTP.
Tables, blobs and queues storage types, allowing data to be stored in non-relational database.
structured tables similar to what you would find in a relational database, but without indexes and relationships

Binary Large Object (Blob) storage houses large binary data such as images, videos, music, documents

SQL Azure to support relational database needs

SQL Azure uses a special version of Microsoft SQL Server as its backend.

There are differences between SQL Azure and SQL Server 2008 there are number of limitations and unsupported features found in SQL Azure.

You access SQL Azure data with all the standard tools (Management Studio) and APIs that work with SQL server. (ADO.NET and ODBC APIs)

SQL Azure supports typical ACID transactions for work within the same database.

SQL Azure is more expensive than Windows Azure Storage, and in particular table storage.

SQL Azure Architecture

While SQL Azure is based on SQL Server, the architecture is such that you are not connecting directly to SQL Azure as you might connect to SQL Server.

Senior .NET Developer & Architect Skills List you must improve

2012-08-24T21:19:00.005+05:30

Programming

General Programming Skills (Data Types, Iteration, Functions)
Algorithm Proficiency
Unary/Binary Operation Proficiency
Declarative Programming Fundamentals
Regular Expression Familiarity
Framework Design Guideline Proficiency
Collection/Array Differences

Language Specific Skills

C# (or VB) Mastery
Enumerators
Delegates and Events
Nullable Types
Generics
Preprocessor Directives
P/Invoke Fundamentals
COM Interop Fundamentals
XML Documentation

CLR/Framework

CLI Fundamentals (Memory Management, Assembly Loading)
Framework Type Mapping (int -> Int32, long -> Int64)
IL Fundamentals
Framework Navigation Fundamentals
Reflection / Dynamic Invocation
Understanding of the 'Object' Type
Core Assemblies
Global Assembly Cache (GAC)
Boxing/Unboxing Fundamentals

ASP.NET

ASP.NET Concepts (CodeBehind, Compilation Model, Intrinsic Objects, ViewState, etc)
ASP.NET Control Proficiency
ASP.NET Page Life Cycle
ASP.NET HttpHandler, HttpHandlerFactory, and HttpModule Proficiency
Object-Oriented Nature of ASP.NET

Client-Side Development / General Web Development

JavaScript Proficiency (Closures, Anonymous Calls, etc)
CSS Proficiency (Specificity, Selectors, Rules, etc)
DOM Familiarity
XHTML Mastery (and it's relation to HTML)
Web Standards Familiarity
MOS (Mozilla, Opera, Safari) and IE Development Differences
Firefox Utilities (Firebug, Web Developer Toolbar)
Core Ajax & JQuery Fundamentals
Classic Web Development Concepts (State Management, Stateless Development)
WPF
Silverlight

.NET Data

ADO.NET Fundamentals (DataTable, DataSet, DataColumn, etc)
LINQ
Entity Framework
Data Binding Fundamentals
XML Serialization

.NET Concepts

Assemblies
Exception Handling
Streaming
Attributes
Versioning
Strong Naming
Disposable Resources (and IDisposable)

Object-Oriented Principles

OOP Principles (Inheritance, Polymorphism, Encapsulation) Proficiency
OOD GRASP Patterns Mastery
OOD GoF Pattern Fundamentals
UML Fundamentals

Enterprise Architecture

N-Tier Architectural Design
Service Oriented Architecture Fundamentals
Component Oriented Development Fundamentals
Enterprise Services/COM Fundamentals
MSMQ Fundamentals
Web Service/WS-* Fundamentals
RSS/Atom Fundamentals
WCF Fundamentals (Address, Binding, Contract)

Data

Set Theory Fundamentals
Database Design/Data Modeling Mastery
ACID and Normalization Concepts
SQL Server 2005/2008 Interaction Familiarity
SQL Server 2005/2008 Query Optimization
SQL Server 2005/2008 Index Design
SQL Server 2005/2008 Tuning
T-SQL Proficiency
O/R Mapper Familiarity
XML/DTD/XSD/XSLT/XPath Fundamentals

System Technologies

Windows Server 2003/2008 Familiarity
IIS 6.0/7.0/7.5 Proficiency
Component Services (COM+) Familiarity (the tool)
TCP/IP Fundamentals (Basic IP Theory, DNS, ping, tracert)
Networking Fundamentals (Routers, Switches, DHCP Servers)
Web Server Farm Fundamentals
'Run' Window Proficiency
Batch File Fundamentals
Windows Client Proficiency (Network Mapping, File Operations)

General Software Development

Software Development Life Cycle Fundamentals
Iterative/Agile/Waterfall/MSF Familiarization
Version Control Familiarity (CVS, Subversion, etc)

Quality Assurance

NUnit Familiarity
Unit/Regression Testing Familiarity
Profiling Fundamentals

General

College Algebra Proficiency
Statistics Fundamentals (probabilities mainly)
Calculus Theory Fundamentals (rates of change fundamentals)
Cryptography Fundamentals (asymmetrical, hash, checksum)
Proper English Grammar (who vs. whom, etc)
Solid Spelling Skills

Attitude

Results Focused Attitude
Vision Oriented (mainly for Architects and Team Leads)
Paradigm Shifting Abilities
Unlearning Abilities (the ability to unlearn obsolete paradigms)
High Standards ("takes pride in his or her work")
Unbiased to Vendors (i.e. doesn't say Microsoft SUCKS! or Linux blows!)

Ethics

Patience for Technology and Other People
Strong Ethical Nature (Honest, Trustworthy)
Common Sense Sexual Harassment Law Adherence (a.k.a. maturity)
Common Sense Use of Proper Language In and Around the Work Place (a.k.a. maturity)
Common Sense Politics/Religious Respect
Work Place Software Piracy Law Adherence
Gender Neutral Language Guideline Adherence (mainly in documentation and professional correspondence)

Delegates in C#

2011-12-01T01:58:00.001+05:30

Delegates is a type that reference Method. When it assigned by a method it behaves exactly same as that method. It can be used as parameters and can be returned a value. So it has same what are the methods have.

Delegates makes is possible to programmatically change method calls, and plug new codes in to existing classes. For these you need to know what are the method matches delegate’s signature and its return type. Delegates are similar to C++ function pointers but delegates type safe and Object Oriented. Methods don’t need to match the delegate signature exactly.

What is Covariance and Contravariance in Delegates ?

Covariance and Contravariance provides kind of flexibility when matching the method signature with delegate type that is defined.

Covariance permits a method to have a more derived return type than what is defined when the delegate define. Contravariance permits a method to have less derived parameter types than in the delegate type.

A delegate is a type it encapsulates a method see below example:

// Define the Delegate

public delegate void TestDelegate(string Message);

// Creating a method with string argument

public static void DisplayMessage(string Message)

{

Console.WriteLine(Message);

Console.ReadKey();

}

static void Main(string[] args)

{

// Instantiate the delegate and encapsulates the method "DisplayMessage"

TestDelegate Test = DisplayMessage;

// call the delegate

Test("This is my delegate method");

}

This is very simple example but delegate can used in advance way rather this. The instantiated delegate is an object, it can be passed as parameter, or assign to a property. When a delegate is use in this way the code using by the delegate does not need any knowledge of the method being used. This is similar functionality provide by interface encapsulation.

What is Multicasting?

In a delegate you can have more than one method to invoke, you can assign method to a delegate using “=” and you can add method to a delegate where it has assigned a method to invoke by using “+” if you want you can remove assigned method from a delegate where it has more methods to invoke by using “-“. This is called as multicasting.

Multicasting example:

namespace Delegates_Test2

{

delegate void Del();

class Simple

{

public void MethodA()

{

System.Console.WriteLine("Message from the method A.");

}

static public void MethodB()

{

System.Console.WriteLine("Message from the method B.");

}

namespace Delegates_Test2

{

class Program

{

static void Main(string[] args)

{

Simple sc = new Simple();

// Map delegate to the method: A

Del d = sc.MethodA;

// Map method: B with multicasting

d += Simple.MethodB;

d(); // Both methods are excute here

Console.ReadKey();

}

Generic Delegates

The delegate can define its own generic type parameters.

How to define:

public delegate void MyDelegate<T>(T item);

Generic delegate example:

namespace Generic_Delegate

{

//Generic Delegate define here with return value of T, and both T arguments

public delegate T Calculator<T> (T arg1, T arg2);

class MathUtility

{

// Generic method to execute with Two generic argument values and one generic methods

public static void Calculate<T>(T[] values1, T[] values2, Calculator<T> t)

{

for (int i=0; i < values1.Length; i++)

{ // execute the T method with two of T arguments

values1[i] = t(values1[i],values2[i]);

//And assigning results to First parameter

}

namespace Generic_Delegate

{

class Program

{

// My method to find square value

static int FindSquareValue(int x, int y)

{

// Your method's implementation

return (x * y); // Your method have defined to return the results

}

// My Method to find dividence with first value by second value

static double FindDividence(double a, double b)

{

// Your method's implementation

return (a / b); // Your method have defined to return the results

}

static void Main(string[] args)

{

// To get Square

int[] height = { 10, 5, 8 };

int[] width = { 4, 3, 6 };

MathUtility.Calculate(height, width, FindSquareValue); // Dynamically hook with

// FindSquare method

// You're only passing the both values and method

Console.WriteLine("Display Square Values...");

foreach (int i in height)

{

Console.WriteLine(i.ToString());

}

// To get Dividence

double[] Val1 = { 10, 80, 60 };

double[] val2 = {8,3,4};

MathUtility.Calculate(Val1, val2, FindDividence);

Console.WriteLine("Display Dividence values...");

foreach (double d in Val1)

{

Console.WriteLine(d.ToString());

}

Console.ReadKey();

}

Hope this documentation may valuable for you!!

how to reboot a stuck iPhone ( iPhone 4S, iPhone 4, iPhone 3GS, iPhone 3G, Original iPhone)

2011-11-16T02:35:00.001+05:30

Instructions on how to reboot a stuck iPhone

(This process can apply for iPhone 4S, iPhone 4, iPhone 3GS, iPhone 3G, Original iPhone)

iOS 5 is facing problem with updating after been updated to iOS 5, iPhone is stuck in recovery mode (Apple logo & black screen repeat repeatedly).

You can reset it in normal way of how when the iPhone crashes or locks up that prevents the iPhone from responding to being turned off.

Step 1.

Reset the iPhone by holding the sleep/wake button at the top right of the device and the home button at the bottom center of the face at the same time.

Step 2.

Hold them both until you see the screen go black. (if you have connected to any PC remove the connection first).

Step 3.

Wait until the white Apple logo appears.

Step 4.

When this happens, you can let go - the iPhone is rebooting.

An iPhone reset will not normally remove or delete any data or settings. However, the term reset is also sometimes used to mean deleting all content from it.

Any way you can start the iPhone with factor settings as new iPhone with connecting to iTunes. But if you have made your iPhone iCloud back up or iTunes backup of your Phone simply you can restore it.

Crystal report 2008 Redistribution Package

2011-11-14T19:57:00.001+05:30

I faced a problem when I’m deploying new application developed with Visual Studio 2010 and Crystal Report 2008.

Error Message:

Could not
load file or assembly 'CrystalDecisions.CrystalReports.Engine,
Version=13.0.2000.0, Culture=neutral, PublicKeyToken=692fbea5521e1304' or one
of its dependencies. The system cannot find the file specified.

But I have installed Crystal report 2008 on client’s PC.

Solution,

There is a redistribution package used to install. It doesn’t require installing Crystal report 2008 and this redistribution package is free of license.

Follow these links to download the packages.

For 32 bit

http://downloads.businessobjects.com/akdlm/cr4vs2010/CRforVS_redist_install_32bit_13_0.zip

For 64 bit

http://downloads.businessobjects.com/akdlm/cr4vs2010/CRforVS_redist_install_64bit_13_0.zip

Transactions in ADO.Net ( TransactionScope Class )

2011-10-06T15:16:00.000+05:30

A transaction is a logical unit of a work. There are few ways in implementing transactions. Either you can implement it in your T-SQL Statements or inside of the program logic. There are two ways in implementing in the .net programming code you can use DbTransaction Object or TransactionScope.

I would implement here TransactionScope class.

It creates a standard transaction called a “local lightweight transaction” that is automatically promoted to a full-fledged distributed transaction if required. You can use even multiple connection objects if you have to update tables in two databases.

First have to import System.Transactions namespace.

public void CreateTransactionScope()

{

SqlCommand ObjCmd = new SqlCommand();

try

{

// TransactionScope object defined here

using (TransactionScope Scope = new TransactionScope())
{

// _ConnectionString is the Class globally defined string value for the
database connection string

using (SqlConnection Sqlcon = new SqlConnection(_ConnectionString))

{

Sqlcon.Open(); // Opening the connection

// Assign Connection Object to SQLCommand Object

ObjCmd.Connection = Sqlcon;

//SQL Statement to execute

ObjCmd.CommandText = "INSERT INTO TBL_EMOPLOYEES VALUES('"+ "001"
+"', '"+ "Pathum Tiranga" +"','"+ "01/01/2011" +"')";

ObjCmd.CommandType = CommandType.Text;

//Execution happen here

ObjCmd.ExecuteNonQuery();

}

                    /* At the ending of the Scope of the Transaction Scope commiting the
                      transaction was done

                    If couldn't reach this statement all above datachanges happened to one
                      or more tables will be RolledBack

Scope.Complete();

}

/* If an exception is thrown within the TransactionScope object’s using block,

the transaction aborts, and all work is rolled back. */

catch (Exception ex)

{

throw ex;

}

When you create a TransactionScope object in a using block, the TransactionScope object assigns a transaction to this created connection, so you don’t need to add anything to your code to enlist this connection into the transaction.

Generic

2011-09-21T16:48:00.000+05:30

C# generics and C++ templates are very similar but they work differently. Generic exist to write code that is reusable across different types.

Let’s imagine we need a stack of integers if we didn’t have generic types, one solution is to hard code a separate version of a class for every required type “IntStack” but when we need stack of string have do the same way “StrStack”. This would cause considerable code duplication.

However this wouldn’t work aAnother solution would be write a stack that is generalizes by using Object as element type.s well hard coded “IntStack” & “StrStack” an “ObjectStack” require boxing & down casting that could not be checked at compile time.

int x = (int)stack.Pop(); // down casting

What we need is both a general implementation of a stack that works for all element type, and a way to easily specialize that stack to a specific element type for increased type safety and reduced boxing and casing.

Generics provide this by allowing parameterize element type. Stack<T> has the benefits of both “ObjectStack” and “IntStack”.

Test this example for further understanding.

class Part

{

private string _PartId;

private string _PartName;

private string _PartDescription;

private double _Weight;

public string PartId { get { return _PartId; } }

public Part(string PartId, string PartName, string PartDescription, double Weight)

{

_PartId = PartId;

_PartName = PartName;

_PartDescription = PartDescription;

_Weight = Weight;

}

public override string ToString()

{

return string.Format("Part Id: {0}, Part Name:{1}, Part Description:{2}, weight:{3}", _PartId, _PartName, _PartDescription, _Weight);

}

//the actual indexer, which accepts the generic type

//note the type must be a class (not a value type)

class Indexer<T> where T:class

{

struct ItemStruct

{

public string Key;

public T value;

public ItemStruct(string key, T value)

{

this.Key = key;

this.value = value;

}

List<ItemStruct> _items = new List<ItemStruct>();

// T must be a class so that can return null if not found

public T Find(string key)

{

foreach (ItemStruct _ItemStruct in _items)

{

if (_ItemStruct.Key == key)

{

return _ItemStruct.value;

}

return null;

}

public void Add(string key, T value)

{

_items.Add(new ItemStruct(key, value));

}

// Programe to Test it

class Program

{

static void Main(string[] args)

{

Indexer<Part> indexer = new Indexer<Part>();

Part p1 = new Part("001", "Mother Board", "Intel Chip set Mother Board", 0.75);

Part p2 = new Part("002", "Processor", "Intel Core i5", 0.2);

indexer.Add(p1.PartId, p1);

indexer.Add(p2.PartId, p2);

Part p = indexer.Find("002");

Console.WriteLine(p.ToString());

Console.ReadKey();

}

Structs in C#

2011-09-20T15:02:00.000+05:30

Struct is very similar to a class but strcut is value type and class is reference type, .Net supports the value type and reference type unlike Java, in Java you can define only reference type. Strcuts may leads to good performance where it’s used properly.

Reference types instances allocating in the managed heap and are garbage collected when there are no further references. Value types are allocated in the stack and so allocated memory is reclaimed as soon as their scope ends. Using a value type instead reference type may result in fewer objects on the managed heap, which results less load to garbage collector (GC) and better performance.

Since for a value type, a compiler by default doesn’t generate a default constructor, struct doesn’t have parameter less constructor. And no finalizer, no virtual members and it derives only from System.ValuType, This System.ValueType may again derives from System.Object . But structs can implement interfaces, in C# all primitive data types are value type except System.String

However value types have their poor sides too, when passing around big struct costlier than a reference type.

An example of declaring constructors.

struct Point

{

private int x;

private int y;

public Point(int x, int y)

{

this.x = x;

this.y = y;

}

An example of calling struct constructors.

Point point1 = new Point();

Point point2 = new Point(1,3);

Crystal Report Problems solving with Visual Studio 2010

2011-09-14T20:10:00.000+05:30

CRVS2010 Beta - file not found error crdb_adoplus.dll

An error when running the product when have installed CR 2010.

"Could not load file or assembly 'file:///C:
Program Files
SAP BusinessObjects
SAP BusinessObjects Enterprise XI 4.0
win32_x86
dotnet1
crdb_adoplus.dll' or one of its dependencies.

Solution

Setting the useLegacyV2RuntimeActivationPolicy flag to True does "solve" the problem. However, that is a hack and not a true fix. In trying to create a purely .NET 4.0 application, the end user shouldn't have to add this flag to get an application to work. Hopefully someone at SAP will note this and fix it in the core Crystal Reports functionality before the final version for VS 2010 is released.

Add following section to your config file and it may resolve the issue.

</startup>

How to add Crystal Report for Visual Studio 2010

2011-07-31T19:20:00.000+05:30

Crystal Reports for Visual Studio 2010 will be released separately, instead of included with the product.

Follow this link to download Crystal report for Visual Studio 2010, http://www.businessobjects.com/jump/xi/crvs2010/us2_default.asp

Click this highlighted link, download and install.

After finishing the installation you will not see any tool in the tool box. Then go to the “Project Properties” (if you have open new project in C#.net or VB.net) and find the Target Framework, you would see it as .Net Framework 4 Client Profile change this to be .NET Framework 4

Change as .NET Framework 4

When you change to .NET Framework 4 confirm it by click Yes

Now you can see Crystal Report Viewer in Tool Box.