Registry Hacks to Make Your PC Faster

http://www.pcworld.in/how-to/6-registry-hacks-make-your-pc-faster

Latest way of debugging using Debugger Canvas

There is a latest way of debugging in VS please read this

How to Add Checkbox to Excel in office 2007

Here is a good link: http://www.ehow.com/how_6209662_create-check-box-excel-2007.html

Lazy in C#

If you want to initialize a class as lazy Initialization you can go with Lazy key word.

Lazy _expensive = new Lazy
(() => new Expensive(), true);

Note: If you pass true as parameter,it will be thread safe else as false, it will not be thread safe.

If for a single -thread or single ton class Lazy is best

If you want to return a query with Default if its Empty?

If you want to return a query with default value if it is empty you can go with DefaultIfEmpty

void Main()
{
Coder coder = new Coder("Jon");

List coderCollection = new List()
{
new Coder("Anish"),
new Coder("marokey"),
};

var result = coderCollection.Where(r => r.Name == "Pat").DefaultIfEmpty(coder);

}

// Define other methods and classes here
class Coder
{
public string Name;

public Coder(string Name)
{
this.Name = Name;
}
}

Order by with out Culture

If you want to do some operations without any culture you can do with the help of StringCompare.Ordinal or StringCompare.OrdinalIgnoreCase.

void Main()
{
string[] nonCulture = { "äax", "ääü", "äbü" };

IEnumerable orderNonCulture = nonCulture.OrderBy( r => r, StringComparer.Ordinal);

orderNonCulture.Dump();
}

Type Property in C#

If want to know type is IsArray or IsInterface you can go with Type Properties

Semaphore and SemaphoreSlim

If need to restrict number of thread, can go with Semaphore.

Here is the example

class TheClub // No door lists!
{
static SemaphoreSlim _sem = new SemaphoreSlim (3); // Capacity of 3
static void Main()
{
for (int i = 1; i <= 5; i++) new Thread (Enter).Start (i);
}
static void Enter (object id)
{
Console.WriteLine (id + " wants to enter");
_sem.Wait();
Console.WriteLine (id + " is in!"); // Only three threads
Thread.Sleep (1000 * (int) id); // can be here at
Console.WriteLine (id + " is leaving"); // a time.
_sem.Release();
}
}

SemaphoreSlim is introduced in .Net 4.0 and is much faster and simple

?? Operator used in Linq

Here is the Msdn link for ?? Operator

if need to order by a query which need to orderby column1 if not null, if null orderby column2

void Main()
{

List orderList= new List()
{
new Order(1, 4),
new Order(null,6),
new Order(2,5),
new Order(null,3),
};

var k = from p in orderList
orderby p.ID ?? p.Count
select p;
}


class Order
{
public int? ID{get;set;}
public int? Count{get;set;}


public Order(int? id,int? count)
{
ID =id;
Count =count;
}
}

A simple example to say the difference between Descendants vs Elements

Here is the XML









if use Descendants

XDocument xDoc = XDocument.Load(@"C:\Users\anishmarokey\Desktop\XMLFile1.xml");

var result = from book in xDoc.Descendants("Book")
select new
{
Title = book.Attribute("Title"),
Author = book.Attribute("Author")
};

if use Elements

XDocument xDoc = XDocument.Load(@"C:\Users\anishmarokey\Desktop\XMLFile1.xml");

var result = from book in xDoc.Elements("Titles").Elements("Book")
select new
{
Title = book.Attribute("Title"),
Author = book.Attribute("Author")
};

Sort a class Employee

Here is a simple example for sorting an Employee class

public class MainClassToSortEmployee
{
public enum SortDirection { Ascending, Decending }

public static List Sort1(ref List list,
Func sorter, SortDirection direction)
{
if (direction == SortDirection.Ascending)
return list = list.OrderBy(sorter).ToList();
else
return list = list.OrderByDescending(sorter).ToList();
}

static void Main()
{

}
}

public class Employee
{
public string FirstName { get; set; }
public string LastName { get; set; }
public DateTime dateTime { get; set; }

public Employee(string p, string p_2, DateTime dateTime)
{
this.FirstName = p;
this.LastName = p_2;
this.dateTime = dateTime;
}
}

next task is to convert it to a Generic Linq

Can we write Linq in .Net 2.0 ?

yes.

To Know more Read this

Concat vs Union in C#

List list1 = new List(){1,2,3};
List list2 = new List(){1,2,4};

var dummyConcat = list1.Concat(list2); // combine all values without distinct
var dummyUnion = list1.Union(list2);// combine all values with distinct

result for dummyConcat




result for dummyUnion

Convert IEnumerable to DataTable

Here is small example to convert IEnumerable to DataTable by using the keyword CopyToDataTable()

DataTable dt = new DataTable();

//Adding Columns and names
dt.Columns.Add("ID" ,typeof(int));
dt.Columns.Add("Name",typeof(string));
dt.Columns.Add("Rank",typeof(string));

//Adding Rows and values

dt.Rows.Add(1,"anish","First");
dt.Rows.Add(2,"marokey","First");
dt.Rows.Add(2,"varghese","Second");

//querying the result where ID is 2
IEnumerable result = from p in dt.AsEnumerable()
where p.Field("ID") == 2
select p;

// By using the keyword CopyToDataTable(.net 3.5 SP1 and above) converting the IEnumerable to DataTable
DataTable dtConvertedFromLinq = result.CopyToDataTable();

Why Field is required for DataTable Linq

Here is one good blog for the same Click here

E.g

DataTable dt = new DataTable();

//Adding Columns and names
dt.Columns.Add("ID" ,typeof(int));
dt.Columns.Add("Name",typeof(string));

//Adding Rows and values

dt.Rows.Add(1,"anish");
dt.Rows.Add(2,"marokey");
dt.Rows.Add(2,"varghese");

//querying the result where ID is 2
var result = from p in dt.AsEnumerable()
where p.Field("ID") == 2
select p.Field("Name");

Add Columns and Name to DataTable

Here is a simple example to add values to DataTable

DataTable dt = new DataTable();

//Adding Columns and names
dt.Columns.Add("ID" ,typeof(int));
dt.Columns.Add("Name",typeof(string));

//Adding Rows and values

dt.Rows.Add(1,"anish");
dt.Rows.Add(2,"marokey");

Some good APIs for PDF converter in .Net

Here is the some good APIs for PDF Converter

http://www.aspose.com/categories/.net-components/aspose.pdf-for-.net/default.aspx

http://sourceforge.net/projects/itextsharp/

what is the use of parms keyword in C#

here is the msdn link for params

E.g:

with params

void Main()
{
Method(1,2,3); // you can call it like this
}

static void Method(params int[] array)
{
for(int i=0;i < array.Length;i++)
{
Console.WriteLine(array[i]);
}
}


without params

void Main()
{

Method(1,2,3); // throws error
}

static void Method (int[] array)
{
for(int i=0;i < array.Length;i++)
{
Console.WriteLine(array[i]);
}
}

you have to do

void Main()
{
int[] i = {1,2,3};
Method(i);
}

static void Method (int[] array)
{
for(int i=0;i < array.Length;i++)
{
Console.WriteLine(array[i]);
}
}

why the entry point of C# should be static void Main()

here is a couple of links which says the answer properly

Msdn: http://msdn.microsoft.com/en-us/library/acy3edy3.aspx
SO:http://stackoverflow.com/questions/5954439/c-entry-point-function

why the method name should be Main()

The using System; directive references a namespace called System that is provided by the Common
Language Infrastructure (CLI) class library. This namespace contains the Console class referred to in
the Main method.

taken from ecma-international

Dynamic keyword in C#

if you want to set the variable at runtime go with dynamic
if you want to set the variable at compile time go with var

e.g in dynamic

void Main()
{
var k = exampleMethod("23");
Console.WriteLine(k);
}

public static dynamic exampleMethod(dynamic d)
{
dynamic local ="string";
int i =3;
if(d is string )
return local;
else
return i;
}

Tuple in C#

in .net 4.0 Tuple keyword is introduced, this is new to C# and old to sql, F# etc,

Mostly tuple is used to return multiple values with out using ref or out key word.

Public Tuple ReturnMultipleObjects()
{
Tuple multipleObjects = Tuple.Create("string",1, new TextBox());
return multipleObjects ;
}

Msdn Link: http://msdn.microsoft.com/en-us/library/system.tuple.aspx
So Question: http://stackoverflow.com/questions/5951808/c-defined-arrays
Code Project: http://www.codeproject.com/KB/cs/C_Sharp_4_Tuples.aspx

Hello World in Android using MONO

Here is a good article which helps to write a Hello World using MONO

http://mono-android.net/Tutorials/Hello_World

Event Based Async Pattern(EAP)

The event-based asynchronous pattern (EAP) provides a simple means by which classes can offer multithreading capability without consumers needing to explicitly start or manage threads.

E.g: BackgroundThread, WebClient in System.Net

yield vs return in C#

The yield keyword signals to the compiler that the method in which it appears is an iterator block.

• yield can be used to return partially.
• yield maintains the state of the object
  

Simple example

void Main()
{
foreach(int i in GetDivideByTwo())
{
Console.WriteLine(i);
}
}


static System.Collections.Generic.IEnumerable GetDivideByTwo()
{
for (int i = 0; i < 100; i++)
yield return i/2;
}


Here is couple of good links

http://stackoverflow.com/questions/410026/c-proper-use-of-yield-return

http://stackoverflow.com/questions/1088442/what-is-the-purpose-advantage-of-using-yield-return-iterators-in-c/1088452#1088452

http://stackoverflow.com/questions/3969963/when-not-to-use-yield-return/3970171#3970171

Why Visual Studio takeing too much time to attach a Process

The reason this is simple, when you are added many break points and attach the process in the Debugger, it will take too much time to load all the controls. so better remove all the breakpoints and attach, wont take much time

ASP.NET Patterns every developer should know

Here is a good link for Design patterns in Asp.Net

http://www.developerfusion.com/article/8307/aspnet-patterns-every-developer-should-know/

What are the DataColumn.Expression property and what are the errors can cause in DataColumn.Expression

http://msdn.microsoft.com/en-us/library/system.data.datacolumn.expression.aspx

Declare and Intiaize Dictionary in a single line

This is a way to initialize the Dictionary using Collection intializers , specify one or more element intializers when you initialize a collection class that implements IEnumerable

Dictionary dic = new Dictionary()
{
{"erer","er"},
{ "rrr","rr"}
};

MethodInvoker Delegate

If you want to invoke a method with void parameter list?

you can use MethodInvoker Delegate.

E.g

private void someMethod() {
    myOtherForm.Invoke(new MethodInvoker(delegate() {
        label1.Text ="Update Label";
    }));
}

Table Variables Vs Temp Table

What is the difference and use of Table Variable vs Temp Table. To know more read

http://odetocode.com/code/365.aspx

EnumerateDirectories in .Net 4.0

if you want to return Enumerable collection of file information you can use EnumerateFiles

DirectoryInfo DirInfo = new DirectoryInfo(@"\\dir");

IEnumerable = DirInfo.EnumerateFiles();

Here is the link for Files,Directories,File system information and Lines from a text file

MsdnLink: http://msdn.microsoft.com/en-us/library/dd997370.aspx

what is SQL Injection?

http://en.wikipedia.org/wiki/SQL_injection

use of Explicit interface implementation

Here is a good post for the use of Explicit interface implementation have a look

SO: http://stackoverflow.com/questions/5896209/solution-for-multiple-inheritance-with-opportunity-to-change-protection-lvl

System.Object.GetType vs System.Type.GetType

System.Object.GetType- Gets the Type of the current instance

http://msdn.microsoft.com/en-us/library/system.object.gettype.aspx

System.Type.GetType -Gets a Type object that represents the specified type

http://msdn.microsoft.com/en-us/library/system.type.gettype.aspx


SO Link: http://stackoverflow.com/questions/5895871/difference-between-system-object-gettype-and-system-type-gettype/5895985#5895985

How to Format date in DataPicker

calanderFrom.Format = DateTimePickerFormat.Short;
calanderFrom.CustomFormat = "dd MMM yyyy";

always give "dd/mm/yyyy

you have to do it in

calanderFrom.Format = DateTimePickerFormat.Custom

 calanderFrom.CustomFormat = "dd MMM yyyy";

Msdn Link
http://msdn.microsoft.com/en-us/library/h2ef6zxz.aspx
http://msdn.microsoft.com/en-us/library/aa236616(v=vs.60).aspx

SO Link
http://stackoverflow.com/questions/5893626/datepicker-is-not-picking-custom-date-format