CLR and C#
1. Types of Authentication IIS.
A. Authentication
is the process which helps web server(IIS) to check and confirm the identity of
the client who request to access the website.
Types of
Authentication:
a. Http
Authentication: Basic Authentication, Digest Authentication
b. Integrated
Windows Authentication: NTLM(Network Lan Manager), Kerberos
c. Client
Certificates Access
d. Anonymous and
UnAuthenticated Access
e.
Logon-Redirection based: Form Authentication(IIS 7.0)
2. Types of Authentication and Authorization in ASP.Net.
A. Types of
Authentication: Windows Authentication, Forms Authentication
Types of
Authorization:- File Authorization and URL Authorization
3. ASP.Net Life cycle.
A. In ASP.Net,
the request starts with the client and processed through IIS. In IIS,
there are 2 utilities- INetInfo.exe and ASPNet_ISAPI.dll.
The InetInfo.exe
hosts the worker process and checks for the syntax and semantics of the
request, while ASPNet_ISAPI.dll is used to filter the .aspx files(based on the
extension). After the URL request split into 2 parts-
Virtual directory
name and Web Page name.
The worker
process which is nothing but the application factory basically contains all the
virtual directories and checks for the current virtual directory. If this is
first request, then there will be no Virtual directory available. Now the
worker process (W3wp.exe) creates a memory area called as AppDomain to check
for the current page. As AppDomain is the Page Handler factory so it contains
all the processes pages. If this is the new page then it will not find here.
The request further moves to the HttpPipeline where the actual execution of the
page happens by using the ProcessRequest method and creates the events(init,
load, render, unload) of the page. After creation of event and execution of all
the event, the HTML page returned back to the user.
4. ASP.Net Page Life Cycle.
A. There are few
events which gets generated during the page execution like: Page_BeginRequest,
Page_Init, Page_Load, Page_Prerender, Page_Render, Page_Unload etc
For the details
of the page life cycle, you can follow the previous question.
5. What are types: Value Type and Reference Type?
A. DataType
specifies Type of the data as well as Size of the data. There are 2 type of
DataTypes in C#:
a. Value Type:
Value type holds data directly, Value type stored in the stack memory, we can
get the direct value of the value types. Value type data type can’t be null.
b. Reference
types: This type does not hold the data directly. They hold the address on
which the actual data present. They stored in heap memory, Can have default
values.
We can make and
work with null reference type.
6. Boxing and Unboxing: Terminology, Advantages and Disadvantages.
A. Converting the
Value type data into the Reference type is called as Boxing.
byte b= 45;
Object o =
b.Tostring();
Converting the
Reference type data and keep its value to stack is called as the Unboxing.
Object o=10;
Int i=
Convert.ToInt32(o.ToString());
The Advantage of
boxing and unboxing is that we can convert one type of the object to another
type. The disadvantage is that it requires lot of memory and CPU cycles to
convert from one type to another type.
7. What is Type Safety?
A. TypeSafe is a
way through which the application or framework that the memory will not be
leaked to outside environment. E.g. C# is the type safe language where you must
have to assign any object before using it. In VB.Net it will take the default
value. So C# is the type safe language while VB.Net is not.
8. What is Strong Name?
A. Strong Name
(SN) is used to make the dll as the unique not by its name but by its version
as:
SN -k
fileName.dll
Now it will have
the unique name with respect to the version. This assembly when placed in the
GAC, it will treat as the unique with its version number and other details. 2
assemblies with the same name can exist in the GAC but both will have different
version. The CLR takes the latest version assembly while running the
application.
9. What are Extensions, modules and handlers?
A. HttpModule and
HttpHandler are the utilities which are used in the HttpPipeline under the
ASP.Net page life cycle. When the request received to Http Pipeline, the
HttpModule checks for the Authentication of the request and then it route the
request to the respective handler. After that HttpHandler takes that request
and process it. Once the request is processed through handler, again the
HttpModule takes the response and send it back to the worker process and
finally to the user.
10. What is worker process?
A. Worker process
(w3wp.exe) is an executable which is also called as the Application Factory.
This is used for the execution of the request and handling of the request for
the web pages.
11. CLR and DLR?
A. CLR (Common
Language Runtime) is the utility in the .Net framework to run the application.
It is the runtime engine which actually executes the application with many
responsibilities like taking care of memory management, versioning, CasPol etc.
DLR is new with
.Net 4.0 which is the Dynamic Language Runtime and used to run the application
on the fly wherever required. CLR runs as statically while DLR runs
dynamically.
12. In case more than one dll versions of an installable is installed, which version is invoked by default?
A. By default the
CLR will take and invoke the latest version of the dll and execute it
accordingly. There could be the same name assemblies exists in the GAC but they
will have different versions altogether for their uniqueness.
So while running
the application, CLR takes the latest version assembly and use in the
application.
13. What are Globalization and localization? How to implement them?
A. Globalization
is the concept of developing the application in more than one language while
the Localization is used for a particular language. Like if we develop the
application in more than one language we need to create the resource files
(.resx) by using System. Globalization and when we open the application in a
particular language, then the localizations used to convert that application to
the selected language.
14. What is assembly, GAC? Where they are physically located?
A. Assembly is
the collection of classes, namespaces, methods, properties which may be
developed in different language and packed as a dll. So we can say that dll is
also called as assembly.
There are 3 types
of assemblies-
- Private
Assembly, Shared Assembly, and Satellite Assembly.
GAC (Global
Assembly Cache)- When the assembly is required by more than one project
or application, we need to make the assembly with strong name and keep it in
GAC or in Assembly folder by installing the assembly with the GACUtil command.
To make the
assembly with strong name:
SN -k MyDll.dll
And to install it
in GAC:
GacUtil -i
MyDll.dll
GAC assemblies
are physically stored in Assembly folder in the system.
15. How to configure HTTPS for a web application?
A. To configure
the HTTPS (HTTP with Secure) for the web application, we need to have a client
certificate. The client certificates can be purchased from the trusted providers
and then we need to install that certificate for our site. By implementing the
HTTPS, all the data which is passing will be in encrypted format, while makes
the website more secure.
16. What are Inproc and Outproc in session? Where are session data stores in these cases?
A. Inproc and
Outproc is the types of Sessions where the session data can be stored in the
process memory of the application server(IIS) and in the separate state server.
When the session
data is stored in the process memory(AppDomain) of the server(IIS), the session
is called as the Inproc server. In this case when the server is restarted, the
session data will be lost. So In the Inproc session mode, the session data
stores in the memory object in AppDomain in Application Worker Process(AspNet_wp.exe)
When the session
data is stored in the separate server like in state server or in Sql Server,
the type of session is called as the Outproc session. In this case, if the
server where the application is running is restarted, the session will be still
remain in the separate servers.
So in the
inproc session state, the session data is stored in the Process memory of
the Server where the application is running.
In the Outproc
session state, the session data is stored in the separate server- may be state
server or in sql server.
17. When the View state is saved, and when is it loaded? How to enable/ disable View states?
A. View State
data is stored in the current page in base64 encoded format. It gets loaded
with the page and displays the values to the controls after the decoded.
Internally it actually saves the check-sum of all the control data where the
view state is enabled.so that when the page gets loaded due to any post back,
it again finds the check-sum and then decodes the Base64 encoded string and
gets back the same data to the controls. We can see the view state base64
encoded string in View Source of the page. It will be like
_VIEWETATE="DSDSDF8DGDGDFGFD5FDGGDJFF23BNN457M9UJOG" this.
View state won't
take the client or server memory to keep the view state data.
18. Difference between GET and POST. Which one is more secure?
A. GET and POST
methods are used for the data transfer between the web pages. GET mainly used
for small data which is not secure because in case of GET method, the data
which we are passing will be visible in the url so we can't keep the secure
data which will be visible in the url. There is also limited data which can be
passed in case of GET method (max 255 character).
POST is used for
transferring the huge data between the pages where we can keep the secure data
and can transfer it. In case of using the POST method, the data which is
transferring between the pages will not be visible so it is more secure than
the GET method. Also there is no limit for POST method to post the data to the
next page.
POST is more
secure.
19. What are Razor engine? How is it different from ASPX Engines?
A. Razor engine
is the new execution engine in the ASP.Net MVC 3 which is mainly used to
convert the rezor syntax views to HTML page in the MVC applications. It takes
the cshtml pages as the input for the ASP.Net MVC application and then render
to the HTML as the output. The ASPX engine takes the aspx code and then renders
to the HTML.
20. Pros and cons of JavaScript and AJAX.
A. JavaScript is
a scripting language and mainly used for client side validation. We can
validate the client side data before sending to the server. So by this we can
improve the performance of the application.
Ajax is
Asynchronous JavaScript and XML which is used for the Asynchronous calls to the
server. It uses the JavaScript/JQuery for making the call and use XML for the
Data Transfer. It basically uses the XmlHttpRequest for the asynchronous calls
to the server and communicates with the XML data which is platform independent.
So Ajax can be used with any technology.
21. In how many different ways JavaScript code can be used/called in an application?
A. JavaScript can
be used for Client Side validation, can also be used for calling of server side
methods and functions, can be used for calling the web services, WCF service,
Web API's, Calling the Controller and Action methods in ASP.Net MVC etc.
22. What needs to be done to call a JavaScript function from code behind?
A. If we want to
call the JavaScript function from the code behind, we need to attach the
JavaScript to the events in the page_load event as:
protected void
btnSave_cliekc9object sender, EventArgs e)
{
btnSave.Attributes.Add("onclick,"JavaScript:
retrun Validatedata();");
}
Here ValidateData
is the JavaScript function which can be used to validate the page data and if
validation fails, it will return and will not execute the server side
btnSave_click event.
23. Difference between Server Controls and User controls?
A. User controls
are used for the re-usability for the controls in the application. By using the
Web User Control template, we create the new user controls and then we can use
the same control in the various pages. User controls can be created by
combining more than one control to extend the functionality of the existing
controls. To use the user controls, first we need to register them in the web
page where we want to use that control. A separate copy is needed in each page
where we want to use the user control. User controls can't be included into the
toolbox.
Web Server
controls are those controls which can be found in the toolbox and can be
directly drag to the application like other controls textbox, button etc. For
the web server control, only 1 copy of the control is needed irrespective of
the number of web pages. If we want 10 text-boxes to be added in our web page,
we need only 1 copy of the textbox in the toolbox and can be dragged 10 times.
24. Difference between Var, object and Dynamic types.
A. var is the
keyword introduced with .Net 3.5 and used to store any kind of data like
data-set, data table, int, float, char etc. We can keep any kind of data into
the var variable.
var myVar = new
String[] {"hello", "world!!"} ;
Here the myVar is
the var type variable which is used to store the string array. Like this we can
store any type of data into the var.
Object is the
type which is used to store the objects of any kind. These objects need to be
type cast when used.
Like object
myObject = "Hello"
Here the myObject
variable of object type is used to keep the string variable. Now when we want
this variable value, we need to typecast it like
string strvar=
(string) myobject;
Var is the
compile time where the type of the var variable gets defined at the compilation
of the program. Once we define the type during compilation, we cant make the
changes of the type during run time or at the later stages.
Let's say, if we
define like
var myVar = new
String[] {"hello", "world!!"} ;
so here myVar
variable will be of string array. Now after this, I can;t make it like:
var myVar = 10 ;
If we do this, it
will throw error.
Dynamic- It’s a
keyword introduces with the .Net 4.0 and used to keep the data similar to the
var keyword. The type of Dynamic type can be changed even at run time.
So if we define
like:
dynamic myVar =
new String[] {"hello", "world!!"} ;
Then the myVar is
of type string array. Now if we do like:
dynamic myVar =
"Hello" ;
Now the myVar
type will be used as string type. So we can change the type in case of dynamic.
The difference
between the var and dynamic is that the dynamic variable uses the same memory
location to store the object and not changes throughout the application.
25. Difference between Functions and methods.
A. In.Net
terminology, both function and method are same. In general, we use method in
server side code of .Net but in scripting language we use function like
JavaScript function.
Here the
difference can be function always returns a value whereas method may or may
not. It depends upon the return type of the method.
26. Difference between Abstract classes and Interface. Explain with scenario where to implement one?
A. Abstract
Class: Collection of the Abstract (Incomplete) and Concrete (complete) members
is called as the Abstract class. If there is at least one abstract member in a
class, the class must be declared as abstract class.
When there is the
similar behavior, we can use the abstract class.
e.g. We want to
calculate the area of few shapes. As this is not generic to the application. We
have few shapes - like Circle, Ellipse, Parabola, Hyperbola, Triangle etc.
So we can create
an abstract class and implement it like below:
public abstract
class MyAbstractClass
{
// some
other concrete members
public
abstract void Area();// abstract method
}
Now in the child
class, let’s say i have a circle class and want to calculate the area of the
circle:
public class
Circle: MyAbstractClass
{
public
override void Area()
{
//
calculate the area of the circle
}
}
In the similar
fashion, we can calculate the area of other shapes.
Interface:
Collection of abstract members is called as the Interface. When the behavior is
not similar, we need to use the interface. All the members of the
interface
must be
overridden in the child classes.
e.g. Print
functionality of the application can have an interface method like:
interface Inf
{
void
Print();
}
Now as this is
the generic functionality and can be implemented in any of the class so we have
taken it as interface. We can implement this functionality into any page like:
class MyClass:
System.Web.UI.Page, Inf
{
public void
Print()
{
//
implement details about the Print method
}
// Here we can
implement any kind of print-like print to excel, xml, word all depends on the
our decision.
}
27. Different forms of Polymorphism. Differences between Abstraction and Polymorphism.
A. Polymorphism
is to use the same function in many forms. The polymorphism is of 2 types-
a. Classical
polymorphism (Overloading)
b. AdHoc
polymorphism (Overriding)
Polymorphism =
Poly(many) + Morphism(Forms)
Overloading: When
the runtime (CLR) find the behavior of class members at the compilation of the
program, it is called as the Classical polymorphism or Overloading. In this,
the method name is same but prototypes (method + parameters) are different and
it is implemented in the same class.
e.g.
public class
MyClass
{
public int
Add(int a, int b)
{
return a+b;
}
public int
Add(int a, int b, int c)
{
return a+b+c;
}
}
Overriding: When
the runtime (CLR) find the behavior of class members at the runtime of the
program, it is called as the AdHoc polymorphism or Overriding. In this, the
method name as well as the prototype (method + parameters) is same but they are
implemented in the different class. We use virtual keyword in the base class
method to override in the child class using the override keyword.
e.g.
public class
MyBaseClass
{
public
virtual void Show(string message)
{
Console.WriteLine(“Your message is : ”+ message);
}
}
public class
MyChildClass: MyBaseClass
{
public override
void Show(string message)
{
Console.WriteLine(“Your new message is : ”+ message);
}
}
Abstraction is
the behavior to get the required functionality. To implement the abstraction,
we use access specifiers where if we declare the members as private, it means
they will be available only to the current class and if we make them as public,
the other classes can also use them. So Abstraction is used to show only the
essential features It is also used to hide the unnecessary data which is not
relevant but present.
Abstract keyword
is also used to get the abstraction behavior. We can use Abstract Class and
Interface to implement Abstraction.
28. What are Delegates and Events?
A. A
Delegate is an object, which points to another method in the application. Delegate
holds- name of the method, arguments of the method (if any) and the return type
of the method.
See the below
points regarding the Delegate:-
·
delegate keyword is sealed type in System. Multicast
namespace.
·
Delegate works like a function pointer in C language.
·
Delegate holds the address of the function.
·
Delegate hides the actual information which is written
inside the method definition.
·
A delegate can hold address of a single function as well as
the address of multiple functions.
·
There are 2 types of delegate-
- Single cast delegate (hold single function)
and
- Multicast delegate(hold multiple functions).
·
Addition and subtraction are allowed for the delegates but
NOT multiplication and division. It means, we can add delegates, subtract
delegates etc.
e.g. To create a
single cast delegate, first we can create a class with a method as:
public class
DelegateDemo
{
public void
Show(string msg)
{
Console.WriteLine(msg);
}
}
Now we can call
the method Show using the delegate as:
public
delegate void MyDelegate(string message); //declare delegate
now we need to
create the object of the delegate with the address of the method as:
DelegateDemo obj
= new DelegateDemo();//class object
MyDelegate md=
new MyDelegate(obj.Show(“Hello World!!”));
md(); // call the
delegate
We can create the
events and event handler by using delegate with the below syntax:
public delegate
void textChangedEventHandler(Object sender, TextEventArgs e);
This event
handler will be used to handle the textbox textchanged event.
More details
about the delegate and events can be found at the below link:
http://msdn.microsoft.com/en-in/library/orm-9780596521066-01-17.aspx
29. Covariance and Contra-variance.
A.
covariance and contravariance are the new features added with the .Net
4.0. They are basically used for the implicit reference conversion for
different .Net types like array, delegate, and generic etc.
You can go to the
below link for more details with the examples that how we can use the
covariance and contrvariance to implicate reference conversion:
http://blogs.msdn.com/b/csharpfaq/archive/2010/02/16/covariance-and-contravariance-faq.aspx
30. What are Extension methods?
A. Extension
methods are special types of methods which are static methods but called as the
instance methods. The extension methods are added with the .Net framework
3.5 and with the Visual Studio 2008.
These methods
won’t affect the existing class and the label. These methods are used for the
extra behavior which the calls can provide. There is no need to build the class
again if we add any extension method to the class.
There are various
inbuilt methods added in .Net 3.5 with the introduction of LINQ. We can see the
extension methods like Order By when we use the Linq as:
e.g.
int[] numbers = {
10, 45, 15, 39, 21, 26 };
var
orderedNumbers = numbers.OrderBy(a => a);
31. What are Anonymous methods and Lambda Expression?
A.
Anonymous methods are those methods which does not have the name. As they
don’t have the name, so there is no way to call these methods. These methods
are created by using the delegate as below:
button1.Click +=
delegate{listBox1.Items.Add(textBox1.Text)};
Lambda
Expression: It’s an easy way to create anonymous functions. It is also an
anonymous function which has the capability to contain expressions and
statements. We can create the delegate and expression tree types using the
lambda expression.
For more details
regarding the anonymous method and lambda expression, we can go through the
below link:
http://www.codeproject.com/Articles/47887/C-Delegates-Anonymous-Methods-and-Lambda-Expression
32. Multithreading. How to implement Multithreading?
A. Executing more
than one processes simultaneously is called as multithreading. To implement the
multithreading concept, we need to use the System. Threading .dll assembly and
the System. Threading namespace.
To write the
thread program, we need to create a class with the method. Now we can create
the thread object and then pass the method by using the class object to the
method.
After that we
need to create the ThreadStart delegate which will call the actual method of
the class.
You can go
through below link for more explanation and other details regarding the
implementation and the code snippet:
33. Which interface is used to-
a. Convert
Boolean values to Visibility values?
b. Compare two
integer values?
c. Compare String
values?
A. Check the
below interfaces which are used in these scenarios:
a. Convert
Boolean values to Visibility values?
b. Compare two
integer values?- IComparable interface
c. Compare String
values? IComparer interface
SQL Server
34. What is the difference between a View and a Cursor?
A. View: It is
one of the database object which is also called as virtual table. We can also
say that it is a window through which we can see some part of database. View is
also called as stored query because we are going to fetch data using View.
View does not
contain any data. It’s just a virtual table which is used to get the records
from the base table for which the view is created. View is faster than ad hoc
queries because when we create the view and execute it once. Next time onwards
it will be available as the compiled format. So whenever the view is called, it
will just execute rather than compiling.
Cursor: Cursor is
a database object which is also the buffer area and created as a result of any
sql statement to hold the intermediate values.
Cursor is used to
format the rows individually. By using the cursor, we can process the
individual rows. There are 4 types of cursors in Sql Server-
a. Static Cursor
b. Dynamic Cursor
c. Key set cursor
d. Read-only
cursor
35. How to execute multiple update on different conditions in a single query?
A. To execute
multiple update using a single Sql update statement is the new feature
available with the SQL Server 2008. In this, we can update multiple rows using
a single update command.
36. Left outer joins and Right Outer joins
A. Joins are used
to retrieve data from more than 1 tables using some conditions. There are 3
types of outer joins in SQL Server database-
a. Left Outer
Join
b. Right Outer
Join
c. Full Join
In order to
extract the matched rows from both the tables and unmatched rows from the first
table, left Outer join is used. The syntax for left outer join condition is:
T1.Col1* =
T2.Col1
In order to
extract the matched rows from both the tables and unmatched rows from the
second table, right Outer join is used. The syntax for right outer join condition
is:
T1.Col1 =
*T2.Col1
In order to
extract the matched rows from both the tables and unmatched rows from the first
table and then unmatched row from the second table, full join is used. The
syntax for full join condition is:
T1.Col1* =
*T2.Col1
37. Exception handling.
A. Exception
Handling is the way to handle the unexpected error at runtime of the
application. From the SQL Server 2005 version, try…catch block is also
supported to catch the exceptions in SQL Server database. There is various
other ways to catch the error like using Global temporary variables @@Error,
inbuilt method RaiseError etc.
38. What is Performance Tuning? How do you implement it.
A. Performance
Tuning is the process through which we can optimize the SQL Server objects like
functions, triggers, stored procedure to achieve high response time to the
front end applications. In the performance tuning process we generally check
for the below point and optimize the objects processing:
a. Through
Query Execution plan, check for the processing time of the query execution.
b. Check the join
conditions and break all the condition for executions of the queries
individually.
c. Check for the
error prone process, conditions in the queries.
d. Check for the
loops whether they are terminated if any error occurs.
e. Check for the
processes which are taking more time in execution and how to reduce the
response time.
39. Difference between Having and Where clauses.
A. When the
'where' clause is not able to evaluate the condition which consists of group
functions, Having clause is used. Having clause is always followed by the Group
By clause.
'Where' clause is
used to filter the records based on the conditions. If there is the requirement
to get the group data in the select statement and where clause is not able to
get it, we can use the Having clause.
e.g. Display
DeptNo, No.of Employees in the department for all the departments where more
than 3 employees are working
SELECT DEPTNO,
COUNT(*) AS TOTAL_EMPLOYEE
FROM EMP
GROUP BY DEPTNO
HAVING COUNT(*) >3
40. Difference between Temp tables and Tables variables?
A. Temp Table in
SQL Server:
a. Temp table are
the special type of tables which are used to store the intermediate data of the
actual table.
b. Temp tables
are only visible to the current sessions of the sql server instance. When the
session end, these table data automatically drops.
c. We can’t join
the temp tables as they don’t allow the foreign key constraints.
d. Temp tables
are created in TempDB database.
e. We can use the
same temp table name for the different user sessions.
f. Mostly used in
stored procedure to handle the intermediate data.
41. What does @ and @@ suffixed by property names specify?
A. @- This is
used for the variable declaration
e.g. @name
varchar2(50)
@@- This is used
for the Global variable declaration
e.g. @@Error=0
42. Self-join queries.
A. Self-Join is a
type of join which is used to join the same table by creating the multiple
instances of the same table. So we can join 2 instances of the same table in case
of self-join. This type of join is used when there is the requirement to get
the referenced data which is available in the same table.
e.g. A table
contains EmpId, Ename and ManagerId
As the manager is
also an employee. Now if we want that who is the manager of which employee. In
this situation, we need to create the instance of the same table and get the
required data as:
SELECT EMPID,
ENAME, ENAME AS [MANAGER NAME]
FROM EMP E1, EMP
E2
WHERE E1.EMPID=
E2.MANAGERID
43. Types of Index.
A. Index is
one of the database objects which is used to improve the performance of the
database queries. It reduces the table scan while retrieving the data from the
database and the search gets fast-
There are 2 types
of indexes used in the SQL server:
a. Clustered index
b. Non clustered
index
There are 3 more
types of index but those comes under the above two-
a. Unique index
b. Composite
Index
c. XML
Index-added in SQL Server 2005
The index
basically works on searching like binary tree where the root value is the finding
value and it will be compared with the partitioned value of the tree.
44. Difference between Primary key, Unique key and Candidate key?
A. Primary Key-
It is a key to make the unique identification of the row in a table. It doesn't
allow null values in the primary key column. We can create the lookup columns
based on the primary key. One table allows maximum of 1 primary key and in 1
table, we can create the primary key column by using 16 columns. Due to one of
the normalization rule, we have to create primary key for the table to make the
rows unique.
Unique Key:-
(Primary Key + Not null) is called as unique key. Unique key is also used to
make the rows as unique in a table. The only difference between primary key and
unique key is that primary key does not allow null value while the unique key
allow. The limitation of the null in unique key is that it allows only one Null
value. So only in one row, we can make the key as null for the unique key.
Candidate key-
The key other than primary key, to make the rows as unique is called as
candidate key. In candidate key, we take the columns which are not in the
primary key and make the key for uniqueness of the row.
45. What is the default value for Datetime. What are Min and Max values for Date in 2008.
A. The
default value of Date is CURRENT_TIMESTAMP
Below are the new
date and time values in Sql Server 2008:
In SQL Server
2008:
1. DateTime2
Min Value:
0001-01-01 00:00:00.0000000
Max Value:
9999-12-31 23:59:59.9999999
2. Date
Min Value:
0001-01-01
Max Value:
9999-12-31
WCF
46. What is WCF also known as?
A. WCF
(Windows Communication Foundation) is also know as Indigo by its code
name.
47. Difference between WCF and Web Services?
A.
Below are the main differences between the WCF
and Web Service:
Web Service:
a. Can be hosted
in IIS only
b. Only two types
of operations affects- One-Way, Request-Response
c. To serialize
the data use System.Xml.Serialization
d. To encode the
data use- XML 1.0, MTOM, DIME, Custom
e. Web Service
can be accessed through HTTP channel.
WCF service:
a. Can be hosted
in IIS, Self Hosting, WAS, Windows Services etc
b. Three types of
operations affects- One-Way, Request-Response and Duplex
c. To serialize
the data use System.Runtimel.Serialization
d. To encode the
data use- XML 1.0, MTOM,Binary, Custom
e. WCF Service
can be accessed through HTTP, TCP, Named pipes, MSMQ,P2P etc.
48. What are Endpoints?
A. The collection
of Address, Binding and Contract is called as End Point. In Sort,
EndPoint = A+B+C
Address (Where)-
It means where the service is hosted. URL of the service shows the
address.
Binding (How)-
How to connect to the service, is defined by the Binding. It basically has the
definition of the communication channel to communicate to the WCF service
Contract (what)-
It means what the service contains for the client. What all the methods are
implemented in the WCF service is implemented in the Contract.
49. What are Behavior and Bindings?
A. Binding mainly
describes about the communication of the client and service. For this, there
are protocols corresponding to the binding behavior which will take care of the
communication channel. There are different protocols which we use for the
different types of bindings. E.g. HTTP, TCP, MSMQ, Named Pipes etc.
Behavior is used
for the common configurations that could be for endpoints. When we use the
common behavior, they affect to all the end points. Adding the service behavior
affect the service related stuff while the endpoint related behavior affects
the end points. Also operations level behavior affects the operations.
50. What are different types of Contracts supported?
A. There are
mainly 5 type of contracts used in WCF service:
a. Service
Contract
b. Operation
Contract
c. Data Contract
d. Message
Contract
e. Fault Contract
51. What is the difference between Transport and Message Security mode?
A. WCF supports 2
types of security- Transport Level Security and Message Level Security
Transport Level
Security- In this type of security, we make the transport channel as secure so
that the data flows in that channel will be automatically secured. For HTTP
channel, we use the client certificate for the security of the web address. SSL
is used for the HTTP channel security. As we don’t need to secure each of the
messages which are floating between the client and the service, the speed is
faster as direct message is going to the client from the service.
Message level
security- This type of security in WCF is used where we don't have the fixed
transport medium and we need to secure each message which is floating between
the server and the client. In this type of security we use certain algorithms
for making the message as secure message. We use some extra bits and send with
the message. We also use some encryption techniques like SHA1 or MD5 which make
the proper security for our message. As each message needs to be secured, this
type of security makes some delay in the process of sending and receiving the
messages.
52. How to configure WCF security to support Windows authentication?
A. To support the
WCF security in Windows Authentication, we need to add the ClientCredetialType
attribute to “Windows” under the security tab element:
transport
clientCredentialType="Windows"
53. How to use Fault Contract?
A. Fault
Contract is mainly used for viewing and displaying the errors which occurred in
the service. So it basically documents the error and the error message can be
shown to the user in the understandable way. We can’t use here the try….catch
block for the error handling because the try…catch is the technology specific
(.Net Technology). If we use the try...catch block for handling the errors, the
error will not be reached to the client who is consuming the service. Because
this error will not be included in the message. So we use the Fault contract
for the error handling.
e.g. To use the
Fault contract, we can simply write like the below:
public int
Add(int number1,int number2)
{
// write
some implementation
throw new
FaultException (“Error while adding data..”);
}
Here the fault Exception
method is the inbuilt method which will throw the exception and display the
message . We can use the custom class so that the message can be customized and
the customized message can be sent to the client.
So we can create
a clss like:
public Class
CustomException
{
public int
ID {get;set;}
public
string Message {get;set;}
public
string Type{get;set;}
}
Now this custom
type we can use with the Operation Contract as:
[ServiceContract]
public interface
IMyInterface
{
[OperationContract]
[FaultContract(typeOf(CustomException))]
int Add(int
num1,int num2);
}
Now while
implementation of the Add method, we can assign the class properties.
WPF
54. Diff between XML and XAML.
A. XAML is the
declarative XML based language which is used to define the objects and
properties. XAML document is loaded by XAML parser. So XAML Parser initiates
the objects and set those properties. XAML is mainly used in creating the
objects in WPF and Silverlight applications.
For more detailed
explanation, you can go through the below link:
http://www.differencebetween.net/technology/software-technology/difference-between-xml-and-xaml/
55. Stack Panel and Wrap Panel.
A. StackPanel is
one of layout control in WPF. We can place the child controls inside the
stackpanel either horizontally or vertically. So it provides two types of
orientations- Horizontal Orientation and Vertical orientation.
Wrap panel is another layout control which is similar to the StackPanel. Wrap panel not only keep the control in horizontal and vertical orientation but also wrap them into new line if there is no space. Here also the orientation can be set as Horizontal or Vertical. Its main use is to arrange the tabs in the tab control, menu control or in toolbar items.
56. Hierarchical Data Template.
A. Hierarchical
Data Template is a type of data template which is used to bind the controls
which supports HeaderedItemsControl, like TreeViewItem or MenuItem
We can bind those
controls items using the Hierarchical Data Template. It displayed the data into
Hierarchical structure in the tree structure. It could be in the left to right
or top to bottom.
You can go
through the below link for more details:
http://msdn.microsoft.com/en-us/library/system.windows.hierarchicaldatatemplate.aspx
57. Virtualization.
A. This is the
feature in WPF which increases the efficiency of the programs when there are
the large data objects. If the WPF ItemsControl is bound with the large
collection data source object and we enabled the virtualization, then the
controls will show only the data which is in the visual container for those
items which are visible currently. This visual data is only the small part of
the large data object. Now when the user will scroll down or up, the rest of
the data will be visible and previous data will be hidden again. So this is
increase the efficiency of the program from the UI prospective.
58. Events and Routed Events.
A. Routed
event is special type of event which can invoke and handle multiple events from
different objects rather than the event which is coming from one object. So it
generally handles the object from the element tree. So whatever the elements
inside the element tree and if they generate the event-may be multiple events,
the routed event is capable of handling those events.
The routed event
can be invoked in both the directions but in general it comes from the source
element and then bubbled up in the element tree until the root element.
59. Bubbling and Tunneling.
A. Bubbling: When
the events are raised form the innermost element in the visual tree and comes
up towards the root element, is called as bubbling.
Tunneling: It is
the opposite process of Bubbling where the events fired by the root element
goes down towards the last child element control.
60. Resource Dictionary, Static Resources and Dynamic Resources.
A. Static and
Dynamic resources are used for binding the resources to the control
objects.
The main
difference between StaticResource and DynamicResource is that how the resource
is retrieved elements. If the resource is StaticResource, it will be retrieved
only once by the element who is referencing it and it will be used for
all the resources. While the DynamicResource gets its value each time they
reference to the objects. So StaticResource is faster than the DynamicResource
, because StaticResource needs to get the value only once while the
DynamicResource needs each time.
61. What is Prism?
A. Prism is the
framework or the set of guidelines which is used to develop the WPF desktop
application as well as the Silverlight Rich Internet applications. So it’s a
kind of Design pattern to Develop the XMAL based application. It also used to
develop the Windows 7 applications. Prism mainly helps to design the loosely
coupled components which can be easily integrated with the other components of
the overall application. Prism mainly used to build the composite applications
which need various other components to be integrated.
Prism mainly
guides of creating the applications using the Model-View-ViewModel (MVVM)
model, Managed Extensibility Framework (MEF), and navigation in the
application.
To use the Prism
framework, we need to use their library called as Prism Library. So prism
Library is the inbuilt set of components which can be used in developing the
WPF and Silverlight applications.
62. Dependency Injection, Event Aggregator.
Event Aggregator
: It is the utility service which contains the events and allows the decouple
the publisher and subscriber so that they can be buildup independently.
Decouple is primarily useful when a new module needs to be added or removed or
modified. The new module can be added as per the event fired and defined in the
shell.
63. Shell,
Bootstrapper and Region Managers
A. Bootstrapper:-
An utility in WPF engine which is mainly responsible for the initialization of
the application by using the composite application library. By using the
bootstrapper we can find out how the components of the application are wired up
in the composite application library. The bootstrapper responsibility to create
the Shell or main window. Composite application library has the default
abstract class UnityBootstrapper which actually handles the initialization.
Region and Region
Managers: This is concept of Prism framework. We define the region through XAML
code and once a region is defined, automatically it will be registered with the
RegionManager. Actually the Bootstrapper registers a service called the
RegionManager at run time. RegionManager is a dictionary where the key is name
of the region. The value of the key is the reference of the IRegion interface.
RegionAdapter is used to create the instance reference of the IRegion
interface.
64. What are MEF and Unity?
A. The MEF
(Managed Extensibility Framework) is the new concept in .Net 4.0. It is used to
create the lightweight and extensible applications to create Managed
Extensibility Framework. It is not only allows the extension but also reused
within the application. Extension can be easily encapsulating the code using
the MEF.
65. How to navigate to another page?
A. There is a
class NavigationService which can be used for navigation of the WPF window:
this.NavigationService.GoForward();
//or
this.NavigationService.Navigate("MysecondPage.xaml")
Hope the answer will be helpful to all the members.
