CLR
and C#
1.
Types of Authentication and Authorization in IIS.
A. Types of Authentication: Anonymous Authentication, Windows
Authentication, Digest Authentication
Types of Authorization:- Anonymous
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. 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 checks for the syntax and semantics of the request and then the
request goes to the ASPNet_ISAPI.dll which is the filter to filter the .aspx
files. Here the URL request split in to 2 parts- virtual directory and webpage.
Now 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 move to the HttpPipeline where the
actual execution of the page happened by using the ProcessRequest method and
creates the events of the page. After creation of event and execution of all
the event, the HTML page gets 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. 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.
Reference types: This type doesn’t 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 type in to the Reference type is
called as Boxing. Converting the Reference type data type and keep its value to
stack is called as the reference type.
byte b=
45;
Object
o = b.Tostring();
The Advantage of boxing and unboxing is that we can convert the type
of the object in to another type. The disadvantage is that it requires lot of
memory and CPU cycles to convert from one type to another type.
Object
o=10;
Int i=
Convert.ToInt32(o.ToString());
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 as:
SN -k
fileName.dll
Now it will have the unique name. 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
HttpPipeline, 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. After Processing the request 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 current web page.
11.
CLR and DLR?
A. CLR (Common Language Runtime) is the utility in the .Net framework
to run the application. It is the run-time 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 version 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 but packed as a dll. So
we can say that dll is the assembly.
There are 3 types of assemblies- Private Assembly, Shared Assembly,
and Satellite Assembly.
GAC (Global Assembly Cache)- When the assembly is required for
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. We can purchase the client certificate
from the trusted providers and then we need to install that provider for our
site. By implementing the HTTPS, all the data which is passing will be in
encrypted format and will be more secure.
16.
What are in-proc and out-proc? Where are data stored in these cases?
A. In-Proc and Out-Proc is the types of Sessions where the session
data can be stored in the process memory of the server and in the separate
state server.
When the session data is stored in the process memory of the server,
the session is called as the In-Proc server. In this case when the server is
restarted, the session data will be lost.
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 Out-Proc 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 in-Proc session state, the session data is stored in
the Process memory of the Server where the application is running.
In the Out-proc 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 base 64 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 engines? How is it diff from ASP Engines?
A. RAZOR engine is the new concept in the MVC 3 which is mainly used
to create the views in the MVC applications. It created the cshtml pages for
the MVC application and cshtml pages can be generated automatically by using
the Razor engine.ASP engine create the aspx pages while Razor engine creates
the pages.
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 Synchronous JavaScript and XML which is used for the
Asynchronous calls from the server. It uses internally the JavaScript 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 can JavaScript 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 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 user control, we can use the same control in the
various pages. User controls can be created by combining more than one control.
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 need in each page where we want
to use the user control. User controls can't be included in to the toolbox.
Server controls are those controls which can be found in the toolbox
and can be directly drag to the application like textbox, button etc. For the
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 in 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 caste when required.
Like object mybject = "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;
Dynamic- It’s a keyword introduces with the .net 4.0 and used to keep
the data similar to the var keyword. 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 are same. in general, we use method in
.net but in scripting language we use function like JavaScript function.
Here the difference can be Function always returns a value which
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. Collection of the Abstract (Incomplete) and Concrete (complete)
methods is called as the Abstract class. If there is at least one abstract method
in a class, the class must be abstract class.
When there is the similar behavior, we can use the abstract class.
e.g. We want to calculate the area of few component. As this is not
generic to the application. We have only few component- 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 member
}
Now in the child class, let’s say i have a circle class and want to
calculate the area of the circle:
public
class Cicle: MyAbstractClass
{
public
override void Area()
{
// calculate the area of the circle
}
}
In the similar fashion, we can calcite the area of other shapes.
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 overrides in the child class.
e.g. Print functionality of the application can have an interface
like:
interface
Inf
{
void
Print();
}
Now as this is the generic functionality and can be implemented in any
of the page so we have taken it as interface. Now we can implement this
functionality in to any page like:
class
MyClass:Inf
{
public
void print
{
// write details about the print
}
// 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)
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 is same but they are implemented in the different class.
We use virtual keyword in the base class method to be overrides in the child
class using the override keyword.
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;
}
}
When the run-time (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 there prototypes (parameters)
are different and it is implemented in the same class.
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 in the
child class. So we don’t matter whatever is written in the base class. We only
need to force the child class to implement my required functionality.
Abstract keyword is used to get the abstraction behavior.
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 text changed
event.
We can get more details about the delegate and events from the below
link:
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:
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 work 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 express,
you can go through the below link:
32.
Multithreading. How to implement Multithreading?
A. Executing more than one process simultaneously 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 some data using View.
View doesn’t 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
which is created as a result of any sql statement to hold the intermediate
values.
Views are used to format the rows individually. By using the views, 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 join 2 or more tables using some conditions.
There are 3 types of Joins in SQL Server database-
a. Left Outer Join
b. Right Outer Join
c. Full Join
In order to extract the matched row from both the tables and unmatched
row from the first table, left Outer join is used. The syntax for left outer
join condition is:
T.Col1* = T2.Col1
In order to extract the matched row from both the tables and unmatched
row from the second table, right Outer join is used. The syntax for right outer
join condition is:
T.Col1 = *T2.Col1
In order to extract the matched row from both the tables and unmatched
row from the first table and then unmatched row from the second table, full
join is used. The syntax for full join condition is:
T.Col1* = *T2.Col1
37.
Exception handling.
A. Exception Handling is the way to handle the unexpected error. 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 @@Error which is the global variable and used to get the error.
RaiseError is another inbuilt method which is used to display the error.
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 so that we can
achieve high response time to the front end. 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 is 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 second instance of the same table. So we 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 id is also an employee id. 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. Indexes are one 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 doesn’t allow null value while the
unique key allow. The limitation of the null in unique key is that it allows
only one Null so in only 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 Date type. 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
You can go through the below link for couple of work around:
WCF
46.
What is WCF also known as?
A. WCF (Windows Communication Foundation) is also know an
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
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). 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 creeat 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 ca 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 stack panel either horizontally or vertically. So
it provides two types of orientations- Horizontal Orientation and Vertical
orientation.
You can go through the below link for more detailed explanation and
the code snippet:
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
in to 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.
You can go through the below link for more details:
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 in to 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:
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.
Please go through the below link for more details:
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 whoe 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 to get it.
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.
You can go through the below link for more details and the use of the
components of the Prism framework:
62.
Dependency Injection, Event Aggregator.
A. For the details about the dependency injection, you can follow the
below link:
EventAggregator : 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.
For more details about the Event Aggregator, you can follow the below
link:
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.
You can go through the below link for more details about the
bootstrapper:
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.
You can go through the below link for more details about the Region
and Region Manager:
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.
For more details, you can go through the below link:
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")
1. What is the difference
between IEnumerable and IQueryable?
Ans. IEnumerable and
IQuerable are used to query data from database and collections. The
IEnumerable is basically inherited from IQueryable, so it’s having all the
features of the IQueryable in addition to its having additional own features.
|
S.No
|
IEnumerable
|
IQueryable
|
|
1.
|
Exists in
System.Collections Namespace
|
Exists in System.Linq
Namespace
|
|
2.
|
Can move to forward
only in the collection.
|
Can move to forward,
backward or in between the items.
|
|
3.
|
Best for collection
like List, Array or in-memory collection
|
Best for the
collections which is out memory like services, remote databases etc
|
|
4.
|
Suitable for LINQ to
Objet and Linq to XML queries.
|
Suitable for Linq to
SQL queries
|
|
5.
|
It doesn’t supports
custom query, Lazy loading so it’s not good for paging scenarios.
|
It supports custom
query using CreateQuery and Execute methods. Also support lazy loading so
good for the paging scenarios.
|
|
6.
|
The extension methods
which supports be IEnumrable takes the functional objects as the parameters.
|
The extension methods
which supports be IEnumrable takes the expression tree expressions as the
parameters.
|
In the first example (By
using the IEnumerable), the generated SQL is as below:
In the second example (By
using the IQueryable), the generated SQL is as below:
We can see that by using
the IQueryable, the performance will increase as it has the TOP clause in the
query.
2. What is cross
site scripting? (XSS)
Ans. Cross-site scripting is
the way to attacks and insert the vulnerabilities in Web page. This attack is
injected by client-side code. The script which is inject by the client can
embed itself in response data. The response data which send back to the
malicious user. The browser can’t recognize the scripts as it is responded from
the trusted source.
The cross-site scripting
attacks also work on the HTTP and HTTPS.
There are 2 ways to
prevent the cross site scripting attack:
Constrain input- Validate
the input length, type, formatting, range etc
Encode output- Send the
input data with encode e.g. Encode to HTML
To prevent the cross-site
attack, we can set the below attributes in web.config file:
3. If I want to see my
website similar in all the browsers then what I need to do for that?
Ans. If you want to see the
website with the same look and feel then you need to write the common css style
which should be same for all browsers. Actually every browser will not support
every css elements so it is not possible to use the same css to support all the
browsers. You need to write the common css elements in the file and then apply
it across the website. Else you need to write the separate css file as per the
browser.
4. If say 1 Lac users are
using any particular website then what you will do to prevent crashing of
server? Which care you will take at the time of coding?
Ans. There are the ways
like we can have multiple servers to handle the requests from the users. In
this, we can have the Web Gardening concept where we can have the multiple web
servers and then one main server to handle the number of requests and switch
the requests to other servers.
5. Why to use
design patterns?
Ans. Design Pattern is the way
to solve the recurring problems which occur during the designing of the
applications. As the requirements increases, the projects becomes complex and
due to the complexity, it’s difficult to maintain it.
With the help of design
patterns, we can reduce the complexity and with the help of OOPs paradigm, we
can make our applications more efficient in all the ways.
According to the GoF
(Gang of Four) company, the Design Patterns can be classified to 3 ways:-
·
Creational
Design Pattern
·
Behavioral
Design Pattern
·
Structural
Design pattern
6. If I have a class C and
two interfaces I1 and I2 and I have add method inside I1 and I2 then how to
specify which one has to be called?
Ans. By using the
explicit implement interface, we can implement the same method which is defined
in both the interfaces.
e.g.
The implementation will
be as below:
7. Garbage collection uses
which type of algorithm? How it will find which object is unused?
Ans. Mark-And-Release is the
algorithm which the garbage collection uses to reclaim the memory of the
unreferenced objects which are no longer used.
The algorithm
Mark-and-Release work in 2 steps:-
a. In
the first steps, it marks all the accessible objects of the heap memory. This
is called as mark phase.
b. In
the second step, scan the heap and reclaim all the unmarked objects by the
Garbage Collection algorithm. This step is called as sweep phase.
Below are the algorithm
steps:
For the detailed
description, follow the below link:
8. What is the difference
between out and ref?
Ans: Ref and Out are the
parameters which are used in the methods [ref] and [out] both allows the
called method to modify a parameter. The difference between them is what
happens before you make a call.
·
[ref]
means that the parameter has a value on it before going into the
function. The called function can read and or change the value any time. The
parameter goes in, then comes out
·
[out]
means that the parameter has no official value before going into the function.
The called function must initialize it. The parameter only goes out.
So the main difference
between the ref and out parameter is that the out parameter doesn't needs to
be initialized while the ref parameter must
be initialized before passing to the function.
9. Is it
possible to use more than one out parameter?
Ans. As we know that
the method always returns a single value but by using the out parameter, we can
return multiple values from the method or function.
In C# we can write the
small code snippet which will describe to return the multiple values using the
out parameters:
We can also use the
struct which will contain the multiple values as the return:
There is another way to
return multiple values like using Tuple class (newly introduces in .Net 4.0).
The tuple class can return the object which can contain multiple values in
it.
10. Is it possible to use
.js files used under script will be in body and not in header? Why?
Ans. The .js file is used in
header because first the .js file should be loaded to the application and then
rest of the content should be load.
Hope the answer will be helpful to
all the members.
This is very helpful and informative.
ReplyDeleteThanks for sharing...
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