What do you meant by Containment in C#?

Containment is the replacement of inheritence,no no if inheritance isn’t the right choice,then the answer is containment, also known as aggregation. Rather than saying that an object is an example of another object, an instance of that other object will be contained inside the object. So,instead of having a class look like a string, the class will contain a string (or array, or hash table).
The default design choice should be containment, and you should switch to inheritance only if needed(i.e., if there really is an “is-a” relationship).

Read More

How to handle generic errors in WinApp using C# ?

Pass your exception or error through catch block to this method this will catch your error and show the messagebox regarding that error.

Method which take error exception as a parameter and handle that error.
public static void LogError(Exception ex)
{
string sourceName = "Application Name";
int errorCode = "99";
string message = "The application encountered an unknown error:";
msg += "\r\nExecuting Method: " + new System.Diagnostics.StackFrame(1, false).GetMethod().Name;
message += "\r\nError Message: " + ex.Message;

EventLog.WriteEntry(sourceName , msg, EventLogEntryType.Error, errorCode );
MessageBox.Show(msg, "ERROR", MessageBoxButtons.OKCancel, MessageBoxIcon.Error);
}

Read More

What is interface and why we implement interfaces ?

Interface defined by using interface keyword .In visualstudio you can directly add class as a interface its not a class it behaves as a template of the class. Interfaces describe a group of related functionalities that can belong to any class or struct.Interfaces are provided in C# as a replacement of multiple inheritance because C# does not support multiple inheritance and it's very necessary to inherit the behaviour of one or more classes.classes can only implement the methods defined in the interface because in C#, an interface is a built-in keyword that declares a reference type that includes method declarations. if a base class implements an interface, the derived class inherits that implementation.

I am giving an example to better understand :-
Interface which contains profile name strings
public interface IProfile
{
string FirstName {get;}
string LastName {get;}
}
Implements IloggedUser interface.
public interface ILoggedUser
{
IProfile Profile
{
get;
set;
}
}
Class LoggedUser which implements ILoggedUser interface.
public class LoggedUser : ILoggedUser
{
protected IProfile _profile = null;
Constructor
public LoggedUser(IProfile Profile)
{
_profile=Profile;
}

public static LoggedUser Create(IProfile Profile)
{
LoggedUser User = new LoggedUser(Profile);
return User;
}
public IProfile Profile
{
get
{
if (_profile== null)
{
return _profile;
}
}
set
{
_profile=value;
}
}
}
Class profile which implements IProfile interface.
public class Profile : IProfile
{
string _firstName = string.Empty;
string _lastName = string.Empty;
public string FirstName
{
get
{
return _firstName;
}
}
public string LastName
{
get
{
return _lastName;
}
}
}

Read More