Interface
Interface are implemented by class or structure , it is a contract , how a class or structure will behave .Any object implement interface will make sure of implement property defined in the interface . An interface property have to define in the same data type , parameter and same property .For example an interface A has property calculateAge with return type integer .Now I am implementing interface A on class B , I have to declare calculateAge with return type integer . either compiler will through error “does not implement interface member Interfaceimplement.A.calcualtedag int”
A simple interface with no method
A Simple class with Interface
}
Now I am writing a interface with method
Now a class with Interface implementation
Some points to remember
Generally developer write class method different name with same implementation . For example a developer has declared a method name "Save" to class A , later he is writing "SaveData" in class B.But both purpose is same .Interface allow to overcome this problem.
Interface are implemented by class or structure , it is a contract , how a class or structure will behave .Any object implement interface will make sure of implement property defined in the interface . An interface property have to define in the same data type , parameter and same property .For example an interface A has property calculateAge with return type integer .Now I am implementing interface A on class B , I have to declare calculateAge with return type integer . either compiler will through error “does not implement interface member Interfaceimplement.A.calcualtedag int”
A simple interface with no method
public interface
MyInterface
{
}
A Simple class with Interface
public class
MyClass : MyInterface
{
Now I am writing a interface with method
public interface
MyInterface
{
void MySuv(int x)
{
}
}Now a class with Interface implementation
public class
Myclass : MyInterface
{
public void
MySub (int x)
{
//do you own logic
}
}Some points to remember
- Interface is a point where two point , organization subject together
- Interface can not have a definition , that is we can not write body of Interface member
- We ca not declare variable in interface
- Interface can not have fields
- All interface method have to define in implemented class
- We can not define access modifier on interface method
- We can implement interface to Abstract class
- We can apply access modifier on interface
Generally developer write class method different name with same implementation . For example a developer has declared a method name "Save" to class A , later he is writing "SaveData" in class B.But both purpose is same .Interface allow to overcome this problem.
Implementation Interface –Now we are discussing how method
of Interface is implemented in class or structure , the first step define
method with same name and signature in the class and do implementation.
public interface
MyInterface
{
void calculateAge(DateTime Date_of_Birth)
{
}
}
public class
student : MyInterface
{
public void
calculateAge(DateTime Date_of_Birth)
{
int t_year=;//calculation logig here
}
}
Multiple Interface Implementation : In.Net , it is not
possible to implement multiple inheritance ,but it is possible to implement
multiple Interface .
public interface
MyInterface1
{
void calculateAge(DateTime Date_of_Birth)
{
}
}
public interface
MyInterface2
{
void calculateMarks()
{
}
}
public class
student : MyInterface1,
MyInterface2
{
public void
calculateAge(DateTime Date_of_Birth)
{
int t_year=;//calculation logig here
}
public void calculateMarks()
{
int t_year=;//calculation logig here
}
}
You need to declared all construct of the both interface
.What happen when Multiple Interfece has same named method , for example Interface1 and Interface2 has same name
method A , what will happen when both has same parameter & same
signature.C# provide us the way to tell compiler , with method to use.During
calling , tell compiler the Interface name , then method name , for Example
public interface
A
{
void method1(DateTime Date_of_Birth)
{
}
}
public interface
B
{
void method1(DateTime Date_of_Birth)
{
}
}
public class
student : A,B
{
public void
A.method1(DateTime
Date_of_Birth)
{
int t_year=;//calculation logig here
}
public void B.method1(DateTime Date_of_Birth)
{
int t_year=;//calculation logig here
}
}
Now the common question is what is the difference between Abstract
Class and Interface .Why we should use Abstract Class and why we should Interface
? here is the points .A class can inherits only single Abstract Class but a class
can inherits multiple Interface In Abstract can contain contact , method , sub , but Interface
can contain method ,sub.In Abstract Class , we can access modifier public , private
, protected but Interface can not have such option.
