Beginning ASP.NET 4.5 in CSharp and VB Opsylum

194 x CHAPTER 5 PROGRAMMING YOUR ASP.NET WEB PAGES
Read-only or write-only properties in C# are simple: Just leave out the setter (for a read-only property)
or the getter (for a write-only property). VB.NET is a bit more verbose and wants you to specify
the keyword ReadOnly or WriteOnly explicitly. The following code snippet shows a read-only
FullName property in both VB.NET and C#:
VB.NET
Public ReadOnly Property FullName() As String
Get
Return _firstName & " " & _lastName
End Get
End Property
C#
public string FullName
{
get { return _firstName + " " + _lastName; }
}
When you try to assign a value to a read-only property, you’ll get a compilation error in VS.
Similar to properties, objects can also have methods.
Methods
If properties are the things that a class has (its characteristics), then methods are the things a class
can do or the operations it can perform. A Car class, for example, has properties such as Brand,
Model, and Color. Its methods could be Drive(), Brake(), and OpenDoors(). Methods give objects
the behavior that enables them to do something.
You have already seen methods at work earlier, when this chapter discussed some ways to write
organized code using subs and functions. You simply add methods to a class by writing a function
or a sub between the start and end elements of the class. For example, imagine the Person class has
a Save method that enables the object to persist itself in the database. The method’s signature could
look like this:
VB.NET
Public Class Person
Public Sub Save()
' Implementation goes here
End Sub
End Class
C#
public class Person
{
public void Save()
{
// Implementation goes here
}
}
If you want to call the Save method to have the Person object save itself to the database, you create
an instance of it, set the relevant properties such as FirstName, and then call Save: