To create the configuration handler, we will need to create
a new class and import the System.Configuration namespace. Our new class will
also have to inherit the ConfigurationSection class. In version 1.x the
handler would implement the IConfigurationSectionHandler interface. However,
that interface has now deprecated. Continuing on, we will add an empty
construct and a "loaded" construct. I consider a class containing a
construct with all attributes a loaded construct. We will also add two
properties to the class and two attributes to each property. In Listing 1 an
example of this is shown in both Visual Basic and C#.
Listing 1 - An example of a Configuration Handler
in Visual Basic .NET and C#
[Visual Basic .NET]
'Class that creates the configuration handler
Public Class MyCustomConfigurationHandler
Inherits ConfigurationSection
'Empty Construct
Public Sub MyCustomConfigurationHandler()
End Sub
'Loaded Construct
Public Sub MyCustomConfigurationHandler(ByVal firstValue As Integer, _
secondValue As Integer)
FirstNumber = firstValue
SecondNumber = secondValue
End Sub
'First Number Property
<ConfigurationProperty("firstNumber", DefaultValue
= 1, IsRequired
= True)> _
<IntegerValidator(MinValue
= -100, MaxValue
= 100)> _
Public Property FirstNumber() As Integer
Get
Return CInt(Me("firstNumber"))
End Get
Set(ByVal Value As Integer)
Me("firstNumber") = Value
End Set
End Property
'Second Number Property
<ConfigurationProperty("secondNumber", DefaultValue
= 1, IsRequired
= True)> _
<IntegerValidator(MinValue
= -100, MaxValue
= 100)> _
Public Property SecondNumber() As Integer
Get
Return CInt(Me("secondNumber"))
End Get
Set(ByVal Value As Integer)
Me("secondNumber") = Value
End Set
End Property
End Class[Visual C# .NET]
// Class that creates the configuration handler
public class MyCustomConfigurationHandler: ConfigurationSection
{
// Empty Construct
public MyCustomConfigurationHandler(){}
// Loaded Construct
public MyCustomConfigurationHandler(Int32 firstValue, Int32 secondValue)
{
FirstNumber = firstValue;
SecondNumber = secondValue;
}
// First Number Property
[ConfigurationProperty("firstNumber", DefaultValue = 1, IsRequired = true)
][IntegerValidator(MinValue = - 100, MaxValue = 100)]
public Int32 FirstNumber
{
get
{
return (Int32)this["firstNumber"];
}
set
{
this["firstNumber"] = value;
}
}
// Second Number Property
[ConfigurationProperty("secondNumber", DefaultValue = 1, IsRequired = true)
][IntegerValidator(MinValue = - 100, MaxValue = 100)]
public Int32 SecondNumber
{
get
{
return (Int32)this["secondNumber"];
}
set
{
this["secondNumber"] = value;
}
}
}The ConfigurationProperty attribute for the property has
only one required field and that is the property name as specified in the
web.config file. The DefaultValue attribute field is just that. It is the
default value for the property. The IsRequired attribute field specifies
whether or not the property is required to be contained in the configuration
section's attribute list.
