The following example shows how to implement a custom section programmatically.
For a complete example that shows how to implement and use a custom section implemented using the attributed model, see ConfigurationElement.
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' Define a custom section.
' The CustomSection type allows to define a custom section
' programmatically.
NotInheritable Public Class CustomSection
Inherits ConfigurationSection
' The collection (property bag) that contains
' the section properties.
Private Shared _Properties As ConfigurationPropertyCollection
' Internal flag to disable
' property setting.
Private Shared _ReadOnly As Boolean
' The FileName property.
Private Shared _FileName As New ConfigurationProperty( _
"fileName", GetType(String), _
"default.txt", _
ConfigurationPropertyOptions.IsRequired)
' The MaxUsers property.
Private Shared _MaxUsers As New ConfigurationProperty( _
"maxUsers", GetType(Long), _
CType(1000, Long), _
ConfigurationPropertyOptions.None)
' The MaxIdleTime property.
Private Shared _MaxIdleTime As New ConfigurationProperty( _
"maxIdleTime", GetType(TimeSpan), _
TimeSpan.FromMinutes(5), _
ConfigurationPropertyOptions.IsRequired)
' CustomSection constructor.
Public Sub New()
' Property initialization
_Properties = _
New ConfigurationPropertyCollection()
_Properties.Add(_FileName)
_Properties.Add(_MaxUsers)
_Properties.Add(_MaxIdleTime)
End Sub 'New
' This is a key customization.
' It returns the initialized property bag.
Protected Overrides ReadOnly Property Properties() _
As ConfigurationPropertyCollection
Get
Return _Properties
End Get
End Property
Private Shadows ReadOnly Property IsReadOnly() As Boolean
Get
Return _ReadOnly
End Get
End Property
' Use this to disable property setting.
Private Sub ThrowIfReadOnly(propertyName As String)
If IsReadOnly Then
Throw New ConfigurationErrorsException( _
"The property " + propertyName + " is read only.")
End If
End Sub 'ThrowIfReadOnly
' Customizes the use of CustomSection
' by setting _ReadOnly to false.
' Remember you must use it along with ThrowIfReadOnly.
Protected Overrides Function GetRuntimeObject() As Object
' To enable property setting just assign true to
' the following flag.
_ReadOnly = True
Return MyBase.GetRuntimeObject()
End Function 'GetRuntimeObject
<StringValidator( _
InvalidCharacters:=" ~!@#$%^&*()[]{}/;'""|\", _
MinLength:=1, MaxLength:=60)> _
Public Property FileName() As String
Get
Return CStr(Me("fileName"))
End Get
Set(ByVal value As String)
' With this you disable the setting.
' Remember that the _ReadOnly flag must
' be set to true in the GetRuntimeObject.
ThrowIfReadOnly("FileName")
Me("fileName") = value
End Set
End Property
<LongValidator( _
MinValue:=1, MaxValue:=1000000, _
ExcludeRange:=False)> _
Public Property MaxUsers() As Long
Get
Return Fix(Me("maxUsers"))
End Get
Set(ByVal value As Long)
Me("maxUsers") = Value
End Set
End Property
<TimeSpanValidator( _
MinValueString:="0:0:30", _
MaxValueString:="5:00:0", ExcludeRange:=False)> _
Public Property MaxIdleTime() As TimeSpan
Get
Return CType(Me("maxIdleTime"), TimeSpan)
End Get
Set(ByVal value As TimeSpan)
Me("maxIdleTime") = Value
End Set
End Property
End Class 'CustomSection
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// Define a custom section.
// The CustomSection type allows to define a custom section
// programmatically.
public sealed class CustomSection :
ConfigurationSection
{
// The collection (property bag) that contains
// the section properties.
private static ConfigurationPropertyCollection _Properties;
// Internal flag to disable
// property setting.
private static bool _ReadOnly;
// The FileName property.
private static readonly ConfigurationProperty _FileName =
new ConfigurationProperty("fileName",
typeof(string),"default.txt",
ConfigurationPropertyOptions.IsRequired);
// The MaxUsers property.
private static readonly ConfigurationProperty _MaxUsers =
new ConfigurationProperty("maxUsers",
typeof(long), (long)1000,
ConfigurationPropertyOptions.None);
// The MaxIdleTime property.
private static readonly ConfigurationProperty _MaxIdleTime =
new ConfigurationProperty("maxIdleTime",
typeof(TimeSpan), TimeSpan.FromMinutes(5),
ConfigurationPropertyOptions.IsRequired);
// CustomSection constructor.
public CustomSection()
{
// Property initialization
_Properties =
new ConfigurationPropertyCollection();
_Properties.Add(_FileName);
_Properties.Add(_MaxUsers);
_Properties.Add(_MaxIdleTime);
}
// This is a key customization.
// It returns the initialized property bag.
protected override ConfigurationPropertyCollection Properties
{
get
{
return _Properties;
}
}
private new bool IsReadOnly
{
get
{
return _ReadOnly;
}
}
// Use this to disable property setting.
private void ThrowIfReadOnly(string propertyName)
{
if (IsReadOnly)
throw new ConfigurationErrorsException(
"The property " + propertyName + " is read only.");
}
// Customizes the use of CustomSection
// by setting _ReadOnly to false.
// Remember you must use it along with ThrowIfReadOnly.
protected override object GetRuntimeObject()
{
// To enable property setting just assign true to
// the following flag.
_ReadOnly = true;
return base.GetRuntimeObject();
}
[StringValidator(InvalidCharacters = " ~!@#$%^&*()[]{}/;'\"|\\",
MinLength = 1, MaxLength = 60)]
public string FileName
{
get
{
return (string)this["fileName"];
}
set
{
// With this you disable the setting.
// Remember that the _ReadOnly flag must
// be set to true in the GetRuntimeObject.
ThrowIfReadOnly("FileName");
this["fileName"] = value;
}
}
[LongValidator(MinValue = 1, MaxValue = 1000000,
ExcludeRange = false)]
public long MaxUsers
{
get
{
return (long)this["maxUsers"];
}
set
{
this["maxUsers"] = value;
}
}
[TimeSpanValidator(MinValueString = "0:0:30",
MaxValueString = "5:00:0",
ExcludeRange = false)]
public TimeSpan MaxIdleTime
{
get
{
return (TimeSpan)this["maxIdleTime"];
}
set
{
this["maxIdleTime"] = value;
}
}
}
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The following example is an excerpt of the configuration file as it applies to the previous example.
<?xml version="1.0" encoding="utf-8"?>
<configuration>
<configSections>
<section name="CustomSection" type="Samples.AspNet. CustomSection, CustomConfigurationSection, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" allowDefinition="Everywhere" allowExeDefinition="MachineToApplication" restartOnExternalChanges="true" />
</configSections>
<CustomSection fileName="default.txt" maxUsers="1000" maxIdleTime="00:15:00" />
</configuration>