ConfigurationSection Class

Definition

Represents a section within a configuration file.

public ref class ConfigurationSection abstract : System::Configuration::ConfigurationElement
public abstract class ConfigurationSection : System.Configuration.ConfigurationElement
type ConfigurationSection = class
    inherit ConfigurationElement
Public MustInherit Class ConfigurationSection
Inherits ConfigurationElement
Inheritance
ConfigurationSection
Derived

Examples

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.

// 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;
        }
    }
}
' 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
   
   
   ' 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
   
   
   
   ' 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

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>

Remarks

You use the ConfigurationSection class to implement a custom section type. Extend the ConfigurationSection class to provide custom handling and programmatic access to custom configuration sections. For information about how use custom configuration sections, see How to: Create Custom Configuration Sections Using ConfigurationSection.

A section registers its handling type with an entry in the configSections element. For an example, see the configuration file excerpt shown in the Example section.

Note

In previous versions of the .NET Framework, configuration section handlers were used to make changes to configuration settings programmatically. Now, all the default configuration sections are represented by classes that extend the ConfigurationSection class.

Notes to Implementers

You can use a programmatic or a declarative (attributed) coding model to create custom configuration sections:

  • Programmatic model. This model requires that for each section attribute you create a property to get or set its value and add it to the internal property bag of the underlying ConfigurationElement base class.

  • Declarative model. This simpler model, also called the attributed model, allows you to define a section attribute by using a property and decorating it with attributes. These attributes instruct the ASP.NET configuration system about the property types and their default values. With this information, obtained through reflection, the ASP.NET configuration system creates the section property objects and performs the required initialization.

The Configuration class allows programmatic access for editing configuration files. You can access these files for reading or writing as follows:

  • Reading. You use GetSection(String) or GetSectionGroup(String) to read configuration information. Note that the user or process that reads must have the following permissions:

    • Read permission on the configuration file at the current configuration hierarchy level.

    • Read permissions on all the parent configuration files.

    If your application needs read-only access to its own configuration, it is recommended you use the GetSection overloaded methods in the case of Web applications, or the GetSection(String) method in the case of client applications.

    These methods provide access to the cached configuration values for the current application, which has better performance than the Configuration class.

Note: If you use a static GetSection method that takes a path parameter, the path parameter must refer to the application in which the code is running; otherwise, the parameter is ignored and configuration information for the currently-running application is returned.

  • Writing. You use one of the Save methods to write configuration information. Note that the user or process that writes must have the following permissions:

    • Write permission on the configuration file and directory at the current configuration hierarchy level.

    • Read permissions on all the configuration files.

Constructors

ConfigurationSection()

Initializes a new instance of the ConfigurationSection class.

Properties

CurrentConfiguration

Gets a reference to the top-level Configuration instance that represents the configuration hierarchy that the current ConfigurationElement instance belongs to.

(Inherited from ConfigurationElement)
ElementInformation

Gets an ElementInformation object that contains the non-customizable information and functionality of the ConfigurationElement object.

(Inherited from ConfigurationElement)
ElementProperty

Gets the ConfigurationElementProperty object that represents the ConfigurationElement object itself.

(Inherited from ConfigurationElement)
EvaluationContext

Gets the ContextInformation object for the ConfigurationElement object.

(Inherited from ConfigurationElement)
HasContext

Gets a value that indicates whether the CurrentConfiguration property is null.

(Inherited from ConfigurationElement)
Item[ConfigurationProperty]

Gets or sets a property or attribute of this configuration element.

(Inherited from ConfigurationElement)
Item[String]

Gets or sets a property, attribute, or child element of this configuration element.

(Inherited from ConfigurationElement)
LockAllAttributesExcept

Gets the collection of locked attributes.

(Inherited from ConfigurationElement)
LockAllElementsExcept

Gets the collection of locked elements.

(Inherited from ConfigurationElement)
LockAttributes

Gets the collection of locked attributes.

(Inherited from ConfigurationElement)
LockElements

Gets the collection of locked elements.

(Inherited from ConfigurationElement)
LockItem

Gets or sets a value indicating whether the element is locked.

(Inherited from ConfigurationElement)
Properties

Gets the collection of properties.

(Inherited from ConfigurationElement)
SectionInformation

Gets a SectionInformation object that contains the non-customizable information and functionality of the ConfigurationSection object.

Methods

DeserializeElement(XmlReader, Boolean)

Reads XML from the configuration file.

(Inherited from ConfigurationElement)
DeserializeSection(XmlReader)

Reads XML from the configuration file.

Equals(Object)

Compares the current ConfigurationElement instance to the specified object.

(Inherited from ConfigurationElement)
GetHashCode()

Gets a unique value representing the current ConfigurationElement instance.

(Inherited from ConfigurationElement)
GetRuntimeObject()

Returns a custom object when overridden in a derived class.

GetTransformedAssemblyString(String)

Returns the transformed version of the specified assembly name.

(Inherited from ConfigurationElement)
GetTransformedTypeString(String)

Returns the transformed version of the specified type name.

(Inherited from ConfigurationElement)
GetType()

Gets the Type of the current instance.

(Inherited from Object)
Init()

Sets the ConfigurationElement object to its initial state.

(Inherited from ConfigurationElement)
InitializeDefault()

Used to initialize a default set of values for the ConfigurationElement object.

(Inherited from ConfigurationElement)
IsModified()

Indicates whether this configuration element has been modified since it was last saved or loaded when implemented in a derived class.

IsReadOnly()

Gets a value indicating whether the ConfigurationElement object is read-only.

(Inherited from ConfigurationElement)
ListErrors(IList)

Adds the invalid-property errors in this ConfigurationElement object, and in all subelements, to the passed list.

(Inherited from ConfigurationElement)
MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
OnDeserializeUnrecognizedAttribute(String, String)

Gets a value indicating whether an unknown attribute is encountered during deserialization.

(Inherited from ConfigurationElement)
OnDeserializeUnrecognizedElement(String, XmlReader)

Gets a value indicating whether an unknown element is encountered during deserialization.

(Inherited from ConfigurationElement)
OnRequiredPropertyNotFound(String)

Throws an exception when a required property is not found.

(Inherited from ConfigurationElement)
PostDeserialize()

Called after deserialization.

(Inherited from ConfigurationElement)
PreSerialize(XmlWriter)

Called before serialization.

(Inherited from ConfigurationElement)
Reset(ConfigurationElement)

Resets the internal state of the ConfigurationElement object, including the locks and the properties collections.

(Inherited from ConfigurationElement)
ResetModified()

Resets the value of the IsModified() method to false when implemented in a derived class.

SerializeElement(XmlWriter, Boolean)

Writes the contents of this configuration element to the configuration file when implemented in a derived class.

(Inherited from ConfigurationElement)
SerializeSection(ConfigurationElement, String, ConfigurationSaveMode)

Creates an XML string containing an unmerged view of the ConfigurationSection object as a single section to write to a file.

SerializeToXmlElement(XmlWriter, String)

Writes the outer tags of this configuration element to the configuration file when implemented in a derived class.

(Inherited from ConfigurationElement)
SetPropertyValue(ConfigurationProperty, Object, Boolean)

Sets a property to the specified value.

(Inherited from ConfigurationElement)
SetReadOnly()

Sets the IsReadOnly() property for the ConfigurationElement object and all subelements.

(Inherited from ConfigurationElement)
ShouldSerializeElementInTargetVersion(ConfigurationElement, String, FrameworkName)

Indicates whether the specified element should be serialized when the configuration object hierarchy is serialized for the specified target version of the .NET Framework.

ShouldSerializePropertyInTargetVersion(ConfigurationProperty, String, FrameworkName, ConfigurationElement)

Indicates whether the specified property should be serialized when the configuration object hierarchy is serialized for the specified target version of the .NET Framework.

ShouldSerializeSectionInTargetVersion(FrameworkName)

Indicates whether the current ConfigurationSection instance should be serialized when the configuration object hierarchy is serialized for the specified target version of the .NET Framework.

ToString()

Returns a string that represents the current object.

(Inherited from Object)
Unmerge(ConfigurationElement, ConfigurationElement, ConfigurationSaveMode)

Modifies the ConfigurationElement object to remove all values that should not be saved.

(Inherited from ConfigurationElement)

Applies to

See also