ConfigurationConverterBase Class

Note: This class is new in the .NET Framework version 2.0.

The base class for the configuration converter types.

Namespace: System.Configuration
Assembly: System.Configuration (in system.configuration.dll)

'Declaration
Public MustInherit Class ConfigurationConverterBase
	Inherits TypeConverter
'Usage
Dim instance As ConfigurationConverterBase

public abstract class ConfigurationConverterBase extends TypeConverter
public abstract class ConfigurationConverterBase extends TypeConverter

The ConfigurationConverterBase is the base class for the converter configuration types. These are types that convert strings, found in the configuration file, to and from the related strongly typed properties.

The following code examples show how to derive from the ConfigurationConverterBase class to create a custom TimeSpan converter type. Also, the examples show how to use this type in a custom section.

The following code example shows how to create a custom TimeSpan converter type from the ConfigurationConverterBase class.

Imports System
Imports System.Collections.Generic
Imports System.Text
Imports System.Configuration
Imports System.Globalization
Imports System.ComponentModel




NotInheritable Public Class CustomTimeSpanMinutesConverter
    Inherits ConfigurationConverterBase
    
    Friend Function ValidateType(ByVal value As Object, _
    ByVal expected As Type) As Boolean
        Dim result As Boolean

        If Not (value Is Nothing) _
        AndAlso value.ToString() <> expected.ToString() Then
            result = False
        Else
            result = True
        End If
        Return result

    End Function 'ValidateType
    
    
    Public Overrides Function CanConvertTo( _
    ByVal ctx As ITypeDescriptorContext, _
    ByVal type As Type) As Boolean
        Return (type.ToString() = GetType(String).ToString())

    End Function 'CanConvertTo
    
    Public Overrides Function CanConvertFrom( _
    ByVal ctx As ITypeDescriptorContext, _
    ByVal type As Type) As Boolean
        Return (type.ToString() = GetType(String).ToString())

    End Function 'CanConvertFrom
    
    Public Overrides Function ConvertTo( _
    ByVal ctx As ITypeDescriptorContext, _
    ByVal ci As CultureInfo, ByVal value As Object, _
    ByVal type As Type) As Object
        ValidateType(value, GetType(TimeSpan))

        Dim data As Long = _
        Fix(CType(value, TimeSpan).TotalMinutes)

        Return data.ToString(CultureInfo.InvariantCulture)

    End Function 'ConvertTo
    
    Public Overrides Function ConvertFrom( _
    ByVal ctx As ITypeDescriptorContext, _
    ByVal ci As CultureInfo, ByVal data As Object) As Object

        Dim min As Long = _
        Long.Parse(CStr(data), CultureInfo.InvariantCulture)

        Return TimeSpan.FromMinutes(System.Convert.ToDouble(min))

    End Function 'ConvertFrom

End Class 'CustomTimeSpanMinutesConverter 

The following code example shows how to define a custom section that uses the previous custom TimeSpan converter.

' Define a custom section.
NotInheritable Public Class CustomSection
    Inherits ConfigurationSection
    
    
    Public Sub New() 
    
    End Sub 'New
    
    
    
    <ConfigurationProperty("fileName", _
    DefaultValue:="   default.txt  "), _
    TypeConverter(GetType(WhiteSpaceTrimStringConverter))> _
    Public Property FileName() As String
        Get
            Return CStr(Me("fileName"))
        End Get
        Set(ByVal value As String)
            Me("fileName") = value
        End Set
    End Property

    
    <ConfigurationProperty("maxIdleTime"), _
    TypeConverter(GetType(CustomizedTimeSpanMinutesConverter))> _
    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
    
    <ConfigurationProperty("timeDelay", _
    DefaultValue:="infinite"), _
    TypeConverter(GetType(InfiniteTimeSpanConverter))> _
    Public Property TimeDelay() As TimeSpan
        Get
            Return CType(Me("timeDelay"), TimeSpan)
        End Get
        Set(ByVal value As TimeSpan)
            Me("timeDelay") = Value
        End Set
    End Property
    
    <ConfigurationProperty("cdStr", _
    DefaultValue:="str0, str1", _
    IsRequired:=True), _
    TypeConverter(GetType(CommaDelimitedStringCollectionConverter))> _
    Public Property CdStr() As StringCollection
        Get
            Return CType(Me("cdStr"), StringCollection)
        End Get

        Set(ByVal value As StringCollection)
            Me("cdStr") = value
        End Set
    End Property
    
    
    Public Enum Permissions
        FullControl = 0
        Modify = 1
        ReadExecute = 2
        Read = 3
        Write = 4
        SpecialPermissions = 5
    End Enum 'Permissions
    
    
    <ConfigurationProperty("permission", _
    DefaultValue:=Permissions.Read)> _
    Public Property Permission() As Permissions
        Get
            Return CType(Me("permission"), Permissions)
        End Get

        Set(ByVal value As Permissions)
            Me("permission") = Value
        End Set
    End Property
    
    
    <ConfigurationProperty("maxUsers", _
    DefaultValue:="infinite"), _
    TypeConverter(GetType(InfiniteIntConverter))> _
    Public Property MaxUsers() As Integer
        Get
            Return Fix(Me("maxUsers"))
        End Get
        Set(ByVal value As Integer)
            Me("maxUsers") = Value
        End Set
    End Property


The following code example shows how to create and modify a configuration file using the previous custom section.

Imports System
Imports System.Collections.Generic
Imports System.Text
Imports System.Configuration
Imports System.Globalization
Imports System.ComponentModel



' Define a custom section.

NotInheritable Public Class CustomSection
   Inherits ConfigurationSection
   
   
   Public Sub New()
   End Sub 'New
   
   
    <ConfigurationProperty("fileName", _
    DefaultValue:="default.txt", _
    IsRequired:=True, IsKey:=False), _
    StringValidator(InvalidCharacters:=" ~!@#$%^&*()[]{/;'""|\", _
    MinLength:=1, MaxLength:=60)> _
    Public Property FileName() As String
        Get
            Return CStr(Me("fileName"))
        End Get
        Set(ByVal value As String)
            Me("fileName") = value
        End Set
    End Property
   
   
   
    <ConfigurationProperty("maxIdleTime"), _
    TypeConverter(GetType(TsMinutesConverter))> _
    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 


NotInheritable Public Class TsMinutesConverter
   Inherits ConfigurationConverterBase
   
   Friend Function ValidateType(value As Object, expected As Type) As Boolean
      Dim result As Boolean
      
        If Not (value Is Nothing) _
        AndAlso (value.GetType().Equals(expected) <> True) Then
            result = False
        Else
            result = True
        End If
      Return result
   End Function 'ValidateType
   
   
    Public Overrides Function CanConvertTo( _
    ByVal ctx As ITypeDescriptorContext, _
    ByVal type As Type) As Boolean

        Return type.Equals(GetType(String))

    End Function 'CanConvertTo
   

    Public Overrides Function CanConvertFrom( _
    ByVal ctx As ITypeDescriptorContext, _
    ByVal type As Type) As Boolean

        Return type.Equals(GetType(String))

    End Function 'CanConvertFrom
   

    Public Overrides Function ConvertTo( _
    ByVal ctx As ITypeDescriptorContext, ByVal ci As CultureInfo, _
    ByVal value As Object, ByVal type As Type) As Object
        ValidateType(value, GetType(TimeSpan))

        Dim data As Long = _
        Fix(CType(value, TimeSpan).TotalMinutes)

        Return data.ToString(CultureInfo.InvariantCulture)

    End Function 'ConvertTo
   
   
    Public Overrides Function ConvertFrom( _
    ByVal ctx As ITypeDescriptorContext, ByVal ci As CultureInfo, _
    ByVal data As Object) As Object

        Dim min As Long = _
        Long.Parse(CStr(data), _
        CultureInfo.InvariantCulture)

        Return TimeSpan.FromMinutes( _
        System.Convert.ToDouble(min))

    End Function 'ConvertFrom
End Class 'TsMinutesConverter

Class UsingConfigutationConverterBase
   
   
   ' Create a custom section.
   Shared Sub CreateSection()
      Try
         
         Dim customSection As CustomSection
         
         ' Get the current configuration file.
            Dim config _
            As System.Configuration.Configuration = _
            ConfigurationManager.OpenExeConfiguration( _
            ConfigurationUserLevel.None)
         
         ' Create the section entry  
         ' in the <configSections> and the 
         ' related target section in <configuration>.
         If config.Sections("CustomSection") Is Nothing Then
            customSection = New CustomSection()
            config.Sections.Add("CustomSection", customSection)
            customSection.SectionInformation.ForceSave = True
            config.Save(ConfigurationSaveMode.Full)
         End If
      Catch err As ConfigurationErrorsException
         Console.WriteLine(err.ToString())
      End Try
   End Sub 'CreateSection
    
   
   
   ' Change custom section and write it to disk.
   Shared Sub SerializeCustomSection()
      Try
            Dim config _
               As System.Configuration.Configuration = _
               ConfigurationManager.OpenExeConfiguration( _
               ConfigurationUserLevel.None)

            Dim customSection _
            As CustomSection = _
            config.Sections.Get("CustomSection")
         Dim ts As New TimeSpan(1, 30, 30)
         
         customSection.MaxIdleTime = ts
         
         config.Save()
         
            Dim maxIdleTime As String = _
            customSection.MaxIdleTime.ToString()
         
            Console.WriteLine( _
            "New max idle time: {0", maxIdleTime)
      Catch e As Exception
         Console.WriteLine(e.ToString())
      End Try
   End Sub 'SerializeCustomSection
    
   
   ' Read custom section from disk.
   Shared Sub DeserializeCustomSection()
      
      Try
            Dim config _
            As System.Configuration.Configuration = _
            ConfigurationManager.OpenExeConfiguration( _
            ConfigurationUserLevel.None)
         
            Dim customSection _
            As CustomSection = _
            config.Sections.Get("CustomSection")
         
            Dim maxIdleTime As TimeSpan = _
            customSection.MaxIdleTime
         
         
            Console.WriteLine( _
            "Max idle time: {0", maxIdleTime.ToString())
      Catch e As Exception
         Console.WriteLine(e.ToString())
      End Try
   End Sub 'DeserializeCustomSection
   

    Public Overloads Shared Sub Main(ByVal args() As String)
        CreateSection()
        SerializeCustomSection()
        DeserializeCustomSection()
    End Sub 'Main 
End Class 'UsingConfigutationConverterBase

The following is a configuration excerpt as used by the previous example.

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <configSections>
    <section name="CustomSection" 
      type="Samples.AspNet.CustomSection, 
      ConfigurationConverters, 
      Version=1.0.0.0, Culture=neutral, 
      PublicKeyToken=null" 
      allowDefinition="Everywhere" 
      allowExeDefinition="MachineToApplication" 
      restartOnExternalChanges="true" />
  </configSections>
  <CustomSection fileName="default.txt" maxIdleTime="90" />
</configuration>

System.Object
   System.ComponentModel.TypeConverter
    System.Configuration.ConfigurationConverterBase
       Derived Classes

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0

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