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ConfigurationConverterBase Class

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

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 
End Class 'CustomSection 

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>

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 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

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

.NET Framework

Supported in: 3.5, 3.0, 2.0
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