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ConfigurationConverterBase Class

The base class for the configuration converter types.

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

public abstract class ConfigurationConverterBase : 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.

using System;
using System.Collections.Generic;
using System.Text;
using System.Configuration;
using System.Globalization;
using System.ComponentModel;


public sealed class CustomTimeSpanMinutesConverter :
    ConfigurationConverterBase
{
    internal bool ValidateType(object value, 
        Type expected)
    {
        bool result;

        if ((value != null) &&
            (value.GetType() != expected))
            result = false;
        else
            result = true;

        return result;
    }

    public override bool CanConvertTo(
        ITypeDescriptorContext ctx, Type type)
    {
        return (type == typeof(string));
    }

    public override bool CanConvertFrom(
        ITypeDescriptorContext ctx, Type type)
    {
        return (type == typeof(string));
    }

    public override object ConvertTo(
        ITypeDescriptorContext ctx, CultureInfo ci,
        object value, Type type)
    {
        ValidateType(value, typeof(TimeSpan));

        long data = (long)(((TimeSpan)value).TotalMinutes);

        return data.ToString(CultureInfo.InvariantCulture);
    }

    public override object ConvertFrom(
        ITypeDescriptorContext ctx, CultureInfo ci, object data)
    {

        long min = long.Parse((string)data,
            CultureInfo.InvariantCulture);

        return TimeSpan.FromMinutes((double)min);
    }

}

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

    // Define a custom section. 
    public sealed class CustomSection :
        ConfigurationSection
    {

        public CustomSection() 
        {

        }

        [ConfigurationProperty("fileName", DefaultValue="   default.txt  ")]
        [TypeConverter(typeof(WhiteSpaceTrimStringConverter))]
        public String FileName
        {
            get
            {
                return (String)this["fileName"];
            }
            set
            {
                this["fileName"] = value;
            }
        }

        [ConfigurationProperty("maxIdleTime")]
        [TypeConverter(typeof(CustomizedTimeSpanMinutesConverter))]
        public TimeSpan MaxIdleTime
        {
            get
            {
                return (TimeSpan)this["maxIdleTime"];
            }
            set
            {
                this["maxIdleTime"] = value;
            }
        }

        [ConfigurationProperty("timeDelay", 
            DefaultValue = "infinite")]
        [TypeConverter(typeof(InfiniteTimeSpanConverter))]
        public TimeSpan TimeDelay
        {
            get
            {
                return (TimeSpan)this["timeDelay"];
            }
            set
            {
                this["timeDelay"] = value;
            }
        }

        [ConfigurationProperty("cdStr", 
            DefaultValue = "str0, str1",
           IsRequired = true)]

        [TypeConverter(typeof(
            CommaDelimitedStringCollectionConverter))]
        public StringCollection CdStr
        {
            get
            {
                return (StringCollection)this["cdStr"];
            }

            set
            {
                this["cdStr"] = value;
            }

        }



        public enum Permissions
        {
            FullControl         = 0,
            Modify              = 1,
            ReadExecute         = 2,
            Read                = 3,
            Write               = 4,
            SpecialPermissions  = 5
        }

        [ConfigurationProperty("permission", DefaultValue = Permissions.Read)]
        public Permissions Permission
        {
            get
            {
                return (Permissions)this["permission"];
            }

            set
            {
                this["permission"] = value;
            }

        }


        [ConfigurationProperty("maxUsers", DefaultValue="infinite")]
        [TypeConverter(typeof(InfiniteIntConverter))]
        public int MaxUsers
        {
            get
            {
                return (int)this["maxUsers"];
            }
            set
            {
                this["maxUsers"] = value;
            }
        }

    }

}

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

using System;
using System.Collections.Generic;
using System.Text;
using System.Configuration;
using System.Globalization;
using System.ComponentModel;

namespace Samples.AspNet
{

    // Define a custom section. 
    public sealed class CustomSection :
        ConfigurationSection
    {

        public CustomSection()
        { }

        [ConfigurationProperty("fileName", DefaultValue = "default.txt",
            IsRequired = true, IsKey = false)]
        [StringValidator(InvalidCharacters = " ~!@#$%^&*()[]{}/;'\"|\\",
            MinLength = 1, MaxLength = 60)]
        public string FileName
        {
            get
            {
                return (string)this["fileName"];
            }
            set
            {
                this["fileName"] = value;
            }
        }


        [ConfigurationProperty("maxIdleTime")]
        [TypeConverter(typeof(TsMinutesConverter))]
        public TimeSpan MaxIdleTime
        {
            get
            {
                return (TimeSpan)this["maxIdleTime"];
            }
            set
            {
                this["maxIdleTime"] = value;
            }
        }

    }

    public sealed class TsMinutesConverter :
        ConfigurationConverterBase
    {
        internal bool ValidateType(object value, Type expected)
        {
            bool result;

            if ((value != null) &&
                (value.GetType() != expected))
                result = false;
            else
                result = true;

            return result;
        }

        public override bool CanConvertTo(
            ITypeDescriptorContext ctx, Type type)
        {
            return (type == typeof(string));
        }

        public override bool CanConvertFrom(
            ITypeDescriptorContext ctx, Type type)
        {
            return (type == typeof(string));
        }

        public override object ConvertTo(
            ITypeDescriptorContext ctx, CultureInfo ci,
            object value, Type type)
        {
            ValidateType(value, typeof(TimeSpan));

            long data = (long)(((TimeSpan)value).TotalMinutes);

            return data.ToString(CultureInfo.InvariantCulture);
        }

        public override object ConvertFrom(
            ITypeDescriptorContext ctx, CultureInfo ci, object data)
        {

            long min = long.Parse((string)data,
                CultureInfo.InvariantCulture);

            return TimeSpan.FromMinutes((double)min);
        }
    }

    class UsingConfigutationConverterBase
    {

        // Create a custom section. 
        static void CreateSection()
        {
            try
            {

                CustomSection customSection;

                // Get the current configuration file.
                System.Configuration.Configuration config =
                        ConfigurationManager.OpenExeConfiguration(
                        ConfigurationUserLevel.None);

                // Create the section entry   
                // in the <configSections> and the  
                // related target section in <configuration>. 
                if (config.Sections["CustomSection"] == null)
                {
                    customSection = new CustomSection();
                    config.Sections.Add("CustomSection", customSection);
                    customSection.SectionInformation.ForceSave = true;
                    config.Save(ConfigurationSaveMode.Full);
                }
            }
            catch (ConfigurationErrorsException err)
            {
                Console.WriteLine(err.ToString());
            }

        }


        // Change custom section and write it to disk. 
        static void SerializeCustomSection()
        {
            try
            {
                System.Configuration.Configuration config =
                    ConfigurationManager.OpenExeConfiguration(
                    ConfigurationUserLevel.None);

                CustomSection customSection =
                    config.Sections.Get("CustomSection")
                    as CustomSection;

                TimeSpan ts =
                    new TimeSpan(1, 30, 30);

                customSection.MaxIdleTime = ts;

                config.Save();

                string maxIdleTime =
                    customSection.MaxIdleTime.ToString();

                Console.WriteLine("New max idle time: {0}",
                    maxIdleTime);
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }

        }

        // Read custom section from disk. 
        static void DeserializeCustomSection()
        {

            try
            {
                System.Configuration.Configuration config =
                    ConfigurationManager.OpenExeConfiguration(
                    ConfigurationUserLevel.None);

                CustomSection customSection =
                    config.Sections.Get("CustomSection")
                    as CustomSection;

                TimeSpan maxIdleTime =
                    customSection.MaxIdleTime;


                Console.WriteLine("Max idle time: {0}",
                    maxIdleTime.ToString());
            }
            catch (Exception e)
            {
                Console.WriteLine(e.ToString());
            }

        }


        static void Main(string[] args)
        {
            CreateSection();
            SerializeCustomSection();
            DeserializeCustomSection();

        }
    }
}

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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