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ConfigurationConverterBase Class

Definition

The base class for the configuration converter types.

C#
public abstract class ConfigurationConverterBase : System.ComponentModel.TypeConverter
Inheritance
ConfigurationConverterBase
Derived

Examples

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.

C#
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.

C#

    // 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.

C#
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
<?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>  

Remarks

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.

Constructors

ConfigurationConverterBase()

Initializes a new instance of the ConfigurationConverterBase class.

Methods

CanConvertFrom(ITypeDescriptorContext, Type)

Determines whether the conversion is allowed.

CanConvertFrom(Type)

Returns whether this converter can convert an object of the given type to the type of this converter.

(Inherited from TypeConverter)
CanConvertTo(ITypeDescriptorContext, Type)

Determines whether the conversion is allowed.

CanConvertTo(Type)

Returns whether this converter can convert the object to the specified type.

(Inherited from TypeConverter)
ConvertFrom(ITypeDescriptorContext, CultureInfo, Object)

Converts the given object to the type of this converter, using the specified context and culture information.

(Inherited from TypeConverter)
ConvertFrom(Object)

Converts the given value to the type of this converter.

(Inherited from TypeConverter)
ConvertFromInvariantString(ITypeDescriptorContext, String)

Converts the given string to the type of this converter, using the invariant culture and the specified context.

(Inherited from TypeConverter)
ConvertFromInvariantString(String)

Converts the given string to the type of this converter, using the invariant culture.

(Inherited from TypeConverter)
ConvertFromString(ITypeDescriptorContext, CultureInfo, String)

Converts the given text to an object, using the specified context and culture information.

(Inherited from TypeConverter)
ConvertFromString(ITypeDescriptorContext, String)

Converts the given text to an object, using the specified context.

(Inherited from TypeConverter)
ConvertFromString(String)

Converts the specified text to an object.

(Inherited from TypeConverter)
ConvertTo(ITypeDescriptorContext, CultureInfo, Object, Type)

Converts the given value object to the specified type, using the specified context and culture information.

(Inherited from TypeConverter)
ConvertTo(Object, Type)

Converts the given value object to the specified type, using the arguments.

(Inherited from TypeConverter)
ConvertToInvariantString(ITypeDescriptorContext, Object)

Converts the specified value to a culture-invariant string representation, using the specified context.

(Inherited from TypeConverter)
ConvertToInvariantString(Object)

Converts the specified value to a culture-invariant string representation.

(Inherited from TypeConverter)
ConvertToString(ITypeDescriptorContext, CultureInfo, Object)

Converts the given value to a string representation, using the specified context and culture information.

(Inherited from TypeConverter)
ConvertToString(ITypeDescriptorContext, Object)

Converts the given value to a string representation, using the given context.

(Inherited from TypeConverter)
ConvertToString(Object)

Converts the specified value to a string representation.

(Inherited from TypeConverter)
CreateInstance(IDictionary)

Re-creates an Object given a set of property values for the object.

(Inherited from TypeConverter)
CreateInstance(ITypeDescriptorContext, IDictionary)

Creates an instance of the type that this TypeConverter is associated with, using the specified context, given a set of property values for the object.

(Inherited from TypeConverter)
Equals(Object)

Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetConvertFromException(Object)

Returns an exception to throw when a conversion cannot be performed.

(Inherited from TypeConverter)
GetConvertToException(Object, Type)

Returns an exception to throw when a conversion cannot be performed.

(Inherited from TypeConverter)
GetCreateInstanceSupported()

Returns whether changing a value on this object requires a call to the CreateInstance(IDictionary) method to create a new value.

(Inherited from TypeConverter)
GetCreateInstanceSupported(ITypeDescriptorContext)

Returns whether changing a value on this object requires a call to CreateInstance(IDictionary) to create a new value, using the specified context.

(Inherited from TypeConverter)
GetHashCode()

Serves as the default hash function.

(Inherited from Object)
GetProperties(ITypeDescriptorContext, Object, Attribute[])

Returns a collection of properties for the type of array specified by the value parameter, using the specified context and attributes.

(Inherited from TypeConverter)
GetProperties(ITypeDescriptorContext, Object)

Returns a collection of properties for the type of array specified by the value parameter, using the specified context.

(Inherited from TypeConverter)
GetProperties(Object)

Returns a collection of properties for the type of array specified by the value parameter.

(Inherited from TypeConverter)
GetPropertiesSupported()

Returns whether this object supports properties.

(Inherited from TypeConverter)
GetPropertiesSupported(ITypeDescriptorContext)

Returns whether this object supports properties, using the specified context.

(Inherited from TypeConverter)
GetStandardValues()

Returns a collection of standard values from the default context for the data type this type converter is designed for.

(Inherited from TypeConverter)
GetStandardValues(ITypeDescriptorContext)

Returns a collection of standard values for the data type this type converter is designed for when provided with a format context.

(Inherited from TypeConverter)
GetStandardValuesExclusive()

Returns whether the collection of standard values returned from GetStandardValues() is an exclusive list.

(Inherited from TypeConverter)
GetStandardValuesExclusive(ITypeDescriptorContext)

Returns whether the collection of standard values returned from GetStandardValues() is an exclusive list of possible values, using the specified context.

(Inherited from TypeConverter)
GetStandardValuesSupported()

Returns whether this object supports a standard set of values that can be picked from a list.

(Inherited from TypeConverter)
GetStandardValuesSupported(ITypeDescriptorContext)

Returns whether this object supports a standard set of values that can be picked from a list, using the specified context.

(Inherited from TypeConverter)
GetType()

Gets the Type of the current instance.

(Inherited from Object)
IsValid(ITypeDescriptorContext, Object)

Returns whether the given value object is valid for this type and for the specified context.

(Inherited from TypeConverter)
IsValid(Object)

Returns whether the given value object is valid for this type.

(Inherited from TypeConverter)
MemberwiseClone()

Creates a shallow copy of the current Object.

(Inherited from Object)
SortProperties(PropertyDescriptorCollection, String[])

Sorts a collection of properties.

(Inherited from TypeConverter)
ToString()

Returns a string that represents the current object.

(Inherited from Object)

Applies to

Product Versions
.NET 8 (package-provided), 9 (package-provided)
.NET Framework 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7 (package-provided), 4.7, 4.7.1 (package-provided), 4.7.1, 4.7.2 (package-provided), 4.7.2, 4.8 (package-provided), 4.8, 4.8.1
.NET Standard 2.0 (package-provided)
Windows Desktop 3.0, 3.1, 5, 6, 7, 8, 9

See also