通过

ConfigurationElement 类

  • 参考

定义

命名空间:
System.Configuration
程序集:
System.Configuration.ConfigurationManager.dll
程序集:
System.Configuration.dll
包:
System.Configuration.ConfigurationManager v8.0.1
包:
System.Configuration.ConfigurationManager v9.0.0-rc.2.24473.5
Source:
ConfigurationElement.cs
Source:
ConfigurationElement.cs
Source:
ConfigurationElement.cs
Source:
ConfigurationElement.cs
Source:
ConfigurationElement.cs

表示配置文件中的配置元素。

public ref class ConfigurationElement abstract
public abstract class ConfigurationElement
type ConfigurationElement = class
Public MustInherit Class ConfigurationElement
继承
Object
ConfigurationElement
派生

示例

下面的代码示例演示如何将自定义实现为自定义 ConfigurationElement 节中的单个元素，以及作为自定义节中的元素集合。 该示例由以下文件组成：

  • 包含名为 MyUrls的自定义节的 app.config 文件。 本节包含一个简单元素， (它不包含) 的任何其他元素和元素集合。 简单元素命名 simple 为 ，集合名为 urls。

  • 控制台应用程序。 应用程序读取 app.config 文件的内容，并将信息写入控制台。 它使用派生自 ConfigurationElement、 ConfigurationElementCollection和 ConfigurationSection的类。

  • 派生自 类的名为 UrlsSection 的 ConfigurationSection 类。 此类用于访问 MyUrls 配置文件中的 节。

  • 派生自 类的名为 UrlsCollection 的 ConfigurationElementCollection 类。 此类用于访问 urls 配置文件中的 集合。

  • 派生自 类的名为 UrlConfigElement 的 ConfigurationElement 类。 此类用于访问 simple 配置文件中的 元素和集合的成员 urls 。

若要运行该示例，请执行以下步骤：

  1. 创建具有控制台应用程序项目和名为 ConfigurationElement的类库项目的解决方案。

  2. 将三个类文件放在类库项目中，并将其他文件放在控制台库项目中。

  3. 在这两个项目中都设置对 的 System.Configuration引用。

  4. 在控制台应用程序项目中，设置对类库项目的项目引用。

// Set Assembly name to ConfigurationElement
using System;
using System.Configuration;
using System.Collections;

namespace Samples.AspNet
{
    // Entry point for console application that reads the 
    // app.config file and writes to the console the 
    // URLs in the custom section.  
    class TestConfigurationElement
    {
        static void Main(string[] args)
        {
            // Get current configuration file.
            System.Configuration.Configuration config =
                ConfigurationManager.OpenExeConfiguration(
                ConfigurationUserLevel.None);

            // Get the MyUrls section.
            UrlsSection myUrlsSection =
                config.GetSection("MyUrls") as UrlsSection;

            if (myUrlsSection == null)
            {
                Console.WriteLine("Failed to load UrlsSection.");
            }
            else
            {
                Console.WriteLine("The 'simple' element of app.config:");
                Console.WriteLine("  Name={0} URL={1} Port={2}",
                    myUrlsSection.Simple.Name,
                    myUrlsSection.Simple.Url,
                    myUrlsSection.Simple.Port);

                Console.WriteLine("The urls collection of app.config:");
                for (int i = 0; i < myUrlsSection.Urls.Count; i++)
                {
                    Console.WriteLine("  Name={0} URL={1} Port={2}",
                        myUrlsSection.Urls[i].Name,
                        myUrlsSection.Urls[i].Url,
                        myUrlsSection.Urls[i].Port);
                }
            }
            Console.ReadLine();
        }
    }
}

' Set Assembly name to ConfigurationElement
' and set Root namespace to Samples.AspNet
Imports System.Configuration
Imports System.Collections

Class TestConfigurationElement
    ' Entry point for console application that reads the 
    ' app.config file and writes to the console the 
    ' URLs in the custom section.
    Shared Sub Main(ByVal args() As String)
        ' Get the current configuration file.
        Dim config As System.Configuration.Configuration = _
            ConfigurationManager.OpenExeConfiguration( _
            ConfigurationUserLevel.None)

        ' Get the MyUrls section.
        Dim myUrlsSection As UrlsSection = _
            config.GetSection("MyUrls")

        If myUrlsSection Is Nothing Then
            Console.WriteLine("Failed to load UrlsSection.")
        Else
            Console.WriteLine("The 'simple' element of app.config:")
            Console.WriteLine("  Name={0} URL={1} Port={2}", _
                myUrlsSection.Simple.Name, _
                myUrlsSection.Simple.Url, _
                myUrlsSection.Simple.Port)
            Console.WriteLine("The urls collection of app.config:")
            Dim i As Integer
            For i = 0 To myUrlsSection.Urls.Count - 1
                Console.WriteLine("  Name={0} URL={1} Port={2}", _
                i, myUrlsSection.Urls(i).Name, _
                myUrlsSection.Urls(i).Url, _
                myUrlsSection.Urls(i).Port)
            Next i
        End If
        Console.ReadLine()
    End Sub
End Class

using System;
using System.Configuration;
using System.Collections;

namespace Samples.AspNet
{
    // Define a custom section containing an individual
    // element and a collection of elements.
    public class UrlsSection : ConfigurationSection
    {
        [ConfigurationProperty("name", 
            DefaultValue = "MyFavorites",
            IsRequired = true, 
            IsKey = false)]
        [StringValidator(InvalidCharacters = 
            " ~!@#$%^&*()[]{}/;'\"|\\",
            MinLength = 1, MaxLength = 60)]
        public string Name
        {

            get
            {
                return (string)this["name"];
            }
            set
            {
                this["name"] = value;
            }
        }

        // Declare an element (not in a collection) of the type
        // UrlConfigElement. In the configuration
        // file it corresponds to <simple .... />.
        [ConfigurationProperty("simple")]
        public UrlConfigElement Simple
        {
            get
            {
                UrlConfigElement url =
                (UrlConfigElement)base["simple"];
                return url;
            }
        }

        // Declare a collection element represented 
        // in the configuration file by the sub-section
        // <urls> <add .../> </urls> 
        // Note: the "IsDefaultCollection = false" 
        // instructs the .NET Framework to build a nested 
        // section like <urls> ...</urls>.
        [ConfigurationProperty("urls",
            IsDefaultCollection = false)]
        public UrlsCollection Urls
        {
            get
            {
                UrlsCollection urlsCollection =
                (UrlsCollection)base["urls"];
                return urlsCollection;
            }
        }

        protected override void DeserializeSection(
            System.Xml.XmlReader reader)
        {
            base.DeserializeSection(reader);
            // You can add custom processing code here.
        }

        protected override string SerializeSection(
            ConfigurationElement parentElement,
            string name, ConfigurationSaveMode saveMode)
        {
            string s =
                base.SerializeSection(parentElement,
                name, saveMode);
            // You can add custom processing code here.
            return s;
        }
    }
}

Imports System.Configuration
Imports System.Collections

' Define a custom section containing an individual
' element and a collection of elements.
Public Class UrlsSection
    Inherits ConfigurationSection

    <ConfigurationProperty("name", _
        DefaultValue:="MyFavorites", _
        IsRequired:=True, _
        IsKey:=False), _
        StringValidator( _
        InvalidCharacters:=" ~!@#$%^&*()[]{}/;'""|\", _
        MinLength:=1, MaxLength:=60)> _
        Public Property Name() As String

        Get
            Return CStr(Me("name"))
        End Get
        Set(ByVal value As String)
            Me("name") = value
        End Set
    End Property
    
    ' Declare an element (not in a collection) of the type
    ' UrlConfigElement. In the configuration
    ' file it corresponds to <simple .... />.
    <ConfigurationProperty("simple")> _
        Public ReadOnly Property Simple() _
        As UrlConfigElement

        Get
            Dim url As UrlConfigElement = _
                CType(Me("simple"),  _
                UrlConfigElement)
            Return url
        End Get
    End Property
    
    ' Declare a collection element represented 
    ' in the configuration file by the sub-section
    ' <urls> <add .../> </urls> 
    ' Note: the "IsDefaultCollection = false" 
    ' instructs the .NET Framework to build a nested 
    ' section like <urls> ...</urls>.
    <ConfigurationProperty("urls", _
        IsDefaultCollection:=False)> _
        Public ReadOnly Property Urls() _
        As UrlsCollection

        Get
            Dim urlsCollection _
                As UrlsCollection = _
                CType(Me("urls"), UrlsCollection)
            Return urlsCollection
        End Get
    End Property

    Protected Overrides Sub DeserializeSection( _
        ByVal reader As System.Xml.XmlReader)

        MyBase.DeserializeSection(reader)
        ' Enter your custom processing code here.
    End Sub

    Protected Overrides Function SerializeSection( _
        ByVal parentElement As ConfigurationElement, _
        ByVal name As String, _
        ByVal saveMode As ConfigurationSaveMode) As String

        Dim s As String = _
            MyBase.SerializeSection(parentElement, _
            name, saveMode)
        ' Enter your custom processing code here.
        Return s
    End Function 'SerializeSection
End Class

using System;
using System.Configuration;
using System.Collections;

namespace Samples.AspNet
{
    public class UrlsCollection : ConfigurationElementCollection
    {
        public UrlsCollection()
        {
            // Add one url to the collection.  This is
            // not necessary; could leave the collection 
            // empty until items are added to it outside
            // the constructor.
            UrlConfigElement url = 
                (UrlConfigElement)CreateNewElement();
            Add(url);
        }

        public override 
            ConfigurationElementCollectionType CollectionType
        {
            get
            {
                return 

                    ConfigurationElementCollectionType.AddRemoveClearMap;
            }
        }

        protected override 
            ConfigurationElement CreateNewElement()
        {
            return new UrlConfigElement();
        }

        protected override 
            ConfigurationElement CreateNewElement(
            string elementName)
        {
            return new UrlConfigElement(elementName);
        }

        protected override Object 
            GetElementKey(ConfigurationElement element)
        {
            return ((UrlConfigElement)element).Name;
        }

        public new string AddElementName
        {
            get
            { return base.AddElementName; }

            set
            { base.AddElementName = value; }
        }

        public new string ClearElementName
        {
            get
            { return base.ClearElementName; }

            set
            { base.ClearElementName = value; }
        }

        public new string RemoveElementName
        {
            get
            { return base.RemoveElementName; }
        }

        public new int Count
        {
            get { return base.Count; }
        }

        public UrlConfigElement this[int index]
        {
            get
            {
                return (UrlConfigElement)BaseGet(index);
            }
            set
            {
                if (BaseGet(index) != null)
                {
                    BaseRemoveAt(index);
                }
                BaseAdd(index, value);
            }
        }

        new public UrlConfigElement this[string Name]
        {
            get
            {
                return (UrlConfigElement)BaseGet(Name);
            }
        }

        public int IndexOf(UrlConfigElement url)
        {
            return BaseIndexOf(url);
        }

        public void Add(UrlConfigElement url)
        {
            BaseAdd(url);
            // Add custom code here.
        }

        protected override void 
            BaseAdd(ConfigurationElement element)
        {
            BaseAdd(element, false);
            // Add custom code here.
        }

        public void Remove(UrlConfigElement url)
        {
            if (BaseIndexOf(url) >= 0)
                BaseRemove(url.Name);
        }

        public void RemoveAt(int index)
        {
            BaseRemoveAt(index);
        }

        public void Remove(string name)
        {
            BaseRemove(name);
        }

        public void Clear()
        {
            BaseClear();
            // Add custom code here.
        }
    }
}

Imports System.Configuration
Imports System.Collections

Public Class UrlsCollection
    Inherits ConfigurationElementCollection

    Public Sub New()
        ' Add one url to the collection.  This is
        ' not necessary; could leave the collection 
        ' empty until items are added to it outside
        ' the constructor.
        Dim url As UrlConfigElement = _
            CType(CreateNewElement(), UrlConfigElement)
        ' Add the element to the collection.
        Add(url)
    End Sub

    Public Overrides ReadOnly Property CollectionType() _
        As ConfigurationElementCollectionType

        Get
            Return ConfigurationElementCollectionType.AddRemoveClearMap
        End Get
    End Property

    Protected Overloads Overrides Function CreateNewElement() _
        As ConfigurationElement

        Return New UrlConfigElement()
    End Function 'CreateNewElement

    Protected Overloads Overrides Function CreateNewElement( _
        ByVal elementName As String) _
        As ConfigurationElement

        Return New UrlConfigElement(elementName)
    End Function 'CreateNewElement

    Protected Overrides Function GetElementKey( _
        ByVal element As ConfigurationElement) As [Object]

        Return CType(element, UrlConfigElement).Name
    End Function 'GetElementKey

    Public Shadows Property AddElementName() As String

        Get
            Return MyBase.AddElementName
        End Get

        Set(ByVal value As String)
            MyBase.AddElementName = value
        End Set
    End Property

    Public Shadows Property ClearElementName() As String
        Get
            Return MyBase.ClearElementName
        End Get

        Set(ByVal value As String)
            MyBase.ClearElementName = value
        End Set
    End Property

    Public Shadows ReadOnly Property RemoveElementName() As String
        Get
            Return MyBase.RemoveElementName
        End Get
    End Property

    Public Shadows ReadOnly Property Count() As Integer
        Get
            Return MyBase.Count
        End Get
    End Property

    Default Public Shadows Property Item( _
    ByVal index As Integer) As UrlConfigElement
        Get
            Return CType(BaseGet(index), UrlConfigElement)
        End Get

        Set(ByVal value As UrlConfigElement)
            If Not (BaseGet(index) Is Nothing) Then
                BaseRemoveAt(index)
            End If
            BaseAdd(index, value)
        End Set
    End Property

    Default Public Shadows ReadOnly Property Item( _
        ByVal Name As String) As UrlConfigElement

        Get
            Return CType(BaseGet(Name), UrlConfigElement)
        End Get
    End Property

    Public Function IndexOf( _
        ByVal url As UrlConfigElement) As Integer

        Return BaseIndexOf(url)
    End Function 'IndexOf

    Public Sub Add(ByVal url As UrlConfigElement)
        BaseAdd(url)
        ' Add custom code here.
    End Sub

    Protected Overrides Sub BaseAdd( _
    ByVal element As ConfigurationElement)
        BaseAdd(element, False)
        ' Add custom code here.
    End Sub

    Public Overloads Sub Remove( _
        ByVal url As UrlConfigElement)

        If BaseIndexOf(url) >= 0 Then
            BaseRemove(url.Name)
        End If
    End Sub

    Public Sub RemoveAt(ByVal index As Integer)
        BaseRemoveAt(index)
    End Sub

    Public Overloads Sub Remove(ByVal name As String)
        BaseRemove(name)
    End Sub

    Public Sub Clear()
        BaseClear()
    End Sub
End Class

using System;
using System.Configuration;
using System.Collections;

namespace Samples.AspNet
{
    public class UrlConfigElement : ConfigurationElement
    {
        // Constructor allowing name, url, and port to be specified.
        public UrlConfigElement(String newName,
            String newUrl, int newPort)
        {
            Name = newName;
            Url = newUrl;
            Port = newPort;
        }

        // Default constructor, will use default values as defined
        // below.
        public UrlConfigElement()
        {
        }

        // Constructor allowing name to be specified, will take the
        // default values for url and port.
        public UrlConfigElement(string elementName)
        {
            Name = elementName;
        }

        [ConfigurationProperty("name", 
            DefaultValue = "Microsoft",
            IsRequired = true, 
            IsKey = true)]
        public string Name
        {
            get
            {
                return (string)this["name"];
            }
            set
            {
                this["name"] = value;
            }
        }

        [ConfigurationProperty("url",
            DefaultValue = "http://www.microsoft.com",
            IsRequired = true)]
        [RegexStringValidator(@"\w+:\/\/[\w.]+\S*")]
        public string Url
        {
            get
            {
                return (string)this["url"];
            }
            set
            {
                this["url"] = value;
            }
        }

        [ConfigurationProperty("port",
            DefaultValue = (int)0,
            IsRequired = false)]
        [IntegerValidator(MinValue = 0,
            MaxValue = 8080, ExcludeRange = false)]
        public int Port
        {
            get
            {
                return (int)this["port"];
            }
            set
            {
                this["port"] = value;
            }
        }

        protected override void DeserializeElement(
           System.Xml.XmlReader reader, 
            bool serializeCollectionKey)
        {
            base.DeserializeElement(reader, 
                serializeCollectionKey);
            // You can your custom processing code here.
        }

        protected override bool SerializeElement(
            System.Xml.XmlWriter writer, 
            bool serializeCollectionKey)
        {
            bool ret = base.SerializeElement(writer, 
                serializeCollectionKey);
            // You can enter your custom processing code here.
            return ret;
        }

        protected override bool IsModified()
        {
            bool ret = base.IsModified();
            // You can enter your custom processing code here.
            return ret;
        }
    }
}

Imports System.Configuration
Imports System.Collections

Public Class UrlConfigElement
    Inherits ConfigurationElement

    ' Constructor allowing name, url, and port to be specified.
    Public Sub New(ByVal newName As String, _
        ByVal newUrl As String, _
        ByVal newPort As Integer)

        Name = newName
        Url = newUrl
        Port = newPort

    End Sub

    ' Default constructor, will use default values as defined
    Public Sub New()

    End Sub


    ' Constructor allowing name to be specified, will take the
    ' default values for url and port.
    Public Sub New(ByVal elementName As String)
        Name = elementName

    End Sub


    <ConfigurationProperty("name", _
        DefaultValue:="Microsoft", _
        IsRequired:=True, _
        IsKey:=True)> _
        Public Property Name() As String

        Get
            Return CStr(Me("name"))
        End Get
        Set(ByVal value As String)
            Me("name") = value
        End Set
    End Property


    <ConfigurationProperty("url", _
        DefaultValue:="http://www.microsoft.com", _
        IsRequired:=True), _
        RegexStringValidator("\w+:\/\/[\w.]+\S*")> _
        Public Property Url() As String

        Get
            Return CStr(Me("url"))
        End Get
        Set(ByVal value As String)
            Me("url") = value
        End Set
    End Property


    <ConfigurationProperty("port", _
        DefaultValue:=0, _
        IsRequired:=False), _
        IntegerValidator(MinValue:=0, _
        MaxValue:=8080, ExcludeRange:=False)> _
        Public Property Port() As Integer

        Get
            Return Fix(Me("port"))
        End Get
        Set(ByVal value As Integer)
            Me("port") = value
        End Set
    End Property


    Protected Overrides Sub DeserializeElement(ByVal reader _
        As System.Xml.XmlReader, _
        ByVal serializeCollectionKey As Boolean)

        MyBase.DeserializeElement(reader, _
            serializeCollectionKey)
        ' Enter your custom processing code here.
    End Sub

    Protected Overrides Function SerializeElement(ByVal writer _
        As System.Xml.XmlWriter, _
        ByVal serializeCollectionKey As Boolean) As Boolean

        Dim ret As Boolean = _
            MyBase.SerializeElement(writer, serializeCollectionKey)
        ' Enter your custom processing code here.
        Return ret
    End Function 'SerializeElement

    Protected Overrides Function IsModified() As Boolean
        Dim ret As Boolean = MyBase.IsModified()
        ' Enter your custom processing code here.
        Return ret

    End Function 'IsModified
End Class

注解

ConfigurationElement是一个抽象类，用于表示配置文件 (（如 Web.config) ）中的 XML 元素。 配置文件中的元素可以包含零个、一个或多个子元素。

由于 类 ConfigurationElement 被定义为抽象类，因此无法创建它的实例。 只能从派生类。 .NET Framework 包括派生自 ConfigurationElement 类的类，用于表示标准 XML 配置元素，例如 ConfigurationSection。 还可以扩展 类以 ConfigurationElement 访问自定义配置元素和节。 本主题后面包含的示例演示如何使用派生自 ConfigurationElement的自定义类访问自定义配置元素和部分。

还可以扩展标准配置类型，例如 ConfigurationElement、 ConfigurationElementCollection、 ConfigurationProperty和 ConfigurationSection。 有关详细信息，请参阅这些类的文档。

有关如何访问配置文件中的信息的详细信息，请参阅 ConfigurationManager 类和 WebConfigurationManager 类。

实施者说明

每个对象创建ConfigurationElement表示元素属性或子元素集合的 对象的内部ConfigurationPropertyCollectionConfigurationProperty集合。

不可自定义的信息和功能由 ElementInformation 属性提供的 ElementInformation 对象包含。

可以使用编程或声明性 (特性化) 编码模型创建自定义配置元素：

  • 编程模型要求为每个元素属性创建一个属性来获取或设置其值，并将其添加到基础 ConfigurationElement 基类的内部属性包。 有关如何使用此模型的示例，请参阅 ConfigurationSection 类。

  • 更简单的声明性模型（也称为特性化模型）允许您使用属性定义元素属性，然后使用属性对其进行修饰。 这些属性指示 ASP.NET 配置系统有关属性类型及其默认值的信息。 利用通过反射获取的此信息，ASP.NET 配置系统将为你创建元素属性对象并执行所需的初始化。 本主题后面所示的示例演示如何使用此模型。

构造函数

ConfigurationElement()

初始化 ConfigurationElement 类的新实例。

属性

CurrentConfiguration

获取对顶级 Configuration 实例的引用，该实例表示当前 ConfigurationElement 实例所属的配置层次结构。
ElementInformation

获取包含 ConfigurationElement 对象的不可自定义的信息和功能的 ElementInformation 对象。
ElementProperty

获取表示 ConfigurationElement 对象本身的 ConfigurationElementProperty 对象。
EvaluationContext

获取 ConfigurationElement 对象的 ContextInformation 对象。
HasContext

获取一个值，该值指示 CurrentConfiguration 属性是否为 null。
Item[ConfigurationProperty]

获取或设置此配置元素的属性或特性。
Item[String]

获取或设置此配置元素的属性、特性或子元素。
LockAllAttributesExcept

获取被锁定的特性的集合。
LockAllElementsExcept

获取被锁定的元素的集合。
LockAttributes

获取被锁定的特性的集合。
LockElements

获取被锁定的元素的集合。
LockItem

获取或设置一个值，该值指示是否已锁定该元素。
Properties

获取属性的集合。

方法

DeserializeElement(XmlReader, Boolean)

从配置文件读取 XML。
Equals(Object)

将当前的 ConfigurationElement 实例与指定的对象进行比较。
GetHashCode()

获取表示当前 ConfigurationElement 实例的唯一值。
GetTransformedAssemblyString(String)

返回指定程序集名称的转换版本。
GetTransformedTypeString(String)

返回指定类型名称的转换版本。
GetType()

获取当前实例的 Type。

(继承自 Object)
Init()

将 ConfigurationElement 对象设置为其初始状态。
InitializeDefault()

用于初始化 ConfigurationElement 对象的默认值集。
IsModified()

指示自上次保存或加载该配置元素后并在派生类中实现该元素时，该元素是否已被修改。
IsReadOnly()

获取一个值，该值指示 ConfigurationElement 对象是否为只读。
ListErrors(IList)

将此 ConfigurationElement 对象以及所有子元素中无效属性的错误添加到传递的列表中。
MemberwiseClone()

创建当前 Object 的浅表副本。

(继承自 Object)
OnDeserializeUnrecognizedAttribute(String, String)

获取一个值，该值指示反序列化过程中是否遇到未知特性。
OnDeserializeUnrecognizedElement(String, XmlReader)

获取一个值，该值指示反序列化过程中是否遇到未知元素。
OnRequiredPropertyNotFound(String)

找不到所需属性时引发异常。
PostDeserialize()

反序列化后调用。
PreSerialize(XmlWriter)

在序列化之前调用。
Reset(ConfigurationElement)

重置 ConfigurationElement 对象的内部状态，包括锁和属性集合。
ResetModified()

在派生类中实现时，将 IsModified() 方法的值重置为 false。
SerializeElement(XmlWriter, Boolean)

当在派生类中实现后，将此配置元素的内容写入配置文件。
SerializeToXmlElement(XmlWriter, String)

当在派生类中实现后，将此配置元素的外部标记写入配置文件。
SetPropertyValue(ConfigurationProperty, Object, Boolean)

将属性设置为指定值。
SetReadOnly()

设置 ConfigurationElement 对象及所有子元素的 IsReadOnly() 属性。
ToString()

返回表示当前对象的字符串。

(继承自 Object)
Unmerge(ConfigurationElement, ConfigurationElement, ConfigurationSaveMode)

修改 ConfigurationElement 对象以移除所有不应该保存的值。

适用于

另请参阅