ConfigurationCollectionAttribute 类

定义

以声明的方式指示 .NET 创建配置元素集合的实例。Declaratively instructs .NET to create an instance of a configuration element collection. 此类不能被继承。This class cannot be inherited.

public ref class ConfigurationCollectionAttribute sealed : Attribute
[System.AttributeUsage(System.AttributeTargets.Class | System.AttributeTargets.Property)]
public sealed class ConfigurationCollectionAttribute : Attribute
[<System.AttributeUsage(System.AttributeTargets.Class | System.AttributeTargets.Property)>]
type ConfigurationCollectionAttribute = class
    inherit Attribute
Public NotInheritable Class ConfigurationCollectionAttribute
Inherits Attribute
继承
ConfigurationCollectionAttribute
属性

示例

下面的示例演示如何使用 ConfigurationCollectionAttributeThe following example shows how to use the ConfigurationCollectionAttribute.

此示例由以下三个类组成: UrlsSectionUrlsCollectionUrlConfigElementThis example consists of three classes: UrlsSection, UrlsCollection and UrlConfigElement. UrlsSection类使用 ConfigurationCollectionAttribute 来定义自定义配置节。The UrlsSection class uses the ConfigurationCollectionAttribute to define a custom configuration section. 此部分包含由类 UrlsCollection) 定义 (url 元素的类) 定义的 url 集合 (UrlConfigElementThis section contains a URL collection (defined by the UrlsCollection class) of URL elements (defined by the UrlConfigElement class). 运行该示例时, UrlsSection 会创建类的一个实例,并在应用程序配置文件中生成以下配置元素:When you run the example, an instance of the UrlsSection class is created and the following configuration elements are generated in the application configuration file:

<configuration>  
    <configSections>  
        <section name="MyUrls" type="UrlsSection,   
          ConfigurationCollectionAttribute, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null" />  
    </configSections>  
    <MyUrls>  
        <urls>  
            <remove name="Contoso" />  
            <add name="Contoso" url="http://www.contoso.com" port="0" />  
        </urls>  
    </MyUrls>  
</configuration  

using System;
using System.Configuration;

// Define a custom section that contains a custom
// UrlsCollection collection of custom UrlConfigElement elements.
// This class shows how to use the ConfigurationCollectionAttribute.
public class UrlsSection : ConfigurationSection
{
    // Declare the Urls collection property using the
    // ConfigurationCollectionAttribute.
    // This allows to build a nested section that contains
    // a collection of elements.
    [ConfigurationProperty("urls", IsDefaultCollection = false)]
    [ConfigurationCollection(typeof(UrlsCollection),
        AddItemName = "add",
        ClearItemsName = "clear",
        RemoveItemName = "remove")]
    public UrlsCollection Urls
    {
        get
        {
            UrlsCollection urlsCollection =
                (UrlsCollection)base["urls"];
            return urlsCollection;
        }
    }
}

// Define the custom UrlsCollection that contains the 
// custom UrlsConfigElement elements.
public class UrlsCollection : ConfigurationElementCollection
{
    public UrlsCollection()
    {
        UrlConfigElement url = (UrlConfigElement)CreateNewElement();
        Add(url);
    }

    public override ConfigurationElementCollectionType CollectionType
    {
        get
        {
            return ConfigurationElementCollectionType.AddRemoveClearMap;
        }
    }

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

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

    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);
    }
    protected override void BaseAdd(ConfigurationElement element)
    {
        BaseAdd(element, false);
    }

    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();
    }
}

// Define the custom UrlsConfigElement elements that are contained 
// by the custom UrlsCollection.
// Notice that you can change the default values to create new default elements.
public class UrlConfigElement : ConfigurationElement
{
    public UrlConfigElement(String name, String url)
    {
        this.Name = name;
        this.Url = url;
    }

    public UrlConfigElement()
    {

        this.Name = "Contoso";
        this.Url = "http://www.contoso.com";
        this.Port = 0;
    }

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

    [ConfigurationProperty("url", DefaultValue = "http://www.contoso.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;
        }
    }
}


Imports System.Configuration




' Define a custom section that contains a custom
' UrlsCollection collection of custom UrlConfigElement elements.
' This class shows how to use the ConfigurationCollectionAttribute.
Public Class UrlsSection
    Inherits ConfigurationSection
    ' Declare the Urls collection property using the
    ' ConfigurationCollectionAttribute.
    ' This allows to build a nested section that contains
    ' a collection of elements.
    <ConfigurationProperty("urls", IsDefaultCollection:=False),
        System.Configuration.ConfigurationCollection(GetType(UrlsCollection),
        AddItemName:="add", ClearItemsName:="clear", RemoveItemName:="remove")> _
    Public ReadOnly Property Urls() As UrlsCollection
        Get
            Dim urlsCollection As UrlsCollection = CType(MyBase.Item("urls"), UrlsCollection)
            Return urlsCollection
        End Get
    End Property

End Class

' Define the custom UrlsCollection that contains the 
' custom UrlsConfigElement elements.
Public Class UrlsCollection
    Inherits ConfigurationElementCollection
    Public Sub New()
        Dim url As UrlConfigElement = CType(CreateNewElement(), UrlConfigElement)
        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

    Protected Overrides Function GetElementKey(ByVal element As ConfigurationElement) As Object
        Return (CType(element, UrlConfigElement)).Name
    End Function

    Default Shadows Property Item(ByVal index As Integer) As UrlConfigElement
        Get
            Return CType(BaseGet(index), UrlConfigElement)
        End Get
        Set(ByVal value As UrlConfigElement)
            If BaseGet(index) IsNot 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

    Public Sub Add(ByVal url As UrlConfigElement)
        BaseAdd(url)
    End Sub
    Protected Overloads Overrides Sub BaseAdd(ByVal element As ConfigurationElement)
        BaseAdd(element, False)
    End Sub

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

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

' Define the custom UrlsConfigElement elements that are contained 
' by the custom UrlsCollection.
Public Class UrlConfigElement
    Inherits ConfigurationElement
    Public Sub New(ByVal name As String, ByVal url As String)
        Me.Name = name
        Me.Url = url
    End Sub

    Public Sub New()
        Me.Name = "Contoso"
        Me.Url = "http://www.contoso.com"
        Me.Port = 0
    End Sub

    <ConfigurationProperty("name", DefaultValue:="Contoso", 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.contoso.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 CInt(Fix(Me("port")))
        End Get
        Set(ByVal value As Integer)
            Me("port") = value
        End Set
    End Property
End Class

using System;
using System.Configuration;

class UsingConfigurationCollectionAttribute
{

    // Create a custom section and save it in the 
    // application configuration file.
    static void CreateCustomSection()
    {
        try
        {

            // Create a custom configuration section.
            UrlsSection myUrlsSection = new UrlsSection();

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

            // Add the custom section to the application
            // configuration file.
            if (config.Sections["MyUrls"] == null)
            {
                config.Sections.Add("MyUrls", myUrlsSection);
            }

            // Save the application configuration file.
            myUrlsSection.SectionInformation.ForceSave = true;
            config.Save(ConfigurationSaveMode.Modified);

            Console.WriteLine("Created custom section in the application configuration file: {0}",
                config.FilePath);
            Console.WriteLine();
        }
        catch (ConfigurationErrorsException err)
        {
            Console.WriteLine("CreateCustomSection: {0}", err.ToString());
        }
    }

    static void ReadCustomSection()
    {
        try
        {
            // Get the application configuration file.
            System.Configuration.Configuration config =
                    ConfigurationManager.OpenExeConfiguration(
                    ConfigurationUserLevel.None) as Configuration;

            // Read and display the custom section.
            UrlsSection myUrlsSection =
               ConfigurationManager.GetSection("MyUrls") as UrlsSection;

            if (myUrlsSection == null)
            {
                Console.WriteLine("Failed to load UrlsSection.");
            }
            else
            {
                Console.WriteLine("URLs defined in the configuration file:");
                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);
                }
            }
        }
        catch (ConfigurationErrorsException err)
        {
            Console.WriteLine("ReadCustomSection(string): {0}", err.ToString());
        }
    }
    
    static void Main(string[] args)
    {
       
        // Get the name of the application.
        string appName =
            Environment.GetCommandLineArgs()[0];

        // Create a custom section and save it in the 
        // application configuration file.
        CreateCustomSection();

        // Read the custom section saved in the
        // application configuration file.
        ReadCustomSection();

        Console.WriteLine();
        Console.WriteLine("Enter any key to exit.");

        Console.ReadLine();
    }
}
Imports System.Configuration


Friend Class UsingConfigurationCollectionAttribute

    ' Create a custom section and save it in the 
    ' application configuration file.
    Private Shared Sub CreateCustomSection()
        Try

            ' Create a custom configuration section.
            Dim myUrlsSection As New UrlsSection()

            ' Get the current configuration file.
            Dim config As System.Configuration.Configuration =
                ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None)

            ' Add the custom section to the application
            ' configuration file.
            If config.Sections("MyUrls") Is Nothing Then
                config.Sections.Add("MyUrls", myUrlsSection)
            End If


            ' Save the application configuration file.
            myUrlsSection.SectionInformation.ForceSave = True
            config.Save(ConfigurationSaveMode.Modified)

            Console.WriteLine("Created custom section in the application configuration file: {0}", config.FilePath)
            Console.WriteLine()

        Catch err As ConfigurationErrorsException
            Console.WriteLine("CreateCustomSection: {0}", err.ToString())
        End Try

    End Sub

    Private Shared Sub ReadCustomSection()
        Try
            ' Get the application configuration file.
            Dim config As System.Configuration.Configuration = TryCast(ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None), Configuration)

            ' Read and display the custom section.
            Dim myUrlsSection As UrlsSection = TryCast(ConfigurationManager.GetSection("MyUrls"), UrlsSection)

            If myUrlsSection Is Nothing Then
                Console.WriteLine("Failed to load UrlsSection.")
            Else
                Console.WriteLine("URLs defined in app.config:")
                For i As Integer = 0 To myUrlsSection.Urls.Count - 1
                    Console.WriteLine("  Name={0} URL={1} Port={2}", myUrlsSection.Urls(i).Name, myUrlsSection.Urls(i).Url, myUrlsSection.Urls(i).Port)
                Next i
            End If
        Catch err As ConfigurationErrorsException
            Console.WriteLine("ReadCustomSection(string): {0}", err.ToString())
        End Try

    End Sub

    Shared Sub Main(ByVal args() As String)

        ' Get the name of the application.
        Dim appName As String = Environment.GetCommandLineArgs()(0)

        ' Create a custom section and save it in the 
        ' application configuration file.
        CreateCustomSection()

        ' Read the custom section saved in the
        ' application configuration file.
        ReadCustomSection()

        Console.WriteLine()
        Console.WriteLine("Enter any key to exit.")

        Console.ReadLine()
    End Sub
End Class

注解

使用 ConfigurationCollectionAttribute 特性修饰 ConfigurationElementCollection 元素。You use the ConfigurationCollectionAttribute attribute to decorate a ConfigurationElementCollection element. 这会指示 .NET 创建集合的实例并使用自定义值对其进行初始化 ConfigurationElementThis instructs .NET to create an instance of the collection and to initialize it using your custom ConfigurationElement values.

备注

若要创建自定义配置元素,最简单的方法是使用特性化 (声明性) 模型。The simplest way to create a custom configuration element is to use the attributed (declarative) model. 声明元素并用特性修饰它们 ConfigurationCollectionAttributeYou declare the elements and decorate them with the ConfigurationCollectionAttribute attribute. 对于标记为此属性的每个元素,.NET 使用反射来读取修饰参数并创建相关 ConfigurationElementCollection 实例。For each element marked with this attribute, .NET uses reflection to read the decorating parameters and create a related ConfigurationElementCollection instance. 你还可以使用编程模型。You can also use the programmatic model. 在这种情况下,你负责声明自定义公共集合,同时还需要重写该 ConfigurationElementCollection 成员并返回 properties 集合。In this case it is your responsibility to declare the custom public collection but also to override the ConfigurationElementCollection member and return the properties collection.

.NET 配置系统提供了您在创建自定义配置元素期间可以使用的属性类型。The .NET configuration system provides attribute types that you can use during the creation of custom configuration elements. 有两种类型的属性:There are two kinds of attributes:

构造函数

ConfigurationCollectionAttribute(Type)

初始化 ConfigurationCollectionAttribute 类的新实例。Initializes a new instance of the ConfigurationCollectionAttribute class.

属性

AddItemName

获取或设置 <add> 配置元素的名称。Gets or sets the name of the <add> configuration element.

ClearItemsName

获取或设置 <clear> 配置元素的名称。Gets or sets the name for the <clear> configuration element.

CollectionType

获取或设置 ConfigurationCollectionAttribute 特性的类型。Gets or sets the type of the ConfigurationCollectionAttribute attribute.

ItemType

获取集合元素的类型。Gets the type of the collection element.

RemoveItemName

获取或设置 <remove> 配置元素的名称。Gets or sets the name for the <remove> configuration element.

TypeId

在派生类中实现时,获取此 Attribute 的唯一标识符。When implemented in a derived class, gets a unique identifier for this Attribute.

(继承自 Attribute)

方法

Equals(Object)

返回一个值,该值指示此实例是否与指定的对象相等。Returns a value that indicates whether this instance is equal to a specified object.

(继承自 Attribute)
GetHashCode()

返回此实例的哈希代码。Returns the hash code for this instance.

(继承自 Attribute)
GetType()

获取当前实例的 TypeGets the Type of the current instance.

(继承自 Object)
IsDefaultAttribute()

在派生类中重写时,指示此实例的值是否是派生类的默认值。When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.

(继承自 Attribute)
Match(Object)

当在派生类中重写时,返回一个指示此实例是否等于指定对象的值。When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.

(继承自 Attribute)
MemberwiseClone()

创建当前 Object 的浅表副本。Creates a shallow copy of the current Object.

(继承自 Object)
ToString()

返回表示当前对象的字符串。Returns a string that represents the current object.

(继承自 Object)

显式接口实现

_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

将一组名称映射为对应的一组调度标识符。Maps a set of names to a corresponding set of dispatch identifiers.

(继承自 Attribute)
_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)

检索对象的类型信息,然后可以使用该信息获取接口的类型信息。Retrieves the type information for an object, which can be used to get the type information for an interface.

(继承自 Attribute)
_Attribute.GetTypeInfoCount(UInt32)

检索对象提供的类型信息接口的数量(0 或 1)。Retrieves the number of type information interfaces that an object provides (either 0 or 1).

(继承自 Attribute)
_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

提供对某一对象公开的属性和方法的访问。Provides access to properties and methods exposed by an object.

(继承自 Attribute)

适用于

另请参阅