Attribute Constructeur

Définition

Espace de noms:

System

Assemblys:

netstandard.dll, System.Runtime.dll

Source:

Attribute.cs

Initialise une nouvelle instance de la classe Attribute.

C#

protected Attribute();

Exemples

L’exemple de code suivant montre la définition d’une classe de paramètre Attribute personnalisée avec son constructeur.

C#

// Define a custom parameter attribute that takes a single message argument.
[AttributeUsage( AttributeTargets.Parameter )]
public class ArgumentUsageAttribute : Attribute
{
    // This is the attribute constructor.
    public ArgumentUsageAttribute( string UsageMsg )
    {
        this.usageMsg = UsageMsg;
    }

    // usageMsg is storage for the attribute message.
    protected string usageMsg;

    // This is the Message property for the attribute.
    public string Message
    {
        get { return usageMsg; }
        set { usageMsg = value; }
    }
}

F#

// Define a custom parameter attribute that takes a single message argument.
[<AttributeUsage(AttributeTargets.Parameter); AllowNullLiteral>]
type ArgumentUsageAttribute(usageMsg) =
    inherit Attribute()
    
    // This is the Message property for the attribute.
    member val Message = usageMsg with get, set

VB

' Define a custom parameter attribute that takes a single message argument.
<AttributeUsage(AttributeTargets.Parameter)>  _
Public Class ArgumentUsageAttribute
    Inherits Attribute
       
    ' This is the attribute constructor.
    Public Sub New(UsageMsg As String)
        Me.usageMsg = UsageMsg
    End Sub

    ' usageMsg is storage for the attribute message.
    Protected usageMsg As String
       
    ' This is the Message property for the attribute.
    Public Property Message() As String
        Get
            Return usageMsg
        End Get
        Set
            usageMsg = value
        End Set
    End Property
End Class

Remarques

Ce constructeur est uniquement appelé par les classes qui dérivent de Attribute.

S’applique à