DescriptionAttribute Klass

Definition

public ref class DescriptionAttribute : Attribute

[System.AttributeUsage(System.AttributeTargets.All)]
public class DescriptionAttribute : Attribute

[<System.AttributeUsage(System.AttributeTargets.All)>]
type DescriptionAttribute = class
    inherit Attribute

Public Class DescriptionAttribute
Inherits Attribute

Arv

Object

Attribute

DescriptionAttribute

Härledda

Microsoft.VisualBasic.Compatibility.VB6.SRDescriptionAttribute

System.Data.DataSysDescriptionAttribute

System.Diagnostics.MonitoringDescriptionAttribute

System.DirectoryServices.DSDescriptionAttribute

System.IO.IODescriptionAttribute

Mer…

Attribut

AttributeUsageAttribute

Exempel

I följande exempel skapas egenskapen MyImage . Egenskapen har två attribut, en DescriptionAttribute och en CategoryAttribute.

public:
   property Image^ MyImage 
   {
      [Description("The image associated with the control"),Category("Appearance")]
      Image^ get()
      {
         // Insert code here.
         return image1;
      }

      void set( Image^ value )
      {
         // Insert code here.
      }
   }

[Description("The image associated with the control"), Category("Appearance")]
public Image MyImage
{
    get =>
        // Insert code here.
        image1;
    set
    {
        // Insert code here.
    }
}

<Description("The image associated with the control"), _
    Category("Appearance")> _
Public Property MyImage() As Image
    Get
        ' Insert code here.
        Return image1
    End Get
    Set
        ' Insert code here.
    End Set 
End Property

I nästa exempel hämtas beskrivningen av MyImage. Först hämtar koden en PropertyDescriptorCollection med alla egenskaper för objektet. Därefter indexerar den till PropertyDescriptorCollection för att hämta MyImage. Sedan returneras attributen för den här egenskapen och sparas i attributvariabeln.

Exemplet skriver sedan ut beskrivningen genom att DescriptionAttribute hämta från AttributeCollection, och skriva den till konsolskärmen.

// Gets the attributes for the property.
AttributeCollection^ attributes = TypeDescriptor::GetProperties( this )[ "MyImage" ]->Attributes;

/* Prints the description by retrieving the DescriptionAttribute 
      * from the AttributeCollection. */
DescriptionAttribute^ myAttribute = dynamic_cast<DescriptionAttribute^>(attributes[ DescriptionAttribute::typeid ]);
Console::WriteLine( myAttribute->Description );

// Gets the attributes for the property.
AttributeCollection attributes =
   TypeDescriptor.GetProperties(this)["MyImage"].Attributes;

/* Prints the description by retrieving the DescriptionAttribute 
 * from the AttributeCollection. */
DescriptionAttribute myAttribute =
   (DescriptionAttribute)attributes[typeof(DescriptionAttribute)];
Console.WriteLine(myAttribute.Description);

' Gets the attributes for the property.
Dim attributes As AttributeCollection = _
    TypeDescriptor.GetProperties(Me)("MyImage").Attributes

' Prints the description by retrieving the DescriptionAttribute
' from the AttributeCollection. 
Dim myAttribute As DescriptionAttribute = _
    CType(attributes(GetType(DescriptionAttribute)), DescriptionAttribute)
Console.WriteLine(myAttribute.Description)

Kommentarer

En visuell designer kan visa den angivna beskrivningen när du refererar till komponentmedlemmen, till exempel i en Properties window. Anropa Description för att komma åt värdet för det här attributet.

Mer information finns i Attribut.

Se även

• Attribute
• PropertyDescriptor
• EventDescriptor