DesignOnlyAttribute Class

Definition

Namespace:

System.ComponentModel

Assembly:

System.ComponentModel.Primitives.dll

Source:

DesignOnlyAttribute.cs

Specifies whether a property can only be set at design time.

public ref class DesignOnlyAttribute sealed : Attribute

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

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

Public NotInheritable Class DesignOnlyAttribute
Inherits Attribute

Inheritance

Object

Attribute

DesignOnlyAttribute

Attributes

AttributeUsageAttribute

Examples

The following example creates a GetLanguage property. The property is marked with a DesignOnlyAttribute.

public:
   [DesignOnly(true)]
   property CultureInfo^ GetLanguage 
   {
      CultureInfo^ get()
      {
         // Insert code here.
         return myCultureInfo;
      }
      void set( CultureInfo^ value )
      {
         // Insert code here.
      }
   }

[DesignOnly(true)]
 public CultureInfo GetLanguage {
    get {
       // Insert code here.
       return myCultureInfo;
    }
    set {
       // Insert code here.
    }
 }

<DesignOnly(True)> _
Public Property GetLanguage() As CultureInfo
    Get
        ' Insert code here.
        Return myCultureInfo
    End Get
    Set
        ' Insert code here.
    End Set
End Property

The next example gets the value of the DesignOnlyAttribute. First the code gets a PropertyDescriptorCollection with all the properties for the object. Next it indexes into the PropertyDescriptorCollection to find the GetLanguage property. Then it returns the attributes for this property and saves them in the attributes variable.

The example then prints whether the property is design only by retrieving DesignOnlyAttribute from the AttributeCollection, and writing it to the console screen.

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

/* Prints whether the property is marked as DesignOnly 
by retrieving the DesignOnlyAttribute from the AttributeCollection. */
DesignOnlyAttribute^ myAttribute = dynamic_cast<DesignOnlyAttribute^>(attributes[ DesignOnlyAttribute::typeid ]);
Console::WriteLine( "This property is design only :{0}", myAttribute->IsDesignOnly );

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

 /* Prints whether the property is marked as DesignOnly 
  * by retrieving the DesignOnlyAttribute from the AttributeCollection. */
 DesignOnlyAttribute myAttribute = 
    (DesignOnlyAttribute)attributes[typeof(DesignOnlyAttribute)];
 Console.WriteLine("This property is design only :" +
    myAttribute.IsDesignOnly.ToString());

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

' Prints whether the property is marked as DesignOnly 
' by retrieving the DesignOnlyAttribute from the AttributeCollection.
Dim myAttribute As DesignOnlyAttribute = _
    CType(attributes(GetType(DesignOnlyAttribute)), DesignOnlyAttribute)
Console.WriteLine(("This property is design only :" & _
    myAttribute.IsDesignOnly.ToString()))

Remarks

Members marked with the DesignOnlyAttribute set to true can be set only at design time. Typically, these properties exist only at design time and do not correspond to a real property on the object at run time.

Members that either have no attribute or are marked with the DesignOnlyAttribute set to false can be set during run time. The default is false.

A property with the DesignOnlyAttribute set to true has its value serialized to the .resx file instead of the InitializeComponent method.

For more information, see Attributes.

Constructors

DesignOnlyAttribute(Boolean)

Initializes a new instance of the DesignOnlyAttribute class.

Fields

Default	Specifies the default value for the DesignOnlyAttribute, which is No. This static field is read-only.
No	Specifies that a property can be set at design time or at run time. This static field is read-only.
Yes	Specifies that a property can be set only at design time. This static field is read-only.

Properties

IsDesignOnly	Gets a value indicating whether a property can be set only at design time.
TypeId	When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute)

Methods

Equals(Object)	Returns whether the value of the given object is equal to the current DesignOnlyAttribute.
GetHashCode()	Returns the hash code for this instance.
GetType()	Gets the Type of the current instance. (Inherited from Object)
IsDefaultAttribute()	Determines if this attribute is the default.
Match(Object)	When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute)
MemberwiseClone()	Creates a shallow copy of the current Object. (Inherited from Object)
ToString()	Returns a string that represents the current object. (Inherited from Object)

See also

• Attribute
• PropertyDescriptor