DesignerCategoryAttribute Class (System.ComponentModel)

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DesignerCategoryAttribute Class

Specifies that the designer for a class belongs to a certain category.

Inheritance Hierarchy

System.Object
  System.Attribute
    System.ComponentModel.DesignerCategoryAttribute

Namespace:  System.ComponentModel
Assembly:  System (in System.dll)
Syntax

Visual Basic
<AttributeUsageAttribute(AttributeTargets.Class, AllowMultiple := False, Inherited := True)> _
Public NotInheritable Class DesignerCategoryAttribute _
	Inherits Attribute
C#
[AttributeUsageAttribute(AttributeTargets.Class, AllowMultiple = false, Inherited = true)]
public sealed class DesignerCategoryAttribute : Attribute
Visual C++
[AttributeUsageAttribute(AttributeTargets::Class, AllowMultiple = false, Inherited = true)]
public ref class DesignerCategoryAttribute sealed : public Attribute
F#
[<Sealed>]
[<AttributeUsageAttribute(AttributeTargets.Class, AllowMultiple = false, Inherited = true)>]
type DesignerCategoryAttribute =  
    class
        inherit Attribute
    end

The DesignerCategoryAttribute type exposes the following members.

Constructors

  Name Description
Public method Supported by the XNA Framework DesignerCategoryAttribute() Initializes a new instance of the DesignerCategoryAttribute class with an empty string ("").
Public method Supported by the XNA Framework DesignerCategoryAttribute(String) Initializes a new instance of the DesignerCategoryAttribute class with the given category name.
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Properties

  Name Description
Public property Supported by the XNA Framework Category Gets the name of the category.
Public property TypeId Infrastructure. Gets a unique identifier for this attribute. (Overrides Attribute.TypeId.)
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Methods

  Name Description
Public method Supported by the XNA Framework Equals Infrastructure. Returns whether the value of the given object is equal to the current DesignOnlyAttribute. (Overrides Attribute.Equals(Object).)
Protected method Supported by the XNA Framework Finalize Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public method Supported by the XNA Framework GetHashCode Infrastructure. Returns the hash code for this instance. (Overrides Attribute.GetHashCode().)
Public method Supported by the XNA Framework GetType Gets the Type of the current instance. (Inherited from Object.)
Public method IsDefaultAttribute Infrastructure. Determines if this attribute is the default. (Overrides Attribute.IsDefaultAttribute().)
Public method Supported by the XNA Framework Match When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.)
Protected method Supported by the XNA Framework MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
Public method Supported by the XNA Framework ToString Returns a string that represents the current object. (Inherited from Object.)
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Fields

  Name Description
Public field Static member Supported by the XNA Framework Component Specifies that a component marked with this category use a component designer. This field is read-only.
Public field Static member Supported by the XNA Framework Default Infrastructure. Specifies that a component marked with this category cannot use a visual designer. This static field is read-only.
Public field Static member Supported by the XNA Framework Form Specifies that a component marked with this category use a form designer. This static field is read-only.
Public field Static member Supported by the XNA Framework Generic Specifies that a component marked with this category use a generic designer. This static field is read-only.
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Explicit Interface Implementations

  Name Description
Explicit interface implemetation Private method _Attribute.GetIDsOfNames Maps a set of names to a corresponding set of dispatch identifiers. (Inherited from Attribute.)
Explicit interface implemetation Private method _Attribute.GetTypeInfo Retrieves the type information for an object, which can be used to get the type information for an interface. (Inherited from Attribute.)
Explicit interface implemetation Private method _Attribute.GetTypeInfoCount Retrieves the number of type information interfaces that an object provides (either 0 or 1). (Inherited from Attribute.)
Explicit interface implemetation Private method _Attribute.Invoke Provides access to properties and methods exposed by an object. (Inherited from Attribute.)
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Remarks

A visual designer can use a designer category to inform a development environment of the type of designer that will be implemented. If no designer category is provided on a class, a development environment may or may not allow the class to be designed. A category can be created for any name.

When you mark a class with this attribute, it is set to a constant member. When you want to check the value of this attribute in your code, you must specify the constant member. The Description column in the table below lists the constant member that each value is set to.

The DesignerCategoryAttribute class defines the following common categories:

Category

Description

Component

Designers that are used with components. The attribute is set to the constant member DesignerCategoryAttribute.Component.

Form

Designers that are used with forms. The attribute is set to the constant member DesignerCategoryAttribute.Form.

Designer

Designers that are used with designers. The attribute is set to the constant member DesignerCategoryAttribute.Generic.

Empty String ("")

This is the default category.

For more information, see Extending Metadata Using Attributes.

Examples

The following example creates a class called MyForm. MyForm has two attributes, a DesignerAttribute that specifies this class uses the DocumentDesigner, and a DesignerCategoryAttribute that specifies the Form category.

Visual Basic

<Designer("System.Windows.Forms.Design.DocumentDesigner, System.Windows.Forms.Design", _
    GetType(IRootDesigner)), DesignerCategory("Form")> _
Public Class MyForm

    Inherits ContainerControl
    ' Insert code here.
End Class 'MyForm


C#

[Designer("System.Windows.Forms.Design.DocumentDesigner, System.Windows.Forms.Design", 
    typeof(IRootDesigner)),
    DesignerCategory("Form")]

 public class MyForm : ContainerControl {
    // Insert code here.
 }


Visual C++

[Designer("System.Windows.Forms.Design.DocumentDesigner, System.Windows.Forms.Design",
IRootDesigner::typeid),
DesignerCategory("Form")]
ref class MyForm: public ContainerControl{
   // Insert code here.
};


The next example creates an instance of MyForm. Then it gets the attributes for the class, extracts the DesignerCategoryAttribute, and prints the name of the designer.

Visual Basic

Public Shared Function Main() As Integer
    ' Creates a new form.
    Dim myNewForm As New MyForm()

    ' Gets the attributes for the collection.
    Dim attributes As AttributeCollection = TypeDescriptor.GetAttributes(myNewForm)

    ' Prints the name of the designer by retrieving the
    ' DesignerCategoryAttribute from the AttributeCollection. 
    Dim myAttribute As DesignerCategoryAttribute = _
        CType(attributes(GetType(DesignerCategoryAttribute)), DesignerCategoryAttribute)
    Console.WriteLine(("The category of the designer for this class is: " + myAttribute.Category))
    Return 0
End Function 'Main


C#

public static int Main() {
    // Creates a new form.
    MyForm myNewForm = new MyForm();

    // Gets the attributes for the collection.
    AttributeCollection attributes = TypeDescriptor.GetAttributes(myNewForm);

    /* Prints the name of the designer by retrieving the 
     * DesignerCategoryAttribute from the AttributeCollection. */
    DesignerCategoryAttribute myAttribute = 
       (DesignerCategoryAttribute)attributes[typeof(DesignerCategoryAttribute)];
    Console.WriteLine("The category of the designer for this class is: " + myAttribute.Category);

    return 0;
}


Visual C++

int main()
{
   // Creates a new form.
   MyForm^ myNewForm = gcnew MyForm;

   // Gets the attributes for the collection.
   AttributeCollection^ attributes = TypeDescriptor::GetAttributes( myNewForm );

   /* Prints the name of the designer by retrieving the 
       * DesignerCategoryAttribute from the AttributeCollection. */
   DesignerCategoryAttribute^ myAttribute = dynamic_cast<DesignerCategoryAttribute^>(attributes[ DesignerCategoryAttribute::typeid ]);
   Console::WriteLine( "The category of the designer for this class is: {0}", myAttribute->Category );
   return 0;
}


Version Information

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1
Platforms

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
See Also

Reference