BindableAttribute Class

Definition

Namespace:

System.ComponentModel

Assembly:

System.ComponentModel.TypeConverter.dll

Source:

BindableAttribute.cs

Specifies whether a member is typically used for binding. This class cannot be inherited.

public ref class BindableAttribute sealed : Attribute

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

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

Public NotInheritable Class BindableAttribute
Inherits Attribute

Inheritance

Object

Attribute

BindableAttribute

Attributes

AttributeUsageAttribute

Examples

The following code example marks a property as appropriate to bind data to.

property int MyProperty 
{
   [System::ComponentModel::Bindable(true)]
   int get()
   {
      // Insert code here.
      return 0;
   }

   [System::ComponentModel::Bindable(true)]
   void set( int )
   {
      // Insert code here.
   }
}

[Bindable(true)]
 public int MyProperty {
    get {
       // Insert code here.
       return 0;
    }
    set {
       // Insert code here.
    }
 }

<Bindable(True)> _
Public Property MyProperty() As Integer
    Get
        ' Insert code here.
        Return 0
    End Get
    Set
         ' Insert code here.
    End Set
End Property

The next code example shows how to check the value of the BindableAttribute for MyProperty. First, the code gets a PropertyDescriptorCollection with all the properties for the object. Next, the code indexes into the PropertyDescriptorCollection to get MyProperty. Finally, the code returns the attributes for this property and saves them in the attributes variable. The code example presents two different ways to check the value of the BindableAttribute. In the second code fragment, the example calls the Equals method. In the last code fragment, the example uses the Bindable property to check the value.

using namespace System::ComponentModel;

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

// Checks to see if the value of the BindableAttribute is Yes.
if ( attributes[ BindableAttribute::typeid ]->Equals( BindableAttribute::Yes ) )
{
   // Insert code here.
}

// This is another way to see whether the property is bindable.
BindableAttribute^ myAttribute = static_cast<BindableAttribute^>(attributes[ BindableAttribute::typeid ]);
if ( myAttribute->Bindable )
{
   // Insert code here.
}

// Yet another way to see whether the property is bindable.
if ( attributes->Contains( BindableAttribute::Yes ) )
{
   // Insert code here.
}

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

    // Checks to see if the value of the BindableAttribute is Yes.
    if(attributes[typeof(BindableAttribute)].Equals(BindableAttribute.Yes)) {
       // Insert code here.
    }

    // This is another way to see whether the property is bindable.
    BindableAttribute myAttribute =
       (BindableAttribute)attributes[typeof(BindableAttribute)];
    if(myAttribute.Bindable) {
       // Insert code here.
    }

// Yet another way to see whether the property is bindable.
if (attributes.Contains(BindableAttribute.Yes)) {
   // Insert code here.
}

    ' Gets the attributes for the property.
    Dim attributes As AttributeCollection = _
        TypeDescriptor.GetProperties(Me)("MyProperty").Attributes
    
    ' Checks to see if the value of the BindableAttribute is Yes.
    If attributes(GetType(BindableAttribute)).Equals(BindableAttribute.Yes) Then
        ' Insert code here.
    End If 
    
    ' This is another way to see whether the property is bindable.
    Dim myAttribute As BindableAttribute = _
        CType(attributes(GetType(BindableAttribute)), BindableAttribute)
    If myAttribute.Bindable Then
        ' Insert code here.
    End If 

' Yet another way to see whether the property is bindable.
If attributes.Contains(BindableAttribute.Yes) Then
' Insert code here.
End If

If you marked a class with the BindableAttribute, use the following code example to check the value.

using namespace System::ComponentModel;
AttributeCollection^ attributes = TypeDescriptor::GetAttributes( MyProperty );
if ( attributes[ BindableAttribute::typeid ]->Equals( BindableAttribute::Yes ) )
{
   // Insert code here.
}

AttributeCollection attributes =
    TypeDescriptor.GetAttributes(MyProperty);
 if(attributes[typeof(BindableAttribute)].Equals(BindableAttribute.Yes)) {
    // Insert code here.
 }

Dim attributes As AttributeCollection = TypeDescriptor.GetAttributes(MyProperty)
If attributes(GetType(BindableAttribute)).Equals(BindableAttribute.Yes) Then
    ' Insert code here.
End If

Remarks

You can specify this attribute for multiple members, typically properties, on a control.

If a property has been marked with the BindableAttribute set to true, then a property change notification should be raised for that property. This means that if the Bindable property is Yes, then two-way data binding is supported. If Bindable is No, you can still bind to the property, but it should not be shown in the default set of properties to bind to, because it might or might not raise a property change notification.

Note

When you mark a property with BindableAttribute set to true, the value of this attribute is set to the constant member Yes. For a property marked with the BindableAttribute set to false, the value is No. Therefore, to check the value of this attribute in your code, you must specify the attribute as BindableAttribute.Yes or BindableAttribute.No.

Caution

You can use this attribute at design time only. Nothing prevents you from binding to any property during run time.

For more information, see Attributes.

Constructors

BindableAttribute(BindableSupport, BindingDirection)	Initializes a new instance of the BindableAttribute class.
BindableAttribute(BindableSupport)	Initializes a new instance of the BindableAttribute class with one of the BindableSupport values.
BindableAttribute(Boolean, BindingDirection)	Initializes a new instance of the BindableAttribute class.
BindableAttribute(Boolean)	Initializes a new instance of the BindableAttribute class with a Boolean value.

Fields

Default	Specifies the default value for the BindableAttribute, which is No. This field is read-only.
No	Specifies that a property is not typically used for binding. This field is read-only.
Yes	Specifies that a property is typically used for binding. This field is read-only.

Properties

Bindable	Gets a value indicating that a property is typically used for binding.
Direction	Gets a value indicating the direction or directions of this property's data binding.
TypeId	When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute)

Methods

Equals(Object)	Determines whether two BindableAttribute objects are equal.
GetHashCode()	Serves as a hash function for the BindableAttribute class.
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
• AttributeCollection
• PropertyDescriptorCollection