ComponentChangedEventArgs Class

 
System_CAPS_noteNote

The .NET API Reference documentation has a new home. Visit the .NET API Browser on docs.microsoft.com to see the new experience.

Provides data for the ComponentChanged event. This class cannot be inherited.

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

System.Object
  System.EventArgs
    System.ComponentModel.Design.ComponentChangedEventArgs

[ComVisibleAttribute(true)]
[HostProtectionAttribute(SecurityAction.LinkDemand, SharedState = true)]
[PermissionSetAttribute(SecurityAction.LinkDemand, Name = "FullTrust")]
public sealed class ComponentChangedEventArgs : EventArgs

NameDescription
System_CAPS_pubmethodComponentChangedEventArgs(Object, MemberDescriptor, Object, Object)

Initializes a new instance of the ComponentChangedEventArgs class.

NameDescription
System_CAPS_pubpropertyComponent

Gets the component that was modified.

System_CAPS_pubpropertyMember

Gets the member that has been changed.

System_CAPS_pubpropertyNewValue

Gets the new value of the changed member.

System_CAPS_pubpropertyOldValue

Gets the old value of the changed member.

NameDescription
System_CAPS_pubmethodEquals(Object)

Determines whether the specified object is equal to the current object.(Inherited from Object.)

System_CAPS_pubmethodGetHashCode()

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethodToString()

Returns a string that represents the current object.(Inherited from Object.)

ComponentChangedEventArgs provides data for a ComponentChanged event. The ComponentChanged event notifies the IComponentChangeService and registered event handlers that a particular component in the currently active document has been changed.

A ComponentChangedEventArgs provides the following information:

  • A Component property that indicates the component that was modified.

  • A Member property that indicates the member that was changed.

  • A NewValue property that indicates the new value of the member.

  • An OldValue property that indicates the old value of the member.

Component designers typically raise the ComponentChanged event automatically when components are added, removed, or modified. A ComponentChanged event is not raised during form load and unload because changes at this time are expected. A component designer might raise the ComponentChanged event after it changes a property of the component; this ensures that the Properties window will display the updated property.

Notes to Inheritors:

A compiler error occurs if this class is specified as the base class of another class.

The following example demonstrates creating a ComponentChangedEventArgs.

// This example method creates a ComponentChangedEventArgs using the specified arguments.
// Typically, this type of event args is created by a design mode subsystem.            
public ComponentChangedEventArgs CreateComponentChangedEventArgs(object component, MemberDescriptor member, object oldValue, object newValue)
{            
    // Creates a component changed event args with the specified arguments.
    ComponentChangedEventArgs args = new ComponentChangedEventArgs(component, member, oldValue, newValue);

    // The component that has changed:              args.Component
    // The member of the component that changed:    args.Member
    // The old value of the member:                 args.oldValue
    // The new value of the member:                 args.newValue

    return args;            
}

.NET Framework
Available since 1.1

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

Return to top
Show: