NotifyParentPropertyAttribute Class
Definition
Important
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Indicates that the parent property is notified when the value of the property that this attribute is applied to is modified. This class cannot be inherited.
public ref class NotifyParentPropertyAttribute sealed : Attribute
[System.AttributeUsage(System.AttributeTargets.Property)]
public sealed class NotifyParentPropertyAttribute : Attribute
public sealed class NotifyParentPropertyAttribute : Attribute
[<System.AttributeUsage(System.AttributeTargets.Property)>]
type NotifyParentPropertyAttribute = class
inherit Attribute
type NotifyParentPropertyAttribute = class
inherit Attribute
Public NotInheritable Class NotifyParentPropertyAttribute
Inherits Attribute
- Inheritance
- Attributes
Examples
The following code example demonstrates how to use the NotifyParentPropertyAttribute and the ExpandableObjectConverter class to create an expandable property on a custom control.
using System;
using System.ComponentModel;
using System.Drawing;
using System.Globalization;
using System.Windows.Forms;
namespace ExpandableObjectDemo
{
public partial class DemoControl : UserControl
{
BorderAppearance borderAppearanceValue = new BorderAppearance();
private System.ComponentModel.IContainer components = null;
public DemoControl()
{
InitializeComponent();
}
protected override void Dispose(bool disposing)
{
if (disposing && (components != null))
{
components.Dispose();
}
base.Dispose(disposing);
}
[Browsable(true)]
[EditorBrowsable(EditorBrowsableState.Always)]
[Category("Demo")]
[DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
public BorderAppearance Border
{
get
{
return this.borderAppearanceValue;
}
set
{
this.borderAppearanceValue = value;
}
}
private void InitializeComponent()
{
components = new System.ComponentModel.Container();
this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
}
}
[TypeConverter(typeof(BorderAppearanceConverter))]
public class BorderAppearance
{
private int borderSizeValue = 1;
private Color borderColorValue = Color.Empty;
[Browsable(true),
NotifyParentProperty(true),
EditorBrowsable(EditorBrowsableState.Always),
DefaultValue(1)]
public int BorderSize
{
get
{
return borderSizeValue;
}
set
{
if (value < 0)
{
throw new ArgumentOutOfRangeException(
"BorderSize",
value,
"must be >= 0");
}
if (borderSizeValue != value)
{
borderSizeValue = value;
}
}
}
[Browsable(true)]
[NotifyParentProperty(true)]
[EditorBrowsable(EditorBrowsableState.Always)]
[DefaultValue(typeof(Color), "")]
public Color BorderColor
{
get
{
return borderColorValue;
}
set
{
if (value.Equals(Color.Transparent))
{
throw new NotSupportedException("Transparent colors are not supported.");
}
if (borderColorValue != value)
{
borderColorValue = value;
}
}
}
}
public class BorderAppearanceConverter : ExpandableObjectConverter
{
// This override prevents the PropertyGrid from
// displaying the full type name in the value cell.
public override object ConvertTo(
ITypeDescriptorContext context,
CultureInfo culture,
object value,
Type destinationType)
{
if (destinationType == typeof(string))
{
return "";
}
return base.ConvertTo(
context,
culture,
value,
destinationType);
}
}
}
Imports System.ComponentModel
Imports System.Drawing
Imports System.Globalization
Imports System.Windows.Forms
Public Class DemoControl
Inherits UserControl
Private borderAppearanceValue As New BorderAppearance()
Private components As System.ComponentModel.IContainer = Nothing
Public Sub New()
InitializeComponent()
End Sub
Protected Overrides Sub Dispose(ByVal disposing As Boolean)
If disposing AndAlso (components IsNot Nothing) Then
components.Dispose()
End If
MyBase.Dispose(disposing)
End Sub
<Browsable(True), _
EditorBrowsable(EditorBrowsableState.Always), _
Category("Demo"), _
DesignerSerializationVisibility(DesignerSerializationVisibility.Content)> _
Public Property Border() As BorderAppearance
Get
Return Me.borderAppearanceValue
End Get
Set(ByVal value As BorderAppearance)
Me.borderAppearanceValue = value
End Set
End Property
Private Sub InitializeComponent()
components = New System.ComponentModel.Container()
Me.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font
End Sub
End Class
<TypeConverter(GetType(BorderAppearanceConverter))> _
Public Class BorderAppearance
Private borderSizeValue As Integer = 1
Private borderColorValue As Color = Color.Empty
<Browsable(True), NotifyParentProperty(True), EditorBrowsable(EditorBrowsableState.Always), DefaultValue(1)> _
Public Property BorderSize() As Integer
Get
Return borderSizeValue
End Get
Set
If value < 0 Then
Throw New ArgumentOutOfRangeException("BorderSize", value, "must be >= 0")
End If
If borderSizeValue <> value Then
borderSizeValue = value
End If
End Set
End Property
<Browsable(True), NotifyParentProperty(True), EditorBrowsable(EditorBrowsableState.Always), DefaultValue(GetType(Color), "")> _
Public Property BorderColor() As Color
Get
Return borderColorValue
End Get
Set
If value.Equals(Color.Transparent) Then
Throw New NotSupportedException("Transparent colors are not supported.")
End If
If borderColorValue <> value Then
borderColorValue = value
End If
End Set
End Property
End Class
Public Class BorderAppearanceConverter
Inherits ExpandableObjectConverter
' This override prevents the PropertyGrid from
' displaying the full type name in the value cell.
Public Overrides Function ConvertTo(ByVal context As ITypeDescriptorContext, ByVal culture As CultureInfo, ByVal value As Object, ByVal destinationType As Type) As Object
If destinationType Is GetType(String) Then
Return ""
End If
Return MyBase.ConvertTo(context, culture, value, destinationType)
End Function
End Class
Remarks
Apply NotifyParentPropertyAttribute to a property if its parent property should receive notification of changes to the property's values. For example, in the Properties window, the DataGridView.RowTemplate property has nested properties such as Height and DefaultCellStyle. These nested properties are marked with NotifyParentPropertyAttribute(true)
so they notify the parent property to update its value and display when the property values change.
For more information about using attributes, see Attributes.
Constructors
NotifyParentPropertyAttribute(Boolean) |
Initializes a new instance of the NotifyParentPropertyAttribute class, using the specified value to determine whether the parent property is notified of changes to the value of the property. |
Fields
Default |
Indicates the default attribute state, that the property should not notify the parent property of changes to its value. This field is read-only. |
No |
Indicates that the parent property is not be notified of changes to the value of the property. This field is read-only. |
Yes |
Indicates that the parent property is notified of changes to the value of the property. This field is read-only. |
Properties
NotifyParent |
Gets or sets a value indicating whether the parent property should be notified of changes to the value of the property. |
TypeId |
When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute) |
Methods
Equals(Object) |
Gets a value indicating whether the specified object is the same as the current object. |
GetHashCode() |
Gets the hash code for this object. |
GetType() |
Gets the Type of the current instance. (Inherited from Object) |
IsDefaultAttribute() |
Gets a value indicating whether the current value of the attribute is the default value for the attribute. |
IsDefaultAttribute() |
When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute) |
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) |
Explicit Interface Implementations
_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr) |
Maps a set of names to a corresponding set of dispatch identifiers. (Inherited from Attribute) |
_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr) |
Retrieves the type information for an object, which can be used to get the type information for an interface. (Inherited from Attribute) |
_Attribute.GetTypeInfoCount(UInt32) |
Retrieves the number of type information interfaces that an object provides (either 0 or 1). (Inherited from Attribute) |
_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr) |
Provides access to properties and methods exposed by an object. (Inherited from Attribute) |