NotifyParentPropertyAttribute Class

Definition

Namespace:

System.ComponentModel

Assemblies:

netstandard.dll, System.ComponentModel.Primitives.dll

Source:

NotifyParentPropertyAttribute.cs

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.

C#

[System.AttributeUsage(System.AttributeTargets.Property)]
public sealed class NotifyParentPropertyAttribute : Attribute

Inheritance

Object

Attribute

NotifyParentPropertyAttribute

Attributes

AttributeUsageAttribute

Examples

The following code example demonstrates how to use the NotifyParentPropertyAttribute and the ExpandableObjectConverter class to create an expandable property on a custom control.

C#

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);
        }
    }
}

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.
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)

Applies to

See also

• ExpandableObjectConverter
• Attribute