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INotifyPropertyChanged.PropertyChanged Event

Occurs when a property value changes.

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

event PropertyChangedEventHandler PropertyChanged
/** @event */
void add_PropertyChanged (PropertyChangedEventHandler value)

/** @event */
void remove_PropertyChanged (PropertyChangedEventHandler value)

In JScript, you can handle the events defined by a class, but you cannot define your own.
Not applicable.

The PropertyChanged event can indicate all properties on the object have changed by using either a null reference (Nothing in Visual Basic) or String.Empty as the property name in the PropertyChangedEventArgs.

The following code example demonstrates how to implement the PropertyChanged event of the INotifyPropertyChanged interface.

// This class implements a simple customer type 
// that implements the IPropertyChange interface.
public class DemoCustomer : INotifyPropertyChanged
{
	// These fields hold the values for the public properties.
	private Guid idValue = Guid.NewGuid();
	private string customerName = String.Empty;
	private string companyNameValue = String.Empty;
	private string phoneNumberValue = String.Empty;

	public event PropertyChangedEventHandler PropertyChanged;
	
	private void NotifyPropertyChanged(String info)
	{
		if (PropertyChanged != null)
		{
			PropertyChanged(this, new PropertyChangedEventArgs(info));
		}
	}

	// The constructor is private to enforce the factory pattern.
	private DemoCustomer()
	{
		customerName = "no data";
		companyNameValue = "no data";
		phoneNumberValue = "no data";
	}

	// This is the public factory method.
	public static DemoCustomer CreateNewCustomer()
	{
		return new DemoCustomer();
	}

	// This property represents an ID, suitable
	// for use as a primary key in a database.
	public Guid ID
	{
		get
		{
			return this.idValue;
		}
	}

	public string CompanyName
	{
		get
		{
			return this.companyNameValue;
		}

		set
		{
            if (value != this.companyNameValue)
            {
                this.companyNameValue = value;
                NotifyPropertyChanged("CompanyName");
            }
		}
	}

	public string PhoneNumber
	{
		get
		{
			return this.phoneNumberValue;
		}

		set
		{
            if (value != this.phoneNumberValue)
            {
                this.phoneNumberValue = value;
                NotifyPropertyChanged("PhoneNumber");
            }
		}
	}
}

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0

.NET Compact Framework

Supported in: 2.0

XNA Framework

Supported in: 1.0

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