INotifyPropertyChanged.PropertyChanged 이벤트

정의

네임스페이스:

System.ComponentModel

어셈블리:

System.ObjectModel.dll

속성 값이 변경될 때 발생합니다.

public:
 event System::ComponentModel::PropertyChangedEventHandler ^ PropertyChanged;

event System.ComponentModel.PropertyChangedEventHandler? PropertyChanged;

member this.PropertyChanged : System.ComponentModel.PropertyChangedEventHandler 

Event PropertyChanged As PropertyChangedEventHandler 

이벤트 유형

PropertyChangedEventHandler

예제

다음 코드 예제에서는 구현 하는 방법을 보여 줍니다는 PropertyChanged 인터페이스의 INotifyPropertyChanged 이벤트입니다.

// This is a simple customer class 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 customerNameValue = string.Empty;
    private string phoneNumberValue = string.Empty;

    public event PropertyChangedEventHandler PropertyChanged;

    // This method is called by the Set accessor of each property.
    // The CallerMemberName attribute that is applied to the optional propertyName
    // parameter causes the property name of the caller to be substituted as an argument.
    private void NotifyPropertyChanged([CallerMemberName] string propertyName = "")
    {
        if (PropertyChanged != null)
        {
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
        }
    }

    // The constructor is private to enforce the factory pattern.
    private DemoCustomer()
    {
        customerNameValue = "Customer";
        phoneNumberValue = "(312)555-0100";
    }

    // 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 CustomerName
    {
        get
        {
            return this.customerNameValue;
        }

        set
        {
            if (value != this.customerNameValue)
            {
                this.customerNameValue = value;
                NotifyPropertyChanged();
            }
        }
    }

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

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

' This class implements a simple customer type 
' that implements the IPropertyChange interface.
Public Class DemoCustomer
    Implements INotifyPropertyChanged

    ' These fields hold the values for the public properties.
    Private idValue As Guid = Guid.NewGuid()
    Private customerNameValue As String = String.Empty
    Private phoneNumberValue As String = String.Empty

    Public Event PropertyChanged As PropertyChangedEventHandler _
        Implements INotifyPropertyChanged.PropertyChanged

    ' This method is called by the Set accessor of each property.
    ' The CallerMemberName attribute that is applied to the optional propertyName
    ' parameter causes the property name of the caller to be substituted as an argument.
    Private Sub NotifyPropertyChanged(<CallerMemberName()> Optional ByVal propertyName As String = Nothing)
        RaiseEvent PropertyChanged(Me, New PropertyChangedEventArgs(propertyName))
    End Sub

    ' The constructor is private to enforce the factory pattern.
    Private Sub New()
        customerNameValue = "Customer"
        phoneNumberValue = "(312)555-0100"
    End Sub

    ' This is the public factory method.
    Public Shared Function CreateNewCustomer() As DemoCustomer
        Return New DemoCustomer()
    End Function

    ' This property represents an ID, suitable
    ' for use as a primary key in a database.
    Public ReadOnly Property ID() As Guid
        Get
            Return Me.idValue
        End Get
    End Property

    Public Property CustomerName() As String
        Get
            Return Me.customerNameValue
        End Get

        Set(ByVal value As String)
            If Not (value = customerNameValue) Then
                Me.customerNameValue = value
                NotifyPropertyChanged()
            End If
        End Set
    End Property

    Public Property PhoneNumber() As String
        Get
            Return Me.phoneNumberValue
        End Get

        Set(ByVal value As String)
            If Not (value = phoneNumberValue) Then
                Me.phoneNumberValue = value
                NotifyPropertyChanged()
            End If
        End Set
    End Property
End Class

설명

이벤트는 PropertyChanged 또는 를 의 속성 이름으로 사용하여 nullString.Empty 개체의 모든 속성이 변경되었음을 나타낼 수 있습니다 PropertyChangedEventArgs. UWP 애플리케이션 String.Empty 에서는 이 아닌 null를 사용해야 합니다.

추가 정보

• PropertyChangedEventArgs