Notify (keyword)

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Property Notification

When notify is used on properties, the class will implicitly implement the System.ComponentModel.INotifyPropertyChanged and System.ComponentModel.INotifyPropertyChanging interface (if available, when linking against .NET 3.5, otherwise it will not be exposed) and invoke the event defined in that interface when the property itself is modified.

By default, it will pass the name of the property as defined in the class, however, notify supports a string parameter to change the name of the property passed to the event.

Defining

type
  ValueClass = class
  public
    property Value: Integer; notify;
    property Name: string; notify 'ValueName';
  end;

Using

var
  v: ValueClass;

v.PropertyChanged += 
  method (sender: Object; args: PropertyChangedEventArgs) 
  begin
    MessageBox.Show(String.Format('Someone changed the {0} property', args.PropertyName));
  end;

Compatibility Remarks

• If you have .NET 2.0 SP1 on your machine, Delphi Prism will use INotifyPropertyChanging as well
  This can cause problems on target machines that do not have SP1 for .Net 2.0 installed.
  In those cases, having a VM with just .NET 2.0 and the Delphi Prism compiler would be a workaround to ensure that your app does not need SP1.

See Also

• Properties

Area: Oxygene Language
Compiler version: Oxygene 5

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