Simplest way to achieve automatic notification of property change

Question

I know that there are solutions out there for implementing INotifyPropertyChanged, but none of them are as simple as: reference this library, create/add this attribute, done (I'm thinking Aspect-Oriented Programming here). Does anyone know of a really simple way to do this? Bonus points if the solution is free.

Here are some relevant links (none of which provide a simple enough answer):

• Aspect Examples (INotifyPropertyChanged via aspects)
• LinFu
• INotifyPropertyChanged auto wiring or how to get rid of redundant code
• INotifyPropertyChanged With Unity Interception AOP

Answer 1

Try this https://github.com/Fody/PropertyChanged

It will weave all properties of types that implement INotifyPropertyChanged and even handles dependencies.

Your Code

public class Person : INotifyPropertyChanged {     public event PropertyChangedEventHandler PropertyChanged;      public string GivenNames { get; set; }     public string FamilyName { get; set; }      public string FullName     {         get         {             return string.Format("{0} {1}", GivenNames, FamilyName);         }     }  } 

What gets compiled

public class Person : INotifyPropertyChanged {      public event PropertyChangedEventHandler PropertyChanged;      private string givenNames;     public string GivenNames     {         get { return givenNames; }         set         {             if (value != givenNames)             {                 givenNames = value;                 OnPropertyChanged("GivenNames");                 OnPropertyChanged("FullName");             }         }     }      private string familyName;     public string FamilyName     {         get { return familyName; }         set          {             if (value != familyName)             {                 familyName = value;                 OnPropertyChanged("FamilyName");                 OnPropertyChanged("FullName");             }         }     }      public string FullName     {         get         {             return string.Format("{0} {1}", GivenNames, FamilyName);         }     }          public void OnPropertyChanged(string propertyName)     {         var propertyChanged = PropertyChanged;         if (propertyChanged != null)         {             propertyChanged(this, new PropertyChangedEventArgs(propertyName));             }     } } 

Or you can use attributes for more fine grained control.

Answer 2

Here is an article showing how to handle this via PostSharp.