我在我的基本库中创建了一个扩展方法用于重用:

public static class INotifyPropertyChangedExtensions
{
    public static bool SetPropertyAndNotify<T>(this INotifyPropertyChanged sender,
               PropertyChangedEventHandler handler, ref T field, T value, 
               [CallerMemberName] string propertyName = "",
               EqualityComparer<T> equalityComparer = null)
    {
        bool rtn = false;
        var eqComp = equalityComparer ?? EqualityComparer<T>.Default;
        if (!eqComp.Equals(field,value))
        {
            field = value;
            rtn = true;
            if (handler != null)
            {
                var args = new PropertyChangedEventArgs(propertyName);
                handler(sender, args);
            }
        }
        return rtn;
    }
}

这适用于. net 4.5，因为有CallerMemberNameAttribute。 如果你想在一个早期的。net版本中使用它，你必须改变方法声明:…，[CallerMemberName] string propertyName = ""，………，字符串propertyName…

用法:

public class Dog : INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;
    string _name;

    public string Name
    {
        get { return _name; }
        set
        {
            this.SetPropertyAndNotify(PropertyChanged, ref _name, value);
        }
    }
}

这就是大规模的过度工程。这比仅仅以正确的方式进行要复杂得多，而且几乎没有任何好处。如果你的IDE支持代码片段(Visual Studio/MonoDevelop支持)，那么你可以让这个实现变得非常简单。你需要输入的只是属性的类型和属性名。额外的三行代码将自动生成。

我真的很喜欢Marc的解决方案，但我认为可以稍微改进一下，以避免使用“魔法字符串”(不支持重构)。与其将属性名作为字符串使用，不如将其创建为lambda表达式:

private string name;
public string Name
{
    get { return name; }
    set { SetField(ref name, value, () => Name); }
}

只需要在Marc的代码中添加以下方法，就可以了:

protected virtual void OnPropertyChanged<T>(Expression<Func<T>> selectorExpression)
{
    if (selectorExpression == null)
        throw new ArgumentNullException("selectorExpression");
    MemberExpression body = selectorExpression.Body as MemberExpression;
    if (body == null)
        throw new ArgumentException("The body must be a member expression");
    OnPropertyChanged(body.Member.Name);
}

protected bool SetField<T>(ref T field, T value, Expression<Func<T>> selectorExpression)
{
    if (EqualityComparer<T>.Default.Equals(field, value)) return false;
    field = value;
    OnPropertyChanged(selectorExpression);
    return true;
}

顺便说一句，这是受到这篇博客文章的启发。

我提出了这个基类来实现可观察模式，几乎做了你所需要的(“自动”实现set和get)。我花了一个小时在这个原型上，所以它没有很多单元测试，但证明了这个概念。注意，它使用Dictionary<string, ObservablePropertyContext>来消除私有字段的需要。

  public class ObservableByTracking<T> : IObservable<T>
  {
    private readonly Dictionary<string, ObservablePropertyContext> _expando;
    private bool _isDirty;

    public ObservableByTracking()
    {
      _expando = new Dictionary<string, ObservablePropertyContext>();

      var properties = this.GetType().GetProperties(BindingFlags.Public | BindingFlags.Instance).ToList();
      foreach (var property in properties)
      {
        var valueContext = new ObservablePropertyContext(property.Name, property.PropertyType)
        {
          Value = GetDefault(property.PropertyType)
        };

        _expando[BuildKey(valueContext)] = valueContext;
      }
    }

    protected void SetValue<T>(Expression<Func<T>> expression, T value)
    {
      var keyContext = GetKeyContext(expression);
      var key = BuildKey(keyContext.PropertyName, keyContext.PropertyType);

      if (!_expando.ContainsKey(key))
      {
        throw new Exception($"Object doesn't contain {keyContext.PropertyName} property.");
      }

      var originalValue = (T)_expando[key].Value;
      if (EqualityComparer<T>.Default.Equals(originalValue, value))
      {
        return;
      }

      _expando[key].Value = value;
      _isDirty = true;
    }

    protected T GetValue<T>(Expression<Func<T>> expression)
    {
      var keyContext = GetKeyContext(expression);
      var key = BuildKey(keyContext.PropertyName, keyContext.PropertyType);

      if (!_expando.ContainsKey(key))
      {
        throw new Exception($"Object doesn't contain {keyContext.PropertyName} property.");
      }

      var value = _expando[key].Value;
      return (T)value;
    }

    private KeyContext GetKeyContext<T>(Expression<Func<T>> expression)
    {
      var castedExpression = expression.Body as MemberExpression;
      if (castedExpression == null)
      {
        throw new Exception($"Invalid expression.");
      }

      var parameterName = castedExpression.Member.Name;

      var propertyInfo = castedExpression.Member as PropertyInfo;
      if (propertyInfo == null)
      {
        throw new Exception($"Invalid expression.");
      }

      return new KeyContext {PropertyType = propertyInfo.PropertyType, PropertyName = parameterName};
    }

    private static string BuildKey(ObservablePropertyContext observablePropertyContext)
    {
      return $"{observablePropertyContext.Type.Name}.{observablePropertyContext.Name}";
    }

    private static string BuildKey(string parameterName, Type type)
    {
      return $"{type.Name}.{parameterName}";
    }

    private static object GetDefault(Type type)
    {
      if (type.IsValueType)
      {
        return Activator.CreateInstance(type);
      }
      return null;
    }

    public bool IsDirty()
    {
      return _isDirty;
    }

    public void SetPristine()
    {
      _isDirty = false;
    }

    private class KeyContext
    {
      public string PropertyName { get; set; }
      public Type PropertyType { get; set; }
    }
  }

  public interface IObservable<T>
  {
    bool IsDirty();
    void SetPristine();
  }

这是用法

public class ObservableByTrackingTestClass : ObservableByTracking<ObservableByTrackingTestClass>
  {
    public ObservableByTrackingTestClass()
    {
      StringList = new List<string>();
      StringIList = new List<string>();
      NestedCollection = new List<ObservableByTrackingTestClass>();
    }

    public IEnumerable<string> StringList
    {
      get { return GetValue(() => StringList); }
      set { SetValue(() => StringIList, value); }
    }

    public IList<string> StringIList
    {
      get { return GetValue(() => StringIList); }
      set { SetValue(() => StringIList, value); }
    }

    public int IntProperty
    {
      get { return GetValue(() => IntProperty); }
      set { SetValue(() => IntProperty, value); }
    }

    public ObservableByTrackingTestClass NestedChild
    {
      get { return GetValue(() => NestedChild); }
      set { SetValue(() => NestedChild, value); }
    }

    public IList<ObservableByTrackingTestClass> NestedCollection
    {
      get { return GetValue(() => NestedCollection); }
      set { SetValue(() => NestedCollection, value); }
    }

    public string StringProperty
    {
      get { return GetValue(() => StringProperty); }
      set { SetValue(() => StringProperty, value); }
    }
  }

我在我的博客http://timoch.com/blog/2013/08/annoyed-with-inotifypropertychange/上介绍了一个绑定类 Bindable使用字典作为属性包。为一个子类添加必要的重载以使用ref参数管理它自己的支持字段是很容易的。

没有神奇的绳子 没有反映 是否可以改进为抑制默认字典查找

代码:

public class Bindable : INotifyPropertyChanged {
    private Dictionary<string, object> _properties = new Dictionary<string, object>();

    /// <summary>
    /// Gets the value of a property
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="name"></param>
    /// <returns></returns>
    protected T Get<T>([CallerMemberName] string name = null) {
        Debug.Assert(name != null, "name != null");
        object value = null;
        if (_properties.TryGetValue(name, out value))
            return value == null ? default(T) : (T)value;
        return default(T);
    }

    /// <summary>
    /// Sets the value of a property
    /// </summary>
    /// <typeparam name="T"></typeparam>
    /// <param name="value"></param>
    /// <param name="name"></param>
    /// <remarks>Use this overload when implicitly naming the property</remarks>
    protected void Set<T>(T value, [CallerMemberName] string name = null) {
        Debug.Assert(name != null, "name != null");
        if (Equals(value, Get<T>(name)))
            return;
        _properties[name] = value;
        OnPropertyChanged(name);
    }

    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null) {
        PropertyChangedEventHandler handler = PropertyChanged;
        if (handler != null) {
            handler(this, new PropertyChangedEventArgs(propertyName));
        }
    }
}

它可以这样使用:

public class Contact : Bindable {
    public string FirstName {
        get { return Get<string>(); }
        set { Set(value); }
    }
}

还有Fody，它有一个AddINotifyPropertyChangedInterface插件，它让你这样写:

[AddINotifyPropertyChangedInterface]
public class Person 
{        
    public string GivenNames { get; set; }
    public string FamilyName { get; set; }
}

.．.并在编译时注入属性更改通知。