不使用 postsharp 之类的东西，我使用的最小版本使用类似的东西：
public class Data : INotifyPropertyChanged
{
// boiler-plate
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged(string propertyName)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
}
protected bool SetField<T>(ref T field, T value, string propertyName)
{
if (EqualityComparer<T>.Default.Equals(field, value)) return false;
field = value;
OnPropertyChanged(propertyName);
return true;
}
// props
private string name;
public string Name
{
get { return name; }
set { SetField(ref name, value, "Name"); }
}
}
每个属性都类似于：
private string name;
public string Name
{
get { return name; }
set { SetField(ref name, value, "Name"); }
}
这不是很大；如果需要，它也可以用作基类。从SetField 返回的bool 告诉你它是否是空操作，以防你想应用其他逻辑。
使用 C# 5 甚至更容易：
protected bool SetField<T>(ref T field, T value,
[CallerMemberName] string propertyName = null)
{...}
可以这样调用：
set { SetField(ref name, value); }
编译器将自动添加"Name"。
C# 6.0 使实现更容易：
protected void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
...现在使用 C#7：
protected void OnPropertyChanged(string propertyName)
=> PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
protected bool SetField<T>(ref T field, T value,[CallerMemberName] string propertyName = null)
{
if (EqualityComparer<T>.Default.Equals(field, value)) return false;
field = value;
OnPropertyChanged(propertyName);
return true;
}
private string name;
public string Name
{
get => name;
set => SetField(ref name, value);
}
而且，对于 C# 8 和 Nullable 引用类型，它看起来像这样：
public event PropertyChangedEventHandler? PropertyChanged;
protected void OnPropertyChanged(string propertyName) => PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
protected bool SetField<T>(ref T field, T value, [CallerMemberName] string propertyName = "")
{
if (EqualityComparer<T>.Default.Equals(field, value)) return false;
field = value;
OnPropertyChanged(propertyName);
return true;
}
private string name;
public string Name
{
get => name;
set => SetField(ref name, value);
}