我看到两种类型的实现INotifyPropertyChanged
第一个：
public abstract class ViewModelBase : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
}
第二个：
public abstract class ViewModelBase : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
[NotifyPropertyChangedInvocator]
protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null)
{
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
}
在第二个中你会看到有一个额外的属性[NotifyPropertyChangedInvocator]关于方法OnPropertyChanged
就我而言，两者的行为相同，但是什么、为什么以及何时使用它[NotifyPropertyChangedInvocator]，这样做有什么好处？我在互联网上搜索过但找不到任何好的答案。
这是他们的 Resharper 属性注释 https://www.jetbrains.com/help/resharper/Code_Analysis__Code_Annotations.html- 旨在向您发出警告，然后您的代码看起来很可疑:)
考虑一下：
public class Foo : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
[NotifyPropertyChangedInvocator]
protected virtual void NotifyChanged(string propertyName) { ... }
private string _name;
public string Name {
get { return _name; }
set {
_name = value;
NotifyChanged("LastName");//<-- warning here
}
}
}
With the [NotifyPropertyChangedInvocator] attribute on the NotifyChanged method Resharper will give you a warning, that you are invoking the method with a (presumably) wrong value.
Because Resharper now knows that method should be called to make change notification, it will help you convert normal properties into properties with change notification:
Converting it into this:
public string Name
{
get { return _name; }
set
{
if (value == _name) return;
_name = value;
NotifyChange("Name");
}
}
This example is from the documentation on the [NotifyPropertyChangedInvocator] attribute found here:
