C# · 12月 24, 2021

c# – 从一个实现INotifyPropertyChanged的基类继承?

我有这个BaseClass: public class Baseviewmodel : INotifyPropertyChanged{ protected void OnPropertyChanged(string propertyName) { if (PropertyChanged != null) { PropertyChanged(this,new PropertyChangedEventArgs(propertyName)); } } public event PropertyChangedEventHandler PropertyChanged;}

和另一个类:

public class SchemaDifferenceviewmodel : Baseviewmodel{ private string firstSchemaToCompare; public string FirstSchemaToCompare { get { return firstSchemaToCompare; } set { firstSchemaToCompare = value; if (PropertyChanged != null) { PropertyChanged(this,new PropertyChangedEventArgs(“FirstSchemaToCompare”)); //StartCommand.RaiseCanExecuteChanged(); } } }

PropertyChanged在这里(2次),红色下划线,它说:

Error 1 The event Baseviewmodel.PropertyChanged’ can only appear on the left hand side of += or -= (except when used from within the type ‘SchemaDifferenceFinder.viewmodel.Baseviewmodel’)

我做错了什么?我只将PropertyChangedEvent扫描到一个新类:Baseviewmodel ..

解决方法 您不能在声明它的类之外引发事件,使用基类中的方法来引发它(使OnPropertyChanged受保护).