c# - BindableBase 与 INotifyChanged

Question

有谁知道 BindableBase 是否仍然可行，或者我们应该坚持使用 INotifyChanged 事件？看起来 BindableBase 很快就失去了光彩。感谢您提供的任何信息。

Answer 1

INotifyPropertyChanged

ViewModel 应该实现 INotifyPropertyChanged 接口(interface)并且应该在属性改变时引发它

public class MyViewModel : INotifyPropertyChanged
{
    private string _firstName;


    public event PropertyChangedEventHandler PropertyChanged;

    public string FirstName
    {
        get { return _firstName; }
        set
        {
            if (_firstName == value)
                return;

            _firstName = value;
            PropertyChanged(this, new PropertyChangedEventArgs("FirstName"));
        }
    }


    }
}

问题出在 ICommand 接口(interface)上，因为大部分代码都是重复的，而且由于它传递字符串，因此很容易出错。

而Bindablebase 是一个抽象类，它实现了INotifyPropertyChanged 接口(interface)并提供了SetProperty<T>。 .您可以将 set 方法减少到只有一行，ref 参数也允许您更新它的值。下面的 BindableBase 代码来自 INotifyPropertyChanged, The .NET 4.5 Way - Revisited

   public class MyViewModel : BindableBase
{
    private string _firstName;
    private string _lastName;

    public string FirstName
    {
        get { return _firstName; }
        set { SetProperty(ref _firstName, value); }
    }


}

     //Inside Bindable Base
    public abstract class BindableBase : INotifyPropertyChanged
    {

       public event PropertyChangedEventHandler PropertyChanged;

       protected bool SetProperty<T>(ref T storage, T value, [CallerMemberName] String propertyName = null)
       {
          if (Equals(storage, value))
          {
             return false;
          }

          storage = value;
          this.OnPropertyChanged(propertyName);
          return true;
       }

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