WPFのPropertyChangedコードエラー：実装できません「

Question

私はこのコードを持っているSystem.ComponentModel.INotifyPropertyChanged：

using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Text; 
using System.Data; 
using System.ComponentModel; 
using System.Collections.Specialized; 
using System.Collections.ObjectModel; 

namespace Bix 
{ 
    public class SettingsDataObject 
    { 
     private int id; 
     public int Id 
     { 
      get { return id; } 
      set { id = value == 0 ? Db.GetNextSettingsId() : value; } 
     } 
     private string adminEmail; public string AdminEmail { 
      get { return adminEmail; } 
      set { adminEmail = value; } 
     } 
     private int state; public int State { get { return state; } set { state = value == 0 ? 1 : value; } } 

     public object[] GetArray() 
     { 
      return new object[] { id, adminEmail, state }; 
     } 

     public SettingsDataObject() 
     { 

     } 
    } 

    public class SettingsUIObjects : ObservableCollection<SettingsUIObject>,INotifyPropertyChanged 
    { 
     protected override void InsertItem(int index, SettingsUIObject item) 
     { 
      base.InsertItem(index, item); 

      // handle any EndEdit events relating to this item 
      item.ItemEndEdit += new SettingsUIObject.ItemEndEditEventHandler(ItemEndEditHandler); 
      item.PropertyChanged += new SettingsUIObject.PropertyChangedEventHandler(PropertyChanged); 
     } 

     public void ItemEndEditHandler(IEditableObject sender) 
     { 
      // simply forward any EndEdit events 
      if (ItemEndEdit != null) 
      { 
       ItemEndEdit(sender); 
      } 
     } 

     public event SettingsUIObject.ItemEndEditEventHandler ItemEndEdit; 
     public event SettingsUIObject.PropertyChangedEventHandler PropertyChanged; 
    } 

    public class SettingsDataProvider 
    { 
     private DataAccessLayer dl; 

     public SettingsDataProvider() 
     { 
      dl = new DataAccessLayer(); 
     } 

     public SettingsUIObjects GetSettings() 
     { 
      try 
      { 
       SettingsUIObjects objs = new SettingsUIObjects(); 

       List<SettingsDataObject> objDataObjects = dl.GetSettings(); 
       foreach (SettingsDataObject obj in objDataObjects) 
       { 
        objs.Add(new SettingsUIObject(obj)); 
       } 

       objs.ItemEndEdit += new SettingsUIObject.ItemEndEditEventHandler(SettingsItemEndEdit); 
       objs.CollectionChanged += new 
        NotifyCollectionChangedEventHandler(SettingsCollectionChanged); 
       objs.PropertyChanged += new SettingsUIObject.PropertyChangedEventHandler(SettingsPropertyChanged); 
       return objs; 
      } 
      catch (Exception) { return new SettingsUIObjects(); } 
     } 

     void SettingsItemEndEdit(IEditableObject sender) 
     { 
      SettingsUIObject obj = sender as SettingsUIObject; 

      // use the data access layer to update the wrapped data object 
      dl.UpdateSettings(obj.GetDataObject()); 
     } 

     void SettingsPropertyChanged(INotifyPropertyChanged sender, PropertyChangedEventArgs e) 
     { 
      SettingsUIObject obj = sender as SettingsUIObject; 

      // use the data access layer to update the wrapped data object 
      dl.UpdateSettings(obj.GetDataObject()); 
     } 

     void SettingsCollectionChanged(object sender, NotifyCollectionChangedEventArgs e) 
     { 
      if (e.Action == NotifyCollectionChangedAction.Remove) 
      { 
       foreach (object item in e.OldItems) 
       { 
        SettingsUIObject obj = item as SettingsUIObject; 

        // use the data access layer to delete the wrapped data object 
        dl.DeleteSettings(obj.GetDataObject()); 
       } 
      } 
      if (e.Action == NotifyCollectionChangedAction.Add) 
      { 
       foreach (object item in e.NewItems) 
       { 
        SettingsUIObject obj = item as SettingsUIObject; 

        // use the data access layer to delete the wrapped data object 
        dl.UpdateSettings(obj.GetDataObject()); 
       } 
      } 
     } 
    } 

    public class SettingsUIObject : IEditableObject, INotifyPropertyChanged 
    { 
     private SettingsDataObject obj; 
     public SettingsUIObject(SettingsDataObject o) 
     { 
      obj = o; 
     } 

     public SettingsDataObject GetDataObject() 
     { 
      return obj; 
     } 

     public int Id { get { return obj.Id; } set { obj.Id = value; } } 
     public string AdminEmail { 
      get { return obj.AdminEmail; } 
      set { obj.AdminEmail = value; } 
     } 

     public delegate void ItemEndEditEventHandler(IEditableObject sender); 

     public event ItemEndEditEventHandler ItemEndEdit; 

     #region IEditableObject Members 

     public void BeginEdit() { } 

     public void CancelEdit() { } 

     public void EndEdit() 
     { 
      if (ItemEndEdit != null) 
      { 
       ItemEndEdit(this); 
      } 
     } 

     #endregion 

     public delegate void PropertyChangedEventHandler(INotifyPropertyChanged sender, PropertyChangedEventArgs e); 
     public event PropertyChangedEventHandler PropertyChanged; 

     private void NotifyPropertyChanged(string info) 
     { 
      if (PropertyChanged != null) 
      { 
       PropertyChanged(this, new PropertyChangedEventArgs(info)); 
      } 
     } 

    } 
} 

を、私はコンパイルエラーになっ保つ：

『Bix.SettingsUIObject』インターフェイスメンバを実装していないがプロパティ。 'System.ComponentModel.PropertyChangedEventHandler'の一致する戻り値の型がないため、 'Bix.SettingsUIObject.PropertyChanged'は実装できません。

誰でも私にその理由を教えてもらえますか？

おかげ

オーソン

Answer 1

public delegate void PropertyChangedEventHandler(INotifyPropertyChanged sender, PropertyChangedEventArgs e); 
    public event PropertyChangedEventHandler PropertyChanged; 

あなたのコードはSystem.ComponentModelで宣言されたものを隠すPropertyChangedEventHandlerデリゲートを、再宣言します。イベントのタイプはSettingsUIObject.PropertyChangedEventHandlerで、System.ComponentModel.PropertyChangedEventHandlerではありません。型がINotifyPropertyChangedで宣言された型と一致しないため、PropertyChangedイベントはインタフェースの有効な実装ではありません。

PropertyChangedEventHandlerデリゲートを削除するだけで正常に動作します。