此视图不允许使用WPF“EditItem”

我知道有很多关于这个错误的问题（ 1,2,3,4,5等），但我找不到解释这个错误的原因并适合我的情况。 如果我错过了一个，请告诉我！

首先，我使用自定义类（不是ObservableCollection或任何其他.NET内置的可观察集合）绑定到我的DataGrid ItemsSource 。 在向您展示其代码之前，让我解释一下我是如何想到的（我的假设可能是错误的）。

在我看来，要成为可绑定的，集合必须至少实现IEnumerable和INotifyCollectionChanged 。 IEnumerable以视图获取要显示的项目（感谢GetEnumerator方法）和INotifyCollectionChanged以便视图知道集合上的更改。

所以我最终得到了这个课程：

 public class ObservableDictionary : IDictionary, IEnumerable, INotifyCollectionChanged { #region fields private IDictionary _innerDictionary; #endregion #region properties public int Count { get { return _innerDictionary.Count; } } public ICollection Keys { get { return _innerDictionary.Keys; } } public ICollection Values { get { return _innerDictionary.Values; } } public bool IsReadOnly { get { return false; } } #endregion #region indexors public TValue this[TKey key] { get { return _innerDictionary[key]; } set { this.InternalAdd(new KeyValuePair(key, value)); } } #endregion #region events public event NotifyCollectionChangedEventHandler CollectionChanged; #endregion #region constructors public ObservableDictionary() { _innerDictionary = new Dictionary(); } public ObservableDictionary(int capacity) { _innerDictionary = new Dictionary(capacity); } public ObservableDictionary(IEqualityComparer comparer) { _innerDictionary = new Dictionary(comparer); } public ObservableDictionary(IDictionary dictionary) { _innerDictionary = new Dictionary(dictionary); } public ObservableDictionary(int capacity, IEqualityComparer comparer) { _innerDictionary = new Dictionary(capacity, comparer); } public ObservableDictionary(IDictionary dictionary, IEqualityComparer comparer) { _innerDictionary = new Dictionary(dictionary, comparer); } #endregion #region public methods public bool ContainsKey(TKey key) { return _innerDictionary.ContainsKey(key); } public bool Contains(KeyValuePair item) { return _innerDictionary.Contains(item); } public void Add(TKey key, TValue value) { this.InternalAdd(new KeyValuePair(key, value)); } public void AddRange(IEnumerable<KeyValuePair> items) { if (!items.Any()) { return; } var added = new List(); var removed = new List(); foreach (var item in items) { TValue value; if (_innerDictionary.TryGetValue(item.Key, out value)) { removed.Add(value); } added.Add(item.Value); _innerDictionary[item.Key] = item.Value; } this.CollectionChanged?.Invoke(this, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, added, null)); if (removed.Count > 0) { this.CollectionChanged?.Invoke(this, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, null, removed)); } } public void Add(KeyValuePair item) { this.InternalAdd(item); } public bool TryGetValue(TKey key, out TValue value) { return _innerDictionary.TryGetValue(key, out value); } public bool Remove(TKey key) { return this.InternalRemove(key); } public bool Remove(KeyValuePair item) { return this.InternalRemove(item.Key); } public void Clear() { _innerDictionary.Clear(); this.CollectionChanged?.Invoke(this, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Reset)); } public void CopyTo(KeyValuePair[] array, int arrayIndex) { _innerDictionary.CopyTo(array, arrayIndex); } public IEnumerator GetEnumerator() { return Values.GetEnumerator(); } IEnumerator IEnumerable.GetEnumerator() { return this.GetEnumerator(); } IEnumerator<KeyValuePair> IEnumerable<KeyValuePair>.GetEnumerator() { return _innerDictionary.GetEnumerator(); } #endregion #region private methods /// 
 /// Adds the specified value to the internal dictionary and indicates whether the element has actually been added. Fires the CollectionChanged event accordingly. /// 
 ///  ///  private void InternalAdd(KeyValuePair item) { IList added = new TValue[] { item.Value }; TValue value; if (_innerDictionary.TryGetValue(item.Key, out value)) { this.CollectionChanged?.Invoke(this, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, null, new TValue[] { value })); } _innerDictionary[item.Key] = item.Value; this.CollectionChanged?.Invoke(this, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Add, added, null)); } /// 
 /// Remove the specified key from the internal dictionary and indicates whether the element has actually been removed. Fires the CollectionChanged event accordingly. /// 
 ///  ///  private bool InternalRemove(TKey key) { TValue value; if (_innerDictionary.TryGetValue(key, out value)) { _innerDictionary.Remove(key); this.CollectionChanged?.Invoke(this, new NotifyCollectionChangedEventArgs(NotifyCollectionChangedAction.Remove, null, new TValue[] { value })); } return value != null; } #endregion } 

它隐式实现了IEnumerable.GetEnumerator并显式地实现了其他GetEnumerator方法（ IDictionary和IEnumerable ），以便我的视图只显示我的字典的值，并且我在CollectionChanged事件的调用周围映射了添加/删除方法。

我的ViewModel定义如下：

 class MyViewModel { public ObservableDictionary Foos { get; private set; } public MyViewModel() { this.Foos = new ObservableDictionary(); } } 

并将其绑定到我的视图，如下所示：

然后，当我尝试编辑Value时，我得到指定的错误：

此视图不允许使用“EditItem”

当我在代码中放入一些断点时，我从未到达ObservableDictionary索引器设置器或Foo.Value设置器。

我对关于视图如何从绑定集合中获取项目的想法进行了更正？ 为什么我收到此错误和/或如何将我的视图授权给EditItem ？