[英]WPF DataGrid auto-refresh with ObservableCollection source
[英]C# Winforms Dictionary DataGrid Binding Auto-Refresh Without Losing Focus
为了完成此操作,您的Dictionary将需要实现IBindingList
并ListChanged
更改时触发ListChanged
事件。 这是IDictionary<TKey, TValue>
的示例( 非常 )准系统实现,它也实现了IBindingList
:
public class BindableDictionary<TKey, TValue> : IDictionary<TKey, TValue>, IBindingList
{
private Dictionary<TKey, TValue> source = new Dictionary<TKey, TValue>();
void IBindingList.AddIndex(PropertyDescriptor property) { }
object IBindingList.AddNew() { throw new NotImplementedException(); }
bool IBindingList.AllowEdit { get { return false; } }
bool IBindingList.AllowNew { get { return false; } }
bool IBindingList.AllowRemove { get { return false; } }
void IBindingList.ApplySort(PropertyDescriptor property, ListSortDirection direction) { }
int IBindingList.Find(PropertyDescriptor property, object key) { throw new NotImplementedException(); }
bool IBindingList.IsSorted { get { return false; } }
void IBindingList.RemoveIndex(PropertyDescriptor property) { }
void IBindingList.RemoveSort() { }
ListSortDirection IBindingList.SortDirection { get { return ListSortDirection.Ascending; } }
PropertyDescriptor IBindingList.SortProperty { get { return null; } }
bool IBindingList.SupportsChangeNotification { get { return true; } }
bool IBindingList.SupportsSearching { get { return false; } }
bool IBindingList.SupportsSorting { get { return false; } }
int System.Collections.IList.Add(object value) { throw new NotImplementedException(); }
void System.Collections.IList.Clear() { Clear(); }
bool System.Collections.IList.Contains(object value) { if (value is TKey) { return source.ContainsKey((TKey)value); } else if (value is TValue) { return source.ContainsValue((TValue)value); } return false; }
int System.Collections.IList.IndexOf(object value) { return -1; }
void System.Collections.IList.Insert(int index, object value) { throw new NotImplementedException(); }
bool System.Collections.IList.IsFixedSize { get { return false; } }
bool System.Collections.IList.IsReadOnly { get { return true; } }
void System.Collections.IList.Remove(object value) { if (value is TKey) { Remove((TKey)value); } }
void System.Collections.IList.RemoveAt(int index) { throw new NotImplementedException(); }
object System.Collections.IList.this[int index] { get { throw new NotImplementedException(); } set { throw new NotImplementedException(); } }
private ListChangedEventHandler listChanged;
event ListChangedEventHandler IBindingList.ListChanged
{
add { listChanged += value; }
remove { listChanged -= value; }
}
protected virtual void OnListChanged(ListChangedEventArgs e)
{
var evt = listChanged;
if (evt != null) evt(this, e);
}
public void Add(TKey key, TValue value)
{
source.Add(key, value);
OnListChanged(new ListChangedEventArgs(ListChangedType.Reset, -1));
}
public bool Remove(TKey key)
{
if (source.Remove(key))
{
OnListChanged(new ListChangedEventArgs(ListChangedType.Reset, -1));
return true;
}
return false;
}
public TValue this[TKey key]
{
get
{
return source[key];
}
set
{
source[key] = value;
OnListChanged(new ListChangedEventArgs(ListChangedType.Reset, -1));
}
}
void ICollection<KeyValuePair<TKey, TValue>>.Add(KeyValuePair<TKey, TValue> item)
{
((ICollection<KeyValuePair<TKey, TValue>>)source).Add(item);
OnListChanged(new ListChangedEventArgs(ListChangedType.Reset, -1));
}
bool ICollection<KeyValuePair<TKey, TValue>>.Remove(KeyValuePair<TKey, TValue> item)
{
if (((ICollection<KeyValuePair<TKey, TValue>>)source).Remove(item))
{
OnListChanged(new ListChangedEventArgs(ListChangedType.Reset, -1));
return true;
}
return false;
}
public bool ContainsKey(TKey key) { return source.ContainsKey(key); }
public ICollection<TKey> Keys { get { return source.Keys; } }
public bool TryGetValue(TKey key, out TValue value) { return source.TryGetValue(key, out value); }
public ICollection<TValue> Values { get { return source.Values; } }
public void Clear() { source.Clear(); }
bool ICollection<KeyValuePair<TKey, TValue>>.Contains(KeyValuePair<TKey, TValue> item) { return ((ICollection<KeyValuePair<TKey, TValue>>)source).Contains(item); }
void ICollection<KeyValuePair<TKey, TValue>>.CopyTo(KeyValuePair<TKey, TValue>[] array, int arrayIndex) { ((ICollection<KeyValuePair<TKey, TValue>>)source).CopyTo(array, arrayIndex); }
public int Count { get { return source.Count; } }
bool ICollection<KeyValuePair<TKey, TValue>>.IsReadOnly { get { return ((ICollection<KeyValuePair<TKey, TValue>>)source).IsReadOnly; } }
public IEnumerator<KeyValuePair<TKey, TValue>> GetEnumerator() { return source.GetEnumerator(); }
System.Collections.IEnumerator System.Collections.IEnumerable.GetEnumerator() { return GetEnumerator(); }
bool ICollection.IsSynchronized { get { return false; } }
object ICollection.SyncRoot { get { return null; } }
void ICollection.CopyTo(Array array, int arrayIndex) { ((ICollection)source).CopyTo(array,arrayIndex); }
}
不幸的是,所选行可能会更改,也可能不会更改,具体取决于您所使用的网格。 最好的选择是,只要更改了所选行的键,便会保留该键,然后在更新字典时重新选择该行(如果存在)。 否则,无法保证您将保持选择。
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