[英]C# Winforms Dictionary DataGrid Binding Auto-Refresh Without Losing Focus
In order to accomplish this, your Dictionary would need to implement IBindingList
and fire the ListChanged
event whenever changes were made. 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。 Here's a sample ( very ) barebones implementation of IDictionary<TKey, TValue>
that also implements IBindingList
: 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); }
}
Unfortunately, the selected row may or may not change, depending on which grid you're using. 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。 Your best bet is to save off the key of the selected row whenever it changes, then reselect that row (if present) when the dictionary is updated. 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)。 Otherwise, there's no way to guarantee that you'll maintain the selection. 否则,无法保证您将保持选择。
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