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An ObservableDictionary<TKey, TValue>
using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.ComponentModel;
using System.Diagnostics;
using System.Dynamic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Xamarin.Forms.Dynamic
{
/// <summary>
/// Provides a dictionary for use with data binding.
/// </summary>
/// <typeparam name="TKey">Specifies the type of the keys in this collection.</typeparam>
/// <typeparam name="TValue">Specifies the type of the values in this collection.</typeparam>
[DebuggerDisplay ("Count={Count}")]
public class ObservableDictionary<TKey, TValue> :
ICollection<KeyValuePair<TKey, TValue>>, IDictionary<TKey, TValue>,
INotifyCollectionChanged, INotifyPropertyChanged
{
readonly IDictionary<TKey, TValue> dictionary;
/// <summary>Event raised when the collection changes.</summary>
public event NotifyCollectionChangedEventHandler CollectionChanged = (sender, args) => { };
/// <summary>Event raised when a property on the collection changes.</summary>
public event PropertyChangedEventHandler PropertyChanged = (sender, args) => { };
/// <summary>
/// Initializes an instance of the class.
/// </summary>
public ObservableDictionary ()
: this (new Dictionary<TKey, TValue> ())
{
}
/// <summary>
/// Initializes an instance of the class using another dictionary as
/// the key/value store.
/// </summary>
public ObservableDictionary (IDictionary<TKey, TValue> dictionary)
{
this.dictionary = dictionary;
}
void AddWithNotification (KeyValuePair<TKey, TValue> item)
{
AddWithNotification (item.Key, item.Value);
}
void AddWithNotification (TKey key, TValue value)
{
dictionary.Add (key, value);
CollectionChanged (this, new NotifyCollectionChangedEventArgs (NotifyCollectionChangedAction.Add,
new KeyValuePair<TKey, TValue> (key, value)));
PropertyChanged (this, new PropertyChangedEventArgs ("Count"));
PropertyChanged (this, new PropertyChangedEventArgs ("Keys"));
PropertyChanged (this, new PropertyChangedEventArgs ("Values"));
}
bool RemoveWithNotification (TKey key)
{
TValue value;
if (dictionary.TryGetValue (key, out value) && dictionary.Remove (key)) {
CollectionChanged (this, new NotifyCollectionChangedEventArgs (NotifyCollectionChangedAction.Remove,
new KeyValuePair<TKey, TValue> (key, value)));
PropertyChanged (this, new PropertyChangedEventArgs ("Count"));
PropertyChanged (this, new PropertyChangedEventArgs ("Keys"));
PropertyChanged (this, new PropertyChangedEventArgs ("Values"));
return true;
}
return false;
}
void UpdateWithNotification (TKey key, TValue value)
{
TValue existing;
if (dictionary.TryGetValue (key, out existing)) {
dictionary[key] = value;
CollectionChanged (this, new NotifyCollectionChangedEventArgs (NotifyCollectionChangedAction.Replace,
new KeyValuePair<TKey, TValue> (key, value),
new KeyValuePair<TKey, TValue> (key, existing)));
PropertyChanged (this, new PropertyChangedEventArgs ("Values"));
} else {
AddWithNotification (key, value);
}
}
/// <summary>
/// Allows derived classes to raise custom property changed events.
/// </summary>
protected void RaisePropertyChanged(PropertyChangedEventArgs args)
{
PropertyChanged (this, args);
}
#region IDictionary<TKey,TValue> Members
/// <summary>
/// Adds an element with the provided key and value to the <see cref="T:System.Collections.Generic.IDictionary`2" />.
/// </summary>
/// <param name="key">The object to use as the key of the element to add.</param>
/// <param name="value">The object to use as the value of the element to add.</param>
public void Add (TKey key, TValue value)
{
AddWithNotification (key, value);
}
/// <summary>
/// Determines whether the <see cref="T:System.Collections.Generic.IDictionary`2" /> contains an element with the specified key.
/// </summary>
/// <param name="key">The key to locate in the <see cref="T:System.Collections.Generic.IDictionary`2" />.</param>
/// <returns>
/// true if the <see cref="T:System.Collections.Generic.IDictionary`2" /> contains an element with the key; otherwise, false.
/// </returns>
public bool ContainsKey (TKey key)
{
return dictionary.ContainsKey (key);
}
/// <summary>
/// Gets an <see cref="T:System.Collections.Generic.ICollection`1" /> containing the keys of the <see cref="T:System.Collections.Generic.IDictionary`2" />.
/// </summary>
/// <returns>An <see cref="T:System.Collections.Generic.ICollection`1" /> containing the keys of the object that implements <see cref="T:System.Collections.Generic.IDictionary`2" />.</returns>
public ICollection<TKey> Keys
{
get { return dictionary.Keys; }
}
/// <summary>
/// Removes the element with the specified key from the <see cref="T:System.Collections.Generic.IDictionary`2" />.
/// </summary>
/// <param name="key">The key of the element to remove.</param>
/// <returns>
/// true if the element is successfully removed; otherwise, false. This method also returns false if <paramref name="key" /> was not found in the original <see cref="T:System.Collections.Generic.IDictionary`2" />.
/// </returns>
public bool Remove (TKey key)
{
return RemoveWithNotification (key);
}
/// <summary>
/// Gets the value associated with the specified key.
/// </summary>
/// <param name="key">The key whose value to get.</param>
/// <param name="value">When this method returns, the value associated with the specified key, if the key is found; otherwise, the default value for the type of the <paramref name="value" /> parameter. This parameter is passed uninitialized.</param>
/// <returns>
/// true if the object that implements <see cref="T:System.Collections.Generic.IDictionary`2" /> contains an element with the specified key; otherwise, false.
/// </returns>
public bool TryGetValue (TKey key, out TValue value)
{
return dictionary.TryGetValue (key, out value);
}
/// <summary>
/// Gets an <see cref="T:System.Collections.Generic.ICollection`1" /> containing the values in the <see cref="T:System.Collections.Generic.IDictionary`2" />.
/// </summary>
/// <returns>An <see cref="T:System.Collections.Generic.ICollection`1" /> containing the values in the object that implements <see cref="T:System.Collections.Generic.IDictionary`2" />.</returns>
public ICollection<TValue> Values
{
get { return dictionary.Values; }
}
/// <summary>
/// Gets or sets the element with the specified key.
/// </summary>
/// <param name="key">The key.</param>
/// <returns></returns>
public TValue this[TKey key]
{
get { return dictionary[key]; }
set { UpdateWithNotification (key, value); }
}
#endregion
#region ICollection<KeyValuePair<TKey,TValue>> Members
void ICollection<KeyValuePair<TKey, TValue>>.Add (KeyValuePair<TKey, TValue> item)
{
AddWithNotification (item);
}
void ICollection<KeyValuePair<TKey, TValue>>.Clear ()
{
((ICollection<KeyValuePair<TKey, TValue>>)dictionary).Clear ();
CollectionChanged (this, new NotifyCollectionChangedEventArgs (NotifyCollectionChangedAction.Reset));
PropertyChanged (this, new PropertyChangedEventArgs ("Count"));
PropertyChanged (this, new PropertyChangedEventArgs ("Keys"));
PropertyChanged (this, new PropertyChangedEventArgs ("Values"));
}
bool ICollection<KeyValuePair<TKey, TValue>>.Contains (KeyValuePair<TKey, TValue> item)
{
return ((ICollection<KeyValuePair<TKey, TValue>>)dictionary).Contains (item);
}
void ICollection<KeyValuePair<TKey, TValue>>.CopyTo (KeyValuePair<TKey, TValue>[] array, int arrayIndex)
{
((ICollection<KeyValuePair<TKey, TValue>>)dictionary).CopyTo (array, arrayIndex);
}
int ICollection<KeyValuePair<TKey, TValue>>.Count
{
get { return ((ICollection<KeyValuePair<TKey, TValue>>)dictionary).Count; }
}
bool ICollection<KeyValuePair<TKey, TValue>>.IsReadOnly
{
get { return ((ICollection<KeyValuePair<TKey, TValue>>)dictionary).IsReadOnly; }
}
bool ICollection<KeyValuePair<TKey, TValue>>.Remove (KeyValuePair<TKey, TValue> item)
{
return RemoveWithNotification (item.Key);
}
#endregion
#region IEnumerable<KeyValuePair<TKey,TValue>> Members
IEnumerator<KeyValuePair<TKey, TValue>> IEnumerable<KeyValuePair<TKey, TValue>>.GetEnumerator ()
{
return ((ICollection<KeyValuePair<TKey, TValue>>)dictionary).GetEnumerator ();
}
IEnumerator IEnumerable.GetEnumerator ()
{
return ((ICollection<KeyValuePair<TKey, TValue>>)dictionary).GetEnumerator ();
}
#endregion
}
}
@woodrowbarlow

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woodrowbarlow Mar 26, 2018

i'd love to use this in a project but you haven't added any license info!

woodrowbarlow commented Mar 26, 2018

i'd love to use this in a project but you haven't added any license info!

@MSLamo

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MSLamo Jun 1, 2018

Это дерьмище не работает, нахера выладывать и писать что это прям вариант, столько времени потратил

MSLamo commented Jun 1, 2018

Это дерьмище не работает, нахера выладывать и писать что это прям вариант, столько времени потратил

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