## On this page

  

 

 # Class ObservableKeyedCollectionBase<TKey, TItem\\>

 Last update: 09.03.2026 

<a id="VM_Collections_ObservableKeyedCollectionBase_2"></a>

Namespace: [VM.Collections](VM.Collections.md)  
Assembly: VM.dll

```csharp
public abstract class ObservableKeyedCollectionBase<TKey, TItem> : KeyedCollection<TKey, TItem>

```

#### Type Parameters

`TKey`

`TItem`

#### Inheritance

object ← Collection&lt;TItem&gt; ← KeyedCollection&lt;TKey, TItem&gt; ← [ObservableKeyedCollectionBase&lt;TKey, TItem&gt;](VM.Collections.ObservableKeyedCollectionBase-2.md)

## Constructors

### <a id="VM_Collections_ObservableKeyedCollectionBase_2__ctor"></a> ObservableKeyedCollectionBase()

```csharp
protected ObservableKeyedCollectionBase()

```

## Methods

### <a id="VM_Collections_ObservableKeyedCollectionBase_2___OnPropertyChanged_System_ComponentModel_PropertyChangedEventArgs_"></a> &lt;&gt;OnPropertyChanged(PropertyChangedEventArgs)

```csharp
protected void <>OnPropertyChanged(PropertyChangedEventArgs eventArgs)

```

#### Parameters

`eventArgs` PropertyChangedEventArgs

### <a id="VM_Collections_ObservableKeyedCollectionBase_2_AddRange_System_Collections_Generic_IEnumerable__1__"></a> AddRange(IEnumerable&lt;TItem&gt;)

```csharp
public void AddRange(IEnumerable<TItem> items)

```

#### Parameters

`items` IEnumerable&lt;TItem&gt;

### <a id="VM_Collections_ObservableKeyedCollectionBase_2_ClearItems"></a> ClearItems()

```csharp
protected override void ClearItems()

```

### <a id="VM_Collections_ObservableKeyedCollectionBase_2_InsertItem_System_Int32__1_"></a> InsertItem(int, TItem)

```csharp
protected override void InsertItem(int index, TItem item)

```

#### Parameters

`index` int

`item` TItem

### <a id="VM_Collections_ObservableKeyedCollectionBase_2_OnCollectionChanged_System_Collections_Specialized_NotifyCollectionChangedEventArgs_"></a> OnCollectionChanged(NotifyCollectionChangedEventArgs)

```csharp
protected virtual void OnCollectionChanged(NotifyCollectionChangedEventArgs e)

```

#### Parameters

`e` NotifyCollectionChangedEventArgs

### <a id="VM_Collections_ObservableKeyedCollectionBase_2_RemoveItem_System_Int32_"></a> RemoveItem(int)

```csharp
protected override void RemoveItem(int index)

```

#### Parameters

`index` int

### <a id="VM_Collections_ObservableKeyedCollectionBase_2_SetItem_System_Int32__1_"></a> SetItem(int, TItem)

```csharp
protected override void SetItem(int index, TItem newitem)

```

#### Parameters

`index` int

`newitem` TItem

### <a id="VM_Collections_ObservableKeyedCollectionBase_2_TryGetValue__0__1__"></a> TryGetValue(TKey, out TItem)

```csharp
public bool TryGetValue(TKey key, out TItem item)

```

#### Parameters

`key` TKey

`item` TItem

#### Returns

bool

### <a id="VM_Collections_ObservableKeyedCollectionBase_2_CollectionChanged"></a> CollectionChanged

```csharp
public event NotifyCollectionChangedEventHandler CollectionChanged

```

#### Event Type

NotifyCollectionChangedEventHandler

### <a id="VM_Collections_ObservableKeyedCollectionBase_2_PropertyChanged"></a> PropertyChanged

```csharp
public event PropertyChangedEventHandler PropertyChanged

```

#### Event Type

PropertyChangedEventHandler