ObservableCollection<(Of <(T>)>) Class

[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]

Represents a dynamic data collection that provides notifications when items get added, removed, or when the entire list is refreshed.

Inheritance Hierarchy

System..::.Object
System.Collections.ObjectModel..::.Collection<(Of <(T>)>)
System.Collections.ObjectModel..::.ObservableCollection<(Of <(T>)>)
Microsoft.Phone.Maps.Controls..::.GeoCoordinateCollection
Microsoft.Phone.Maps.Controls..::.MapLayer

Namespace: System.Collections.ObjectModel
Assembly: System (in System.dll)

Syntax

Public Class ObservableCollection(Of T) _
    Inherits Collection(Of T) _
    Implements INotifyCollectionChanged, INotifyPropertyChanged
public class ObservableCollection<T> : Collection<T>, 
    INotifyCollectionChanged, INotifyPropertyChanged

Type Parameters

  • T
    The type of items in the collection.

The ObservableCollection<(Of <(T>)>) type exposes the following members.

Constructors

Name Description
ObservableCollection<(Of <(T>)>)()()() Initializes a new, empty instance of the ObservableCollection<(Of <(T>)>) class.
ObservableCollection<(Of <(T>)>)(IEnumerable<(Of <(T>)>)) Initializes a new instance of the ObservableCollection<(Of <(T>)>) class and populates it with items copied from the specified collection.
ObservableCollection<(Of <(T>)>)(List<(Of <(T>)>)) Initializes a new instance of the ObservableCollection<(Of <(T>)>) class and populates it with items copied from the specified list.

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Properties

Name Description
Count Gets the number of elements actually contained in the Collection<(Of <(T>)>). (Inherited from Collection<(Of <(T>)>).)
Item Gets or sets the element at the specified index. (Inherited from Collection<(Of <(T>)>).)
Items Gets a IList<(Of <(T>)>) wrapper around the Collection<(Of <(T>)>). (Inherited from Collection<(Of <(T>)>).)

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Methods

Name Description
Add Adds an object to the end of the Collection<(Of <(T>)>). (Inherited from Collection<(Of <(T>)>).)
BlockReentrancy Disallows reentrant attempts to change this collection.
CheckReentrancy Checks for reentrant attempts to change this collection.
Clear Removes all elements from the Collection<(Of <(T>)>). (Inherited from Collection<(Of <(T>)>).)
ClearItems Removes all items from the collection. (Overrides Collection<(Of <(T>)>)..::.ClearItems()()().)
Contains Determines whether an element is in the Collection<(Of <(T>)>). (Inherited from Collection<(Of <(T>)>).)
CopyTo Copies the entire Collection<(Of <(T>)>) to a compatible one-dimensional Array, starting at the specified index of the target array. (Inherited from Collection<(Of <(T>)>).)
Equals(Object) Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Finalize Allows an object to try to free resources and perform other cleanup operations before the Object is reclaimed by garbage collection. (Inherited from Object.)
GetEnumerator Returns an enumerator that iterates through the Collection<(Of <(T>)>). (Inherited from Collection<(Of <(T>)>).)
GetHashCode Serves as a hash function for a particular type. (Inherited from Object.)
GetType Gets the Type of the current instance. (Inherited from Object.)
IndexOf Searches for the specified object and returns the zero-based index of the first occurrence within the entire Collection<(Of <(T>)>). (Inherited from Collection<(Of <(T>)>).)
Insert Inserts an element into the Collection<(Of <(T>)>) at the specified index. (Inherited from Collection<(Of <(T>)>).)
InsertItem Inserts an item into the collection at the specified index. (Overrides Collection<(Of <(T>)>)..::.InsertItem(Int32, T).)
MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
Move Moves the item at the specified index to a new location in the collection.
MoveItem Moves the item at the specified index to a new location in the collection.
OnCollectionChanged Raises the CollectionChanged event with the provided event data.
OnPropertyChanged Raises the PropertyChanged event with the provided arguments.
Remove Removes the first occurrence of a specific object from the Collection<(Of <(T>)>). (Inherited from Collection<(Of <(T>)>).)
RemoveAt Removes the element at the specified index of the Collection<(Of <(T>)>). (Inherited from Collection<(Of <(T>)>).)
RemoveItem Removes the item at the specified index from the collection. (Overrides Collection<(Of <(T>)>)..::.RemoveItem(Int32).)
SetItem Replaces the item at the specified index. (Overrides Collection<(Of <(T>)>)..::.SetItem(Int32, T).)
ToString Returns a string that represents the current object. (Inherited from Object.)

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Events

Name Description
CollectionChanged Occurs when an item in the collection changes, or the entire collection changes.
PropertyChanged Occurs when a property on an individual item in the collection changes.

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Explicit Interface Implementations

Name Description
ICollection..::.CopyTo Copies the elements of the ICollection to an Array, starting at a particular Array index. (Inherited from Collection<(Of <(T>)>).)
ICollection<(Of <(T>)>)..::.IsReadOnly Gets a value indicating whether the ICollection<(Of <(T>)>) is read-only. (Inherited from Collection<(Of <(T>)>).)
ICollection..::.IsSynchronized Gets a value indicating whether access to the ICollection is synchronized (thread safe). (Inherited from Collection<(Of <(T>)>).)
ICollection..::.SyncRoot Gets an object that can be used to synchronize access to the ICollection. (Inherited from Collection<(Of <(T>)>).)
IEnumerable..::.GetEnumerator Returns an enumerator that iterates through a collection. (Inherited from Collection<(Of <(T>)>).)
IList..::.Add Adds an item to the IList. (Inherited from Collection<(Of <(T>)>).)
IList..::.Contains Determines whether the IList contains a specific value. (Inherited from Collection<(Of <(T>)>).)
IList..::.IndexOf Determines the index of a specific item in the IList. (Inherited from Collection<(Of <(T>)>).)
IList..::.Insert Inserts an item into the IList at the specified index. (Inherited from Collection<(Of <(T>)>).)
IList..::.IsFixedSize Gets a value indicating whether the IList has a fixed size. (Inherited from Collection<(Of <(T>)>).)
IList..::.IsReadOnly Gets a value indicating whether the IList is read-only. (Inherited from Collection<(Of <(T>)>).)
IList..::.Item Gets or sets the element at the specified index. (Inherited from Collection<(Of <(T>)>).)
IList..::.Remove Removes the first occurrence of a specific object from the IList. (Inherited from Collection<(Of <(T>)>).)
INotifyPropertyChanged..::.PropertyChanged Occurs when a property value changes.

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Remarks

You can enumerate over any collection that implements the IEnumerable interface, and this is sufficient for one-time data binding in XAML. However, to set up dynamic bindings so that insertions or deletions in the collection can update the UI automatically, the collection must implement the INotifyCollectionChanged interface. This interface exposes the CollectionChanged event, an event that should be raised whenever the underlying collection changes.

XAML provides the ObservableCollection<(Of <(T>)>) class, which is a base class data collection that implements the INotifyCollectionChanged interface, as well as the INotifyPropertyChanged interface. It also has the expected collection support, defined by deriving from the Collection<(Of <(T>)>) class.

Version Information

Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

Platforms

Windows Phone

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

See Also

Reference

System.Collections.ObjectModel Namespace