Enumerable::Distinct<TSource> Method (IEnumerable<TSource>^, IEqualityComparer<TSource>^)
Returns distinct elements from a sequence by using a specified IEqualityComparer<T> to compare values.
Assembly: System.Core (in System.Core.dll)
public: generic<typename TSource> [ExtensionAttribute] static IEnumerable<TSource>^ Distinct( IEnumerable<TSource>^ source, IEqualityComparer<TSource>^ comparer )
Parameters
- source
-
Type:
System.Collections.Generic::IEnumerable<TSource>^
The sequence to remove duplicate elements from.
- comparer
-
Type:
System.Collections.Generic::IEqualityComparer<TSource>^
An IEqualityComparer<T> to compare values.
Return Value
Type: System.Collections.Generic::IEnumerable<TSource>^An IEnumerable<T> that contains distinct elements from the source sequence.
Type Parameters
- TSource
The type of the elements of source.
| Exception | Condition |
|---|---|
| ArgumentNullException | source is null. |
This method is implemented by using deferred execution. The immediate return value is an object that stores all the information that is required to perform the action. The query represented by this method is not executed until the object is enumerated either by calling its GetEnumerator method directly or by using foreach in Visual C# or For Each in Visual Basic.
The Distinct<TSource>(IEnumerable<TSource>^, IEqualityComparer<TSource>^) method returns an unordered sequence that contains no duplicate values. If comparer is null, the default equality comparer, Default, is used to compare values.
The following example shows how to implement an equality comparer that can be used in the Distinct<TSource> method.
After you implement this comparer, you can use a sequence of Product objects in the Distinct<TSource> method, as shown in the following example.
Available since 8
.NET Framework
Available since 3.5
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1