Enumerable.Contains<'TSource> Method (IEnumerable<'TSource>, 'TSource, IEqualityComparer<'TSource>)
Determines whether a sequence contains a specified element by using a specified IEqualityComparer<'T>.
Assembly: System.Core (in System.Core.dll)
static member Contains<'TSource> : source:IEnumerable<'TSource> * value:'TSource * comparer:IEqualityComparer<'TSource> -> bool
Parameters
- source
-
Type:
System.Collections.Generic.IEnumerable<'TSource>
A sequence in which to locate a value.
- value
-
Type:
TSource
The value to locate in the sequence.
- comparer
-
Type:
System.Collections.Generic.IEqualityComparer<'TSource>
An equality comparer to compare values.
Return Value
Type: System.Booleantrue if the source sequence contains an element that has the specified value; otherwise, false.
Type Parameters
- TSource
The type of the elements of source.
| Exception | Condition |
|---|---|
| ArgumentNullException | source is null. |
Enumeration is terminated as soon as a matching element is found.
If comparer is null, the default equality comparer, Default, is used to compare elements to the specified value.
The following example shows how to implement an equality comparer that can be used in the Contains<'TSource> method.
After you implement this comparer, you can use a sequence of Product objects in the Contains<'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