ParallelEnumerable::First<TSource> Method (ParallelQuery<TSource>^, Func<TSource, Boolean>^)
Returns the first element in a parallel sequence that satisfies a specified condition.
Assembly: System.Core (in System.Core.dll)
public: generic<typename TSource> [ExtensionAttribute] static TSource First( ParallelQuery<TSource>^ source, Func<TSource, bool>^ predicate )
Parameters
- source
-
Type:
System.Linq::ParallelQuery<TSource>^
The sequence to return an element from.
- predicate
-
Type:
System::Func<TSource, Boolean>^
A function to test each element for a condition.
Return Value
Type: TSourceThe first element in the sequence that passes the test in the specified predicate function.
Type Parameters
- TSource
The type of the elements of source.
| Exception | Condition |
|---|---|
| OperationCanceledException | The query was canceled with the token passed in through WithCancellation. |
| ArgumentNullException | source or predicate is a null reference (Nothing in Visual Basic). |
| AggregateException | One or more exceptions occurred during the evaluation of the query. |
| InvalidOperationException | No element in source satisfies the condition in predicate. |
If the query is not ordered, then the first element is non-deterministic. For more information, see Order Preservation in PLINQ.
Available since 8
.NET Framework
Available since 4.0
Portable Class Library
Supported in: portable .NET platforms
Windows Phone
Available since 8.1