Enumerable::LongCount<TSource> Method (IEnumerable<TSource>^, Func<TSource, Boolean>^)
.NET Framework (current version)
Returns an Int64 that represents how many elements in a sequence satisfy a condition.
Assembly: System.Core (in System.Core.dll)
public: generic<typename TSource> [ExtensionAttribute] static long long LongCount( IEnumerable<TSource>^ source, Func<TSource, bool>^ predicate )
Parameters
- source
-
Type:
System.Collections.Generic::IEnumerable<TSource>^
An IEnumerable<T> that contains the elements to be counted.
- predicate
-
Type:
System::Func<TSource, Boolean>^
A function to test each element for a condition.
Return Value
Type: System::Int64A number that represents how many elements in the sequence satisfy the condition in the predicate function.
Type Parameters
- TSource
The type of the elements of source.
| Exception | Condition |
|---|---|
| ArgumentNullException | source or predicate is null. |
| OverflowException | The number of matching elements exceeds MaxValue. |
Use this method rather than Count<TSource> when you expect the result to be greater than MaxValue.
In Visual Basic query expression syntax, an Aggregate Into LongCount() clause translates to an invocation of LongCount<TSource>.
Universal Windows Platform
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
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
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