ParallelEnumerable.Single 方法

定义

返回并行序列的唯一元素;如果该序列并非恰好包含一个元素,则会引发异常。Returns the only element of a parallel sequence, and throws an exception if there is not exactly one element in the sequence.

重载

Single<TSource>(ParallelQuery<TSource>)

返回并行序列的唯一元素;如果该序列并非恰好包含一个元素,则会引发异常。Returns the only element of a parallel sequence, and throws an exception if there is not exactly one element in the sequence.

Single<TSource>(ParallelQuery<TSource>, Func<TSource,Boolean>)

返回并行序列中满足指定条件的唯一元素;如果有多个这样的元素存在,则会引发异常。Returns the only element of a parallel sequence that satisfies a specified condition, and throws an exception if more than one such element exists.

Single<TSource>(ParallelQuery<TSource>)

返回并行序列的唯一元素;如果该序列并非恰好包含一个元素,则会引发异常。Returns the only element of a parallel sequence, and throws an exception if there is not exactly one element in the sequence.

public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
 static TSource Single(System::Linq::ParallelQuery<TSource> ^ source);
public static TSource Single<TSource> (this System.Linq.ParallelQuery<TSource> source);
static member Single : System.Linq.ParallelQuery<'Source> -> 'Source
<Extension()>
Public Function Single(Of TSource) (source As ParallelQuery(Of TSource)) As TSource

类型参数

TSource

source 的元素类型。The type of the elements of source.

参数

source
ParallelQuery<TSource>

要返回其单个元素的序列。The sequence to return the single element of.

返回

TSource

输入序列的单个元素。The single element of the input sequence.

异常

已使用通过 WithCancellation 传递的令牌取消了查询。The query was canceled with the token passed in through WithCancellation.

source 为 null 引用(在 Visual Basic 中为 Nothing)。source is a null reference (Nothing in Visual Basic).

评估查询期间发生一个或多个异常。One or more exceptions occurred during the evaluation of the query.

输入序列包含多个元素。The input sequence contains more than one element. - 或 - 输入序列为空。-or- The input sequence is empty.

另请参阅

Single<TSource>(ParallelQuery<TSource>, Func<TSource,Boolean>)

返回并行序列中满足指定条件的唯一元素;如果有多个这样的元素存在,则会引发异常。Returns the only element of a parallel sequence that satisfies a specified condition, and throws an exception if more than one such element exists.

public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
 static TSource Single(System::Linq::ParallelQuery<TSource> ^ source, Func<TSource, bool> ^ predicate);
public static TSource Single<TSource> (this System.Linq.ParallelQuery<TSource> source, Func<TSource,bool> predicate);
static member Single : System.Linq.ParallelQuery<'Source> * Func<'Source, bool> -> 'Source
<Extension()>
Public Function Single(Of TSource) (source As ParallelQuery(Of TSource), predicate As Func(Of TSource, Boolean)) As TSource

类型参数

TSource

source 的元素类型。The type of the elements of source.

参数

source
ParallelQuery<TSource>

要返回其单个元素的序列。The sequence to return the single element of.

predicate
Func<TSource,Boolean>

用于测试元素是否满足条件的函数。A function to test an element for a condition.

返回

TSource

输入序列中满足条件的单个元素。The single element of the input sequence that satisfies a condition.

异常

已使用通过 WithCancellation 传递的令牌取消了查询。The query was canceled with the token passed in through WithCancellation.

sourcepredicate 为 null 引用(在 Visual Basic 中为 Nothing)。source or predicate is a null reference (Nothing in Visual Basic).

评估查询期间发生一个或多个异常。One or more exceptions occurred during the evaluation of the query.

元素均不满足 predicate 中的条件。No element satisfies the condition in predicate. -或- 多个元素满足 predicate 中的条件。-or- More than one element satisfies the condition in predicate.

另请参阅

适用于