# ParallelEnumerable.Average 方法

## 重载

 Average(ParallelQuery) 并行计算一个值序列的平均值。Computes in parallel the average of a sequence of values. Average(ParallelQuery>) 并行计算一个值序列的平均值。Computes in parallel the average of a sequence of values. Average(ParallelQuery>) 并行计算一个值序列的平均值。Computes in parallel the average of a sequence of values. Average(ParallelQuery>) 并行计算一个值序列的平均值。Computes in parallel the average of a sequence of values. Average(ParallelQuery>) 并行计算一个值序列的平均值。Computes in parallel the average of a sequence of values. Average(ParallelQuery) 并行计算一个值序列的平均值。Computes in parallel the average of a sequence of values. Average(ParallelQuery) 并行计算一个值序列的平均值。Computes in parallel the average of a sequence of values. Average(ParallelQuery) 并行计算一个值序列的平均值。Computes in parallel the average of a sequence of values. Average(ParallelQuery) 并行计算一个值序列的平均值。Computes in parallel the average of a sequence of values. Average(ParallelQuery>) 并行计算一个值序列的平均值。Computes in parallel the average of a sequence of values. Average(ParallelQuery, Func) 并行计算一个值序列的平均值，这些值可通过对输入序列的每个元素调用转换函数获得。Computes in parallel the average of a sequence of values that are obtained by invoking a transform function on each element of the input sequence. Average(ParallelQuery, Func>) 并行计算一个值序列的平均值，这些值可通过对输入序列的每个元素调用转换函数获得。Computes in parallel the average of a sequence of values that are obtained by invoking a transform function on each element of the input sequence. Average(ParallelQuery, Func>) 并行计算一个值序列的平均值，这些值可通过对输入序列的每个元素调用转换函数获得。Computes in parallel the average of a sequence of values that are obtained by invoking a transform function on each element of the input sequence. Average(ParallelQuery, Func>) 并行计算一个值序列的平均值，这些值可通过对输入序列的每个元素调用转换函数获得。Computes in parallel the average of a sequence of values that are obtained by invoking a transform function on each element of the input sequence. Average(ParallelQuery, Func>) 并行计算一个值序列的平均值，这些值可通过对输入序列的每个元素调用转换函数获得。Computes in parallel the average of a sequence of values that are obtained by invoking a transform function on each element of the input sequence. Average(ParallelQuery, Func) 并行计算一个值序列的平均值，这些值可通过对输入序列的每个元素调用转换函数获得。Computes in parallel the average of a sequence of values that are obtained by invoking a transform function on each element of the input sequence. Average(ParallelQuery, Func) 并行计算一个值序列的平均值，这些值可通过对输入序列的每个元素调用转换函数获得。Computes in parallel the average of a sequence of values that are obtained by invoking a transform function on each element of the input sequence. Average(ParallelQuery, Func) 并行计算一个值序列的平均值，这些值可通过对输入序列的每个元素调用转换函数获得。Computes in parallel the average of a sequence of values that are obtained by invoking a transform function on each element of the input sequence. Average(ParallelQuery, Func) 并行计算一个值序列的平均值，这些值可通过对输入序列的每个元素调用转换函数获得。Computes in parallel the average of a sequence of values that are obtained by invoking a transform function on each element of the input sequence. Average(ParallelQuery, Func>) 并行计算一个值序列的平均值，这些值可通过对输入序列的每个元素调用转换函数获得。Computes in parallel the average of a sequence of values that are obtained by invoking a transform function on each element of the input sequence.

## Average(ParallelQuery<Single>)

``````public:
[System::Runtime::CompilerServices::Extension]
static float Average(System::Linq::ParallelQuery<float> ^ source);``````
``public static float Average (this System.Linq.ParallelQuery<float> source);``
``static member Average : System.Linq.ParallelQuery<single> -> single``
``````<Extension()>
Public Function Average (source As ParallelQuery(Of Single)) As Single``````

#### 参数

source
ParallelQuery<Single>

#### 异常

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

`source` 中不包含任何元素。`source` contains no elements.

## Average(ParallelQuery<Nullable<Int64>>)

``````public:
[System::Runtime::CompilerServices::Extension]
static Nullable<double> Average(System::Linq::ParallelQuery<Nullable<long>> ^ source);``````
``public static Nullable<double> Average (this System.Linq.ParallelQuery<Nullable<long>> source);``
``static member Average : System.Linq.ParallelQuery<Nullable<int64>> -> Nullable<double>``
``````<Extension()>
Public Function Average (source As ParallelQuery(Of Nullable(Of Long))) As Nullable(Of Double)``````

#### 参数

source
ParallelQuery<Nullable<Int64>>

#### 异常

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

`source` 中不包含任何元素。`source` contains no elements.

## Average(ParallelQuery<Nullable<Int32>>)

``````public:
[System::Runtime::CompilerServices::Extension]
static Nullable<double> Average(System::Linq::ParallelQuery<Nullable<int>> ^ source);``````
``public static Nullable<double> Average (this System.Linq.ParallelQuery<Nullable<int>> source);``
``static member Average : System.Linq.ParallelQuery<Nullable<int>> -> Nullable<double>``
``````<Extension()>
Public Function Average (source As ParallelQuery(Of Nullable(Of Integer))) As Nullable(Of Double)``````

#### 参数

source
ParallelQuery<Nullable<Int32>>

#### 异常

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

`source` 中不包含任何元素。`source` contains no elements.

## Average(ParallelQuery<Nullable<Double>>)

``````public:
[System::Runtime::CompilerServices::Extension]
static Nullable<double> Average(System::Linq::ParallelQuery<Nullable<double>> ^ source);``````
``public static Nullable<double> Average (this System.Linq.ParallelQuery<Nullable<double>> source);``
``static member Average : System.Linq.ParallelQuery<Nullable<double>> -> Nullable<double>``
``````<Extension()>
Public Function Average (source As ParallelQuery(Of Nullable(Of Double))) As Nullable(Of Double)``````

#### 参数

source
ParallelQuery<Nullable<Double>>

#### 异常

`source` 中不包含任何元素。`source` contains no elements.

## Average(ParallelQuery<Nullable<Single>>)

``````public:
[System::Runtime::CompilerServices::Extension]
static Nullable<float> Average(System::Linq::ParallelQuery<Nullable<float>> ^ source);``````
``public static Nullable<float> Average (this System.Linq.ParallelQuery<Nullable<float>> source);``
``static member Average : System.Linq.ParallelQuery<Nullable<single>> -> Nullable<single>``
``````<Extension()>
Public Function Average (source As ParallelQuery(Of Nullable(Of Single))) As Nullable(Of Single)``````

#### 参数

source
ParallelQuery<Nullable<Single>>

#### 异常

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

`source` 中不包含任何元素。`source` contains no elements.

## Average(ParallelQuery<Int64>)

``````public:
[System::Runtime::CompilerServices::Extension]
static double Average(System::Linq::ParallelQuery<long> ^ source);``````
``public static double Average (this System.Linq.ParallelQuery<long> source);``
``static member Average : System.Linq.ParallelQuery<int64> -> double``
``````<Extension()>
Public Function Average (source As ParallelQuery(Of Long)) As Double``````

#### 参数

source
ParallelQuery<Int64>

#### 异常

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

`source` 中不包含任何元素。`source` contains no elements.

## Average(ParallelQuery<Int32>)

``````public:
[System::Runtime::CompilerServices::Extension]
static double Average(System::Linq::ParallelQuery<int> ^ source);``````
``public static double Average (this System.Linq.ParallelQuery<int> source);``
``static member Average : System.Linq.ParallelQuery<int> -> double``
``````<Extension()>
Public Function Average (source As ParallelQuery(Of Integer)) As Double``````

#### 参数

source
ParallelQuery<Int32>

#### 异常

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

`source` 中不包含任何元素。`source` contains no elements.

## Average(ParallelQuery<Double>)

``````public:
[System::Runtime::CompilerServices::Extension]
static double Average(System::Linq::ParallelQuery<double> ^ source);``````
``public static double Average (this System.Linq.ParallelQuery<double> source);``
``static member Average : System.Linq.ParallelQuery<double> -> double``
``````<Extension()>
Public Function Average (source As ParallelQuery(Of Double)) As Double``````

#### 参数

source
ParallelQuery<Double>

#### 异常

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

`source` 中不包含任何元素。`source` contains no elements.

## Average(ParallelQuery<Decimal>)

``````public:
[System::Runtime::CompilerServices::Extension]
static System::Decimal Average(System::Linq::ParallelQuery<System::Decimal> ^ source);``````
``public static decimal Average (this System.Linq.ParallelQuery<decimal> source);``
``static member Average : System.Linq.ParallelQuery<decimal> -> decimal``
``````<Extension()>
Public Function Average (source As ParallelQuery(Of Decimal)) As Decimal``````

#### 参数

source
ParallelQuery<Decimal>

#### 异常

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

`source` 中不包含任何元素。`source` contains no elements.

## Average(ParallelQuery<Nullable<Decimal>>)

``````public:
[System::Runtime::CompilerServices::Extension]
static Nullable<System::Decimal> Average(System::Linq::ParallelQuery<Nullable<System::Decimal>> ^ source);``````
``public static Nullable<decimal> Average (this System.Linq.ParallelQuery<Nullable<decimal>> source);``
``static member Average : System.Linq.ParallelQuery<Nullable<decimal>> -> Nullable<decimal>``
``````<Extension()>
Public Function Average (source As ParallelQuery(Of Nullable(Of Decimal))) As Nullable(Of Decimal)``````

#### 参数

source
ParallelQuery<Nullable<Decimal>>

#### 异常

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

`source` 中不包含任何元素。`source` contains no elements.

## Average<TSource>(ParallelQuery<TSource>, Func<TSource,Single>)

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

#### 类型参数

TSource

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

#### 参数

source
ParallelQuery<TSource>

selector
Func<TSource,Single>

#### 异常

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

`source` 中不包含任何元素。`source` contains no elements.

（在 AggregateException 中作为内部异常引发）。(Thrown as inner exception in an AggregateException). `selector` 函数返回一个大于元素类型的 MaxValue 的值。The `selector` function returns a value greater than MaxValue for the element type.

## Average<TSource>(ParallelQuery<TSource>, Func<TSource,Nullable<Int64>>)

``````public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static Nullable<double> Average(System::Linq::ParallelQuery<TSource> ^ source, Func<TSource, Nullable<long>> ^ selector);``````
``public static Nullable<double> Average<TSource> (this System.Linq.ParallelQuery<TSource> source, Func<TSource,Nullable<long>> selector);``
``static member Average : System.Linq.ParallelQuery<'Source> * Func<'Source, Nullable<int64>> -> Nullable<double>``
``````<Extension()>
Public Function Average(Of TSource) (source As ParallelQuery(Of TSource), selector As Func(Of TSource, Nullable(Of Long))) As Nullable(Of Double)``````

#### 类型参数

TSource

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

#### 参数

source
ParallelQuery<TSource>

selector
Func<TSource,Nullable<Int64>>

#### 异常

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

`source` 中不包含任何元素。`source` contains no elements.

（在 AggregateException 中作为内部异常引发）。(Thrown as inner exception in an AggregateException). `selector` 函数返回一个大于元素类型的 MaxValue 的值。The `selector` function returns a value greater than MaxValue for the element type.

## Average<TSource>(ParallelQuery<TSource>, Func<TSource,Nullable<Int32>>)

``````public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static Nullable<double> Average(System::Linq::ParallelQuery<TSource> ^ source, Func<TSource, Nullable<int>> ^ selector);``````
``public static Nullable<double> Average<TSource> (this System.Linq.ParallelQuery<TSource> source, Func<TSource,Nullable<int>> selector);``
``static member Average : System.Linq.ParallelQuery<'Source> * Func<'Source, Nullable<int>> -> Nullable<double>``
``````<Extension()>
Public Function Average(Of TSource) (source As ParallelQuery(Of TSource), selector As Func(Of TSource, Nullable(Of Integer))) As Nullable(Of Double)``````

#### 类型参数

TSource

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

#### 参数

source
ParallelQuery<TSource>

selector
Func<TSource,Nullable<Int32>>

#### 异常

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

`source` 中不包含任何元素。`source` contains no elements.

（在 AggregateException 中作为内部异常引发）。(Thrown as inner exception in an AggregateException). `selector` 函数返回一个大于元素类型的 MaxValue 的值。The `selector` function returns a value greater than MaxValue for the element type.

## Average<TSource>(ParallelQuery<TSource>, Func<TSource,Nullable<Double>>)

``````public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static Nullable<double> Average(System::Linq::ParallelQuery<TSource> ^ source, Func<TSource, Nullable<double>> ^ selector);``````
``public static Nullable<double> Average<TSource> (this System.Linq.ParallelQuery<TSource> source, Func<TSource,Nullable<double>> selector);``
``static member Average : System.Linq.ParallelQuery<'Source> * Func<'Source, Nullable<double>> -> Nullable<double>``
``````<Extension()>
Public Function Average(Of TSource) (source As ParallelQuery(Of TSource), selector As Func(Of TSource, Nullable(Of Double))) As Nullable(Of Double)``````

#### 类型参数

TSource

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

#### 参数

source
ParallelQuery<TSource>

selector
Func<TSource,Nullable<Double>>

#### 异常

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

`source` 中不包含任何元素。`source` contains no elements.

（在 AggregateException 中作为内部异常引发）。(Thrown as inner exception in an AggregateException). `selector` 函数返回一个大于元素类型的 MaxValue 的值。The `selector` function returns a value greater than MaxValue for the element type.

## Average<TSource>(ParallelQuery<TSource>, Func<TSource,Nullable<Single>>)

``````public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static Nullable<float> Average(System::Linq::ParallelQuery<TSource> ^ source, Func<TSource, Nullable<float>> ^ selector);``````
``public static Nullable<float> Average<TSource> (this System.Linq.ParallelQuery<TSource> source, Func<TSource,Nullable<float>> selector);``
``static member Average : System.Linq.ParallelQuery<'Source> * Func<'Source, Nullable<single>> -> Nullable<single>``
``````<Extension()>
Public Function Average(Of TSource) (source As ParallelQuery(Of TSource), selector As Func(Of TSource, Nullable(Of Single))) As Nullable(Of Single)``````

#### 类型参数

TSource

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

#### 参数

source
ParallelQuery<TSource>

selector
Func<TSource,Nullable<Single>>

#### 异常

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

`source` 中不包含任何元素。`source` contains no elements.

（在 AggregateException 中作为内部异常引发）。(Thrown as inner exception in an AggregateException). `selector` 函数返回一个大于元素类型的 MaxValue 的值。The `selector` function returns a value greater than MaxValue for the element type.

## Average<TSource>(ParallelQuery<TSource>, Func<TSource,Int64>)

``````public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static double Average(System::Linq::ParallelQuery<TSource> ^ source, Func<TSource, long> ^ selector);``````
``public static double Average<TSource> (this System.Linq.ParallelQuery<TSource> source, Func<TSource,long> selector);``
``static member Average : System.Linq.ParallelQuery<'Source> * Func<'Source, int64> -> double``
``````<Extension()>
Public Function Average(Of TSource) (source As ParallelQuery(Of TSource), selector As Func(Of TSource, Long)) As Double``````

#### 类型参数

TSource

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

#### 参数

source
ParallelQuery<TSource>

selector
Func<TSource,Int64>

#### 异常

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

`source` 中不包含任何元素。`source` contains no elements.

（在 AggregateException 中作为内部异常引发）。(Thrown as inner exception in an AggregateException). `selector` 函数返回一个大于元素类型的 MaxValue 的值。The `selector` function returns a value greater than MaxValue for the element type.

## Average<TSource>(ParallelQuery<TSource>, Func<TSource,Int32>)

``````public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static double Average(System::Linq::ParallelQuery<TSource> ^ source, Func<TSource, int> ^ selector);``````
``public static double Average<TSource> (this System.Linq.ParallelQuery<TSource> source, Func<TSource,int> selector);``
``static member Average : System.Linq.ParallelQuery<'Source> * Func<'Source, int> -> double``
``````<Extension()>
Public Function Average(Of TSource) (source As ParallelQuery(Of TSource), selector As Func(Of TSource, Integer)) As Double``````

#### 类型参数

TSource

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

#### 参数

source
ParallelQuery<TSource>

selector
Func<TSource,Int32>

#### 异常

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

`source` 中不包含任何元素。`source` contains no elements.

（在 AggregateException 中作为内部异常引发）。(Thrown as inner exception in an AggregateException). `selector` 函数返回一个大于元素类型的 MaxValue 的值。The `selector` function returns a value greater than MaxValue for the element type.

## Average<TSource>(ParallelQuery<TSource>, Func<TSource,Double>)

``````public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static double Average(System::Linq::ParallelQuery<TSource> ^ source, Func<TSource, double> ^ selector);``````
``public static double Average<TSource> (this System.Linq.ParallelQuery<TSource> source, Func<TSource,double> selector);``
``static member Average : System.Linq.ParallelQuery<'Source> * Func<'Source, double> -> double``
``````<Extension()>
Public Function Average(Of TSource) (source As ParallelQuery(Of TSource), selector As Func(Of TSource, Double)) As Double``````

#### 类型参数

TSource

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

#### 参数

source
ParallelQuery<TSource>

selector
Func<TSource,Double>

#### 异常

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

`source` 中不包含任何元素。`source` contains no elements.

（在 AggregateException 中作为内部异常引发）。(Thrown as inner exception in an AggregateException). `selector` 函数返回一个大于元素类型的 MaxValue 的值。The `selector` function returns a value greater than MaxValue for the element type.

## Average<TSource>(ParallelQuery<TSource>, Func<TSource,Decimal>)

``````public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static System::Decimal Average(System::Linq::ParallelQuery<TSource> ^ source, Func<TSource, System::Decimal> ^ selector);``````
``public static decimal Average<TSource> (this System.Linq.ParallelQuery<TSource> source, Func<TSource,decimal> selector);``
``static member Average : System.Linq.ParallelQuery<'Source> * Func<'Source, decimal> -> decimal``
``````<Extension()>
Public Function Average(Of TSource) (source As ParallelQuery(Of TSource), selector As Func(Of TSource, Decimal)) As Decimal``````

#### 类型参数

TSource

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

#### 参数

source
ParallelQuery<TSource>

selector
Func<TSource,Decimal>

#### 异常

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

`source` 中不包含任何元素。`source` contains no elements.

（在 AggregateException 中作为内部异常引发）。(Thrown as inner exception in an AggregateException). `selector` 函数返回一个大于元素类型的 MaxValue 的值。The `selector` function returns a value greater than MaxValue for the element type.

## Average<TSource>(ParallelQuery<TSource>, Func<TSource,Nullable<Decimal>>)

``````public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static Nullable<System::Decimal> Average(System::Linq::ParallelQuery<TSource> ^ source, Func<TSource, Nullable<System::Decimal>> ^ selector);``````
``public static Nullable<decimal> Average<TSource> (this System.Linq.ParallelQuery<TSource> source, Func<TSource,Nullable<decimal>> selector);``
``static member Average : System.Linq.ParallelQuery<'Source> * Func<'Source, Nullable<decimal>> -> Nullable<decimal>``
``````<Extension()>
Public Function Average(Of TSource) (source As ParallelQuery(Of TSource), selector As Func(Of TSource, Nullable(Of Decimal))) As Nullable(Of Decimal)``````

#### 类型参数

TSource

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

#### 参数

source
ParallelQuery<TSource>

selector
Func<TSource,Nullable<Decimal>>

#### 异常

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

`source` 中不包含任何元素。`source` contains no elements.

（在 AggregateException 中作为内部异常引发）。(Thrown as inner exception in an AggregateException). `selector` 函数返回一个大于元素类型的 MaxValue 的值。The `selector` function returns a value greater than MaxValue for the element type.