Enumerable.ToArray(IEnumerable<TSource>) Enumerable.ToArray(IEnumerable<TSource>) Enumerable.ToArray(IEnumerable<TSource>) Enumerable.ToArray(IEnumerable<TSource>) Method

定义

IEnumerable<T> 中创建数组。Creates an array from a IEnumerable<T>.

public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
 static cli::array <TSource> ^ ToArray(System::Collections::Generic::IEnumerable<TSource> ^ source);
public static TSource[] ToArray<TSource> (this System.Collections.Generic.IEnumerable<TSource> source);
static member ToArray : seq<'Source> -> 'Source[]
<Extension()>
Public Function ToArray(Of TSource) (source As IEnumerable(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
IEnumerable<TSource>

要从其创建数组的 IEnumerable<T>An IEnumerable<T> to create an array from.

返回

TSource[]

一个包含输入序列中的元素的数组。An array that contains the elements from the input sequence.

异常

示例

下面的代码示例演示如何使用ToArray以强制进行直接查询计算并返回结果的数组。The following code example demonstrates how to use ToArray to force immediate query evaluation and return an array of results.

class Package
{
    public string Company { get; set; }
    public double Weight { get; set; }
}

public static void ToArrayEx1()
{
    List<Package> packages =
        new List<Package> 
            { new Package { Company = "Coho Vineyard", Weight = 25.2 },
              new Package { Company = "Lucerne Publishing", Weight = 18.7 },
              new Package { Company = "Wingtip Toys", Weight = 6.0 },
              new Package { Company = "Adventure Works", Weight = 33.8 } };

    string[] companies = packages.Select(pkg => pkg.Company).ToArray();

    foreach (string company in companies)
    {
        Console.WriteLine(company);
    }
}

/*
 This code produces the following output:

 Coho Vineyard
 Lucerne Publishing
 Wingtip Toys
 Adventure Works
*/
Structure Package
    Public Company As String
    Public Weight As Double
End Structure

Sub ToArrayEx1()
    ' Create a list of Package values.
    Dim packages As New List(Of Package)(New Package() _
     {New Package With {.Company = "Coho Vineyard", .Weight = 25.2},
      New Package With {.Company = "Lucerne Publishing", .Weight = 18.7},
      New Package With {.Company = "Wingtip Toys", .Weight = 6.0},
      New Package With {.Company = "Adventure Works", .Weight = 33.8}})

    ' Project the Company values from each item in the list
    ' and put them into an array.
    Dim companies() As String =
    packages _
    .Select(Function(pkg) pkg.Company) _
    .ToArray()

    ' Display the results.
    Dim output As New System.Text.StringBuilder
    For Each company As String In companies
        output.AppendLine(company)
    Next
    MsgBox(output.ToString())
End Sub

' This code produces the following output:
'
' Coho Vineyard
' Lucerne Publishing
' Wingtip Toys
' Adventure Works

注解

ToArray<TSource>(IEnumerable<TSource>)方法强制即时的查询进行计算并返回包含查询结果的数组。The ToArray<TSource>(IEnumerable<TSource>) method forces immediate query evaluation and returns an array that contains the query results. 为了获取查询结果的缓存的副本,可以将此方法追加到您的查询。You can append this method to your query in order to obtain a cached copy of the query results.

ToList 具有类似行为,但返回List<T>而不是数组。ToList has similar behavior but returns a List<T> instead of an array.

适用于