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

定義

IEnumerable<T> 建立陣列。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()

類型參數

TSource

source 項目的類型。The type of the elements of source.

參數

source
IEnumerable<TSource>

用來建立陣列的來源 IEnumerable<T>An IEnumerable<T> to create an array from.

傳回

TSource[]

陣列,其中包含輸入序列中的項目。An array that contains the elements from the input sequence.

例外狀況

sourcenullsource is null.

範例

下列程式碼範例示範如何使用 ToArray 來強制立即查詢評估並傳回結果陣列。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
    Console.WriteLine(output.ToString())
End Sub

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

備註

ToArray<TSource>(IEnumerable<TSource>)方法會強制立即查詢評估,並傳回包含查詢結果的陣列。The ToArray<TSource>(IEnumerable<TSource>) method forces immediate query evaluation and returns an array that contains the query results. 您可以將此方法附加至查詢,以取得查詢結果的快取副本。You can append this method to your query in order to obtain a cached copy of the query results.

ToList 具有類似的行為,但會傳回, List<T> 而不是陣列。ToList has similar behavior but returns a List<T> instead of an array.

適用於