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

定義

命名空間:

System.Linq

組件:

System.Linq.dll

來源:

ToCollection.cs

從 IEnumerable<T> 建立陣列。

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。

參數

source

IEnumerable<TSource>

用來建立陣列的來源 IEnumerable<T>。

傳回

TSource[]

陣列，其中包含輸入序列中的項目。

例外狀況

ArgumentNullException

source 為 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。

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

方法 ToArray<TSource>(IEnumerable<TSource>) 會強制立即查詢評估，並傳回包含查詢結果的陣列。 您可以將這個方法附加至查詢，以取得查詢結果的快取複本。

ToList 具有類似的行為，但會 List<T> 傳回 而非陣列。