List<T>.ConvertAll<TOutput>(Converter<T,TOutput>) メソッド

定義

現在の List<T> の要素を別の型に変換し、変換された要素が格納されたリストを返します。Converts the elements in the current List<T> to another type, and returns a list containing the converted elements.

public:
generic <typename TOutput>
 System::Collections::Generic::List<TOutput> ^ ConvertAll(Converter<T, TOutput> ^ converter);
public System.Collections.Generic.List<TOutput> ConvertAll<TOutput> (Converter<T,TOutput> converter);
member this.ConvertAll : Converter<'T, 'Output> -> System.Collections.Generic.List<'Output>
Public Function ConvertAll(Of TOutput) (converter As Converter(Of T, TOutput)) As List(Of TOutput)

型パラメーター

TOutput

変換後の配列要素の型。The type of the elements of the target array.

パラメーター

converter
Converter<T,TOutput>

各要素の型を変換するための Converter<TInput,TOutput> デリゲート。A Converter<TInput,TOutput> delegate that converts each element from one type to another type.

戻り値

List<TOutput>

現在の List<T> の要素の型を変換した後の List<T>A List<T> of the target type containing the converted elements from the current List<T>.

例外

converternull です。converter is null.

次の例では、PointF 構造体を Point 構造体に変換する PointFToPoint という名前のメソッドを定義します。The following example defines a method named PointFToPoint that converts a PointF structure to a Point structure. 次に、PointF 構造体の List<T> を作成し、Visual Basic メソッドを表す Converter\<PointF, Point> デリゲート (PointFToPointConverter(Of PointF, Point)) を作成し、そのデリゲートを ConvertAll メソッドに渡します。The example then creates a List<T> of PointF structures, creates a Converter\<PointF, Point> delegate (Converter(Of PointF, Point) in Visual Basic) to represent the PointFToPoint method, and passes the delegate to the ConvertAll method. ConvertAll メソッドは、入力リストの各要素を PointFToPoint メソッドに渡し、変換された要素を Point 構造体の新しいリストに格納します。The ConvertAll method passes each element of the input list to the PointFToPoint method and puts the converted elements into a new list of Point structures. 両方のリストが表示されます。Both lists are displayed.

#using <System.Drawing.dll>

using namespace System;
using namespace System::Drawing;
using namespace System::Collections::Generic;

Point PointFToPoint(PointF pf)
{
    return Point((int) pf.X, (int) pf.Y);
};

void main()
{
    List<PointF>^ lpf = gcnew List<PointF>();

    lpf->Add(PointF(27.8F, 32.62F));
    lpf->Add(PointF(99.3F, 147.273F));
    lpf->Add(PointF(7.5F, 1412.2F));

    Console::WriteLine();
    for each(PointF p in lpf)
    {
        Console::WriteLine(p);
    }

    List<Point>^ lp = 
        lpf->ConvertAll<Point>(
            gcnew Converter<PointF, Point>(PointFToPoint)
        );

    Console::WriteLine();
    for each(Point p in lp)
    {
        Console::WriteLine(p);
    }
}

/* This code example produces the following output:

{X=27.8, Y=32.62}
{X=99.3, Y=147.273}
{X=7.5, Y=1412.2}

{X=27,Y=32}
{X=99,Y=147}
{X=7,Y=1412}
 */
using System;
using System.Drawing;
using System.Collections.Generic;

public class Example
{
    public static void Main()
    {
        List<PointF> lpf = new List<PointF>();

        lpf.Add(new PointF(27.8F, 32.62F));
        lpf.Add(new PointF(99.3F, 147.273F));
        lpf.Add(new PointF(7.5F, 1412.2F));

        Console.WriteLine();
        foreach( PointF p in lpf )
        {
            Console.WriteLine(p);
        }

        List<Point> lp = lpf.ConvertAll( 
            new Converter<PointF, Point>(PointFToPoint));

        Console.WriteLine();
        foreach( Point p in lp )
        {
            Console.WriteLine(p);
        }
    }

    public static Point PointFToPoint(PointF pf)
    {
        return new Point(((int) pf.X), ((int) pf.Y));
    }
}

/* This code example produces the following output:

{X=27.8, Y=32.62}
{X=99.3, Y=147.273}
{X=7.5, Y=1412.2}

{X=27,Y=32}
{X=99,Y=147}
{X=7,Y=1412}
 */
Imports System.Drawing
Imports System.Collections.Generic

Public Class Example

    Public Shared Sub Main()

        Dim lpf As New List(Of PointF)

        lpf.Add(New PointF(27.8, 32.62))
        lpf.Add(New PointF(99.3, 147.273))
        lpf.Add(New PointF(7.5, 1412.2))

        Console.WriteLine()
        For Each p As PointF In lpf
            Console.WriteLine(p)
        Next

        Dim lp As List(Of Point) = lpf.ConvertAll( _
            New Converter(Of PointF, Point)(AddressOf PointFToPoint))

        Console.WriteLine()
        For Each p As Point In lp
            Console.WriteLine(p)
        Next

    End Sub

    Public Shared Function PointFToPoint(ByVal pf As PointF) _
        As Point

        Return New Point(CInt(pf.X), CInt(pf.Y))
    End Function
End Class

' This code example produces the following output:
'
'{X=27.8, Y=32.62}
'{X=99.3, Y=147.273}
'{X=7.5, Y=1412.2}
'
'{X=28,Y=33}
'{X=99,Y=147}
'{X=8,Y=1412}

注釈

Converter<TInput,TOutput> は、オブジェクトを対象の型に変換するメソッドへのデリゲートです。The Converter<TInput,TOutput> is a delegate to a method that converts an object to the target type. 現在の List<T> の要素は、Converter<TInput,TOutput> デリゲートに個別に渡され、変換された要素は新しい List<T>に保存されます。The elements of the current List<T> are individually passed to the Converter<TInput,TOutput> delegate, and the converted elements are saved in the new List<T>.

現在の List<T> は変更されません。The current List<T> remains unchanged.

このメソッドは O (n) 操作です。ここで、 nCountです。This method is an O(n) operation, where n is Count.

適用対象

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