Converter<TInput,TOutput> Delegar

Definição

Representa um método que converte um objeto de um tipo em outro tipo.Represents a method that converts an object from one type to another type.

generic <typename TInput, typename TOutput>
public delegate TOutput Converter(TInput input);
public delegate TOutput Converter<in TInput,out TOutput>(TInput input);
public delegate TOutput Converter<TInput,TOutput>(TInput input);
type Converter<'Input, 'Output> = delegate of 'Input -> 'Output
Public Delegate Function Converter(Of In TInput, Out TOutput)(input As TInput) As TOutput 
Public Delegate Function Converter(Of TInput, TOutput)(input As TInput) As TOutput 

Parâmetros de tipo

TInput

O tipo de objeto a ser convertido.The type of object that is to be converted.

Este parâmetro de tipo é contravariante. Isso significa que é possível usar o tipo especificado ou qualquer tipo menos derivado. Para obter mais informações sobre covariância e contravariância, consulte Covariância e contravariância em genéricos.
TOutput

O tipo para o qual o objeto de entrada será convertido.The type the input object is to be converted to.

Este parâmetro de tipo é covariante. Isso significa que é possível usar o tipo especificado ou qualquer tipo mais derivado. Para obter mais informações sobre covariância e contravariância, consulte Covariância e contravariância em genéricos.

Parâmetros

input
TInput

O objeto a ser convertido.The object to convert.

Valor Retornado

TOutput

O TOutput que representa o TInput convertido.The TOutput that represents the converted TInput.

Exemplos

Esta seção contém dois exemplos de código.This section contains two code examples. O primeiro demonstra o Converter<TInput,TOutput> delegado com o ConvertAll método da Array classe e o segundo demonstra o delegado com o ConvertAll método da List<T> classe genérica.The first demonstrates the Converter<TInput,TOutput> delegate with the ConvertAll method of the Array class, and the second demonstrates the delegate with the ConvertAll method of the List<T> generic class.

Exemplo 1Example 1

O exemplo de código a seguir define um método chamado PointFToPoint que converte uma PointF estrutura em uma Point estrutura.The following code example defines a method named PointFToPoint that converts a PointF structure to a Point structure. Em seguida, o exemplo cria uma matriz de PointF estruturas, cria um Converter<PointF, Point> delegado ( Converter(Of PointF, Point) em Visual Basic) para representar o PointFToPoint método e passa o delegado para o ConvertAll método.The example then creates an array 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. O ConvertAll método passa cada elemento da lista de entrada para o PointFToPoint método e coloca os elementos convertidos em uma nova lista de Point estruturas.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. Ambas as listas são exibidas.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()
{
    // Create an array of PointF objects.
    array<PointF>^ apf = {
        PointF(27.8F, 32.62F),
        PointF(99.3F, 147.273F),
        PointF(7.5F, 1412.2F) };


    // Display each element in the PointF array.
    Console::WriteLine();
    for each(PointF p in apf)
    {
        Console::WriteLine(p);
    }

    // Convert each PointF element to a Point object.
    array<Point>^ ap = 
        Array::ConvertAll(apf, 
            gcnew Converter<PointF, Point>(PointFToPoint)
        );

    // Display each element in the Point array.
    Console::WriteLine();
    for each(Point p in ap)
    {
        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()
    {
        // Create an array of PointF objects.
        PointF[] apf = {
            new PointF(27.8F, 32.62F),
            new PointF(99.3F, 147.273F),
            new PointF(7.5F, 1412.2F) };

        // Display each element in the PointF array.
        Console.WriteLine();
        foreach( PointF p in apf )
            Console.WriteLine(p);

        // Convert each PointF element to a Point object.
        Point[] ap = Array.ConvertAll(apf,
            new Converter<PointF, Point>(PointFToPoint));

        // Display each element in the Point array.
        Console.WriteLine();
        foreach( Point p in ap )
        {
            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()
        ' Create an array of PointF objects.
        Dim apf() As PointF = { _
            New PointF(27.8, 32.62), _
            New PointF(99.3, 147.273), _
            New PointF(7.5, 1412.2)  }

        ' Display each element in the PointF array.
        Console.WriteLine()
        For Each p As PointF In apf
            Console.WriteLine(p)
        Next
        
        ' Convert each PointF element to a Point object.
        Dim ap() As Point = Array.ConvertAll(apf, _
            New Converter(Of PointF, Point)(AddressOf PointFToPoint))

        ' Display each element in the Point array.
        Console.WriteLine()
        For Each p As Point In ap
            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
' The 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}

Exemplo 2Example 2

O exemplo de código a seguir define um método chamado PointFToPoint que converte uma PointF estrutura em uma Point estrutura.The following code example defines a method named PointFToPoint that converts a PointF structure to a Point structure. Em seguida, o exemplo cria uma List<T> das PointF estruturas, cria um Converter\<PointF, Point> delegado ( Converter(Of PointF, Point) em Visual Basic) para representar o PointFToPoint método e passa o delegado para o ConvertAll método.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. O ConvertAll método passa cada elemento da lista de entrada para o PointFToPoint método e coloca os elementos convertidos em uma nova lista de Point estruturas.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. Ambas as listas são exibidas.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}

Comentários

Esse delegado é usado pelo ConvertAll método da Array classe e o ConvertAll método da List<T> classe para converter cada elemento da coleção de um tipo para outro.This delegate is used by the ConvertAll method of the Array class and the ConvertAll method of the List<T> class to convert each element of the collection from one type to another.

Métodos de Extensão

GetMethodInfo(Delegate)

Obtém um objeto que representa o método representado pelo delegado especificado.Gets an object that represents the method represented by the specified delegate.

Aplica-se a