Converter<TInput,TOutput> Delegate

Definition

Stellt eine Methode dar, die ein Objekt von einem Typ in einen anderen Typ konvertiert.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 

Type Parameters

TInput

Der Typ des umzuwandelnden Objekts.The type of object that is to be converted.

This type parameter is contravariant. That is, you can use either the type you specified or any type that is less derived. For more information about covariance and contravariance, see Covariance and Contravariance in Generics.
TOutput

Der Typ, in den das Eingabeobjekt konvertiert werden soll.The type the input object is to be converted to.

This type parameter is covariant. That is, you can use either the type you specified or any type that is more derived. For more information about covariance and contravariance, see Covariance and Contravariance in Generics.

Parameters

input
TInput

Das zu konvertierende Objekt.The object to convert.

Return Value

TOutput

Die TOutput, die die konvertierte TInput darstellt.The TOutput that represents the converted TInput.

Inheritance
Converter<TInput,TOutput>

Examples

Dieser Abschnitt enthält zwei Codebeispiele.This section contains two code examples. Der erste veranschaulicht den Converter<TInput,TOutput> Delegaten mit der ConvertAll-Methode der Array-Klasse, und der zweite veranschaulicht den Delegaten mit der ConvertAll-Methode der List<T> generischen Klasse.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.

Beispiel 1Example 1

Im folgenden Codebeispiel wird eine Methode mit dem Namen PointFToPoint definiert, die eine PointF-Struktur in eine Point Struktur konvertiert.The following code example defines a method named PointFToPoint that converts a PointF structure to a Point structure. Im Beispiel wird dann ein Array aus PointF Strukturen erstellt, ein Converter<PointF, Point> Delegat (Converter(Of PointF, Point) in Visual Basic) erstellt, um die PointFToPoint-Methode darzustellen, und der-Delegat wird an die ConvertAll-Methode weitergeleitet.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. Die ConvertAll-Methode übergibt jedes Element der Eingabeliste an die PointFToPoint-Methode und fügt die konvertierten Elemente in eine neue Liste von Point Strukturen ein.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. Beide Listen werden angezeigt.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}

Beispiel 2Example 2

Im folgenden Codebeispiel wird eine Methode mit dem Namen PointFToPoint definiert, die eine PointF-Struktur in eine Point Struktur konvertiert.The following code example defines a method named PointFToPoint that converts a PointF structure to a Point structure. Im Beispiel wird dann eine List<T> PointF Strukturen erstellt, ein Converter\<PointF, Point> Delegat (Converter(Of PointF, Point) in Visual Basic) erstellt, um die PointFToPoint-Methode darzustellen, und der-Delegat wird an die ConvertAll-Methode weitergeleitet.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. Die ConvertAll-Methode übergibt jedes Element der Eingabeliste an die PointFToPoint-Methode und fügt die konvertierten Elemente in eine neue Liste von Point Strukturen ein.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. Beide Listen werden angezeigt.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}

Remarks

Dieser Delegat wird von der ConvertAll-Methode der Array-Klasse und der ConvertAll-Methode der List<T>-Klasse verwendet, um jedes Element der Auflistung von einem Typ in einen anderen zu konvertieren.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.

Extension Methods

GetMethodInfo(Delegate)

Ruft ein Objekt ab, das die Methode darstellt, die vom angegebenen Delegaten dargestellt wird.Gets an object that represents the method represented by the specified delegate.

Applies to