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Converter<TInput, TOutput> Delegate

Represents a method that converts an object from one type to another type.

Namespace:  System
Assembly:  mscorlib (in mscorlib.dll)

generic<typename TInput, typename TOutput>
public delegate TOutput Converter(
	TInput input
)

Type Parameters

in TInput

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.

out TOutput

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
Type: TInput
The object to convert.

Return Value

Type: TOutput
The TOutput that represents the converted TInput.

This delegate is used by the ConvertAll<TInput, TOutput> method of the Array class and the ConvertAll<TOutput> method of the List<T> class to convert each element of the collection from one type to another.

This section contains two code examples. The first demonstrates the Converter<TInput, TOutput> delegate with the ConvertAll<TInput, TOutput> method of the Array class, and the second demonstrates the delegate with the ConvertAll<TOutput> method of the List<T> generic class.

Example 1

The following code example defines a method named PointFToPoint that converts a PointF structure to a Point structure. 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<TInput, TOutput> method. The ConvertAll<TInput, TOutput> method passes each element of the input list to the PointFToPoint method and puts the converted elements into a new list of Point structures. 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()
{
    array<PointF>^ apf = {
        PointF(27.8F, 32.62F),
        PointF(99.3F, 147.273F),
        PointF(7.5F, 1412.2F) };

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

    array<Point>^ ap = 
        Array::ConvertAll(apf, 
            gcnew Converter<PointF, Point>(PointFToPoint)
        );

    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}
 */


Example 2

The following code example defines a method named PointFToPoint that converts a PointF structure to a Point structure. 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<TOutput> method. The ConvertAll<TOutput> method passes each element of the input list to the PointFToPoint method and puts the converted elements into a new list of Point structures. 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}
 */


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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