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Represents a method that converts an object from one type to another type.
(in mscorlib.dll)
'Usage
Dim instance As New Converter(Of In TInput, Out TOutput)(AddressOf HandlerMethod)
'Declaration
Public Delegate Function Converter(Of In TInput, Out TOutput) ( _
input As TInput _
) As TOutput
Type Parameters
- in In in 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 Out out 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<(Of <(TInput, TOutput>)>) method of the Array class and the ConvertAll<(Of <(TOutput>)>) method of the List<(Of <(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<(Of <(TInput, TOutput>)>) delegate with the ConvertAll<(Of <(TInput, TOutput>)>) method of the Array class, and the second demonstrates the delegate with the ConvertAll<(Of <(TOutput>)>) method of the List<(Of <(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<(Of <(TInput, TOutput>)>) method. The ConvertAll<(Of <(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.
Imports System
Imports System.Drawing
Imports System.Collections.Generic
Public Class Example
Public Shared Sub Main()
Dim apf() As PointF = { _
New PointF(27.8, 32.62), _
New PointF(99.3, 147.273), _
New PointF(7.5, 1412.2) }
Console.WriteLine()
For Each p As PointF In apf
Console.WriteLine(p)
Next
Dim ap() As Point = Array.ConvertAll(apf, _
New Converter(Of PointF, Point)(AddressOf PointFToPoint))
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
' 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}
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<(Of <(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<(Of <(TOutput>)>) method. The ConvertAll<(Of <(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.
Imports System
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}
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune
The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
.NET Framework
Supported in: 4, 3.5, 3.0, 2.0
.NET Framework Client Profile
Supported in: 4
.NET Compact Framework
Supported in: 3.5, 2.0
XNA Framework
Supported in: 3.0, 2.0, 1.0
Reference