Artikel
11/18/2011

Binder.ChangeType Method

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Changes the type of the given Object to the given Type.

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

Syntax

'Declaration
Public MustOverride Function ChangeType ( _
    value As Object, _
    type As Type, _
    culture As CultureInfo _
) As Object

public abstract Object ChangeType(
    Object value,
    Type type,
    CultureInfo culture
)

Parameters

value
Type: System.Object
The object to change into a new Type.

type
Type: System.Type
The new Type that value will become.

culture
Type: System.Globalization.CultureInfo
An instance of CultureInfo that is used to control the coercion of data types. If culture is nulla null reference (Nothing in Visual Basic), the CultureInfo for the current thread is used.
Note For example, this parameter is necessary to convert a String that represents 1000 to a Double value, because 1000 is represented differently by different cultures.

Return Value

Type: System.Object
An object that contains the given value as the new type.

Remarks

Reflection models the accessibility rules of the common type system. For example, if the caller is in the same assembly, the caller can access internal members. This is consistent with lookup of members that are protected, private, and so on.

The general principle is that ChangeType should perform only widening coercions, which never lose data. An example of a widening coercion is coercing a value that is a 32-bit signed integer to a value that is a 64-bit signed integer. This is distinguished from a narrowing coercion, which may lose data. An example of a narrowing coercion is coercing a 64-bit signed integer to a 32-bit signed integer.

The following table lists the coercions performed by the default ChangeType.

Source type	Target type
Any type	Its base type.
Any type	The interface it implements.
Char	UInt16, UInt32, Int32, UInt64, Int64, Single, Double
Byte	Char, UInt16, Int16, UInt32, Int32, UInt64, Int64, Single, Double
SByte	Int16, Int32, Int64, Single, Double
UInt16	UInt32, Int32, UInt64, Int64, Single, Double
Int16	Int32, Int64, Single, Double
UInt32	UInt64, Int64, Single, Double
Int32	Int64, Single, Double
UInt64	Single, Double
Int64	Single, Double
Single	Double
Non-reference	By-reference.

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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