Binder.ChangeType(Object, Type, CultureInfo) Method

Reference

Definition

Namespace:: System.Reflection

Assembly:: System.Runtime.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Source:: Binder.cs

Source:: Binder.cs

Source:: Binder.cs

Important

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

public:
 abstract System::Object ^ ChangeType(System::Object ^ value, Type ^ type, System::Globalization::CultureInfo ^ culture);

public abstract object ChangeType (object value, Type type, System.Globalization.CultureInfo? culture);

public abstract object ChangeType (object value, Type type, System.Globalization.CultureInfo culture);

abstract member ChangeType : obj * Type * System.Globalization.CultureInfo -> obj

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

Parameters

value: Object

The object to change into a new Type.

type: Type

The new Type that value will become.

culture: CultureInfo

An instance of CultureInfo that is used to control the coercion of data types. If culture is null, the CultureInfo for the current thread is used.

Returns

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 does not need special permissions for internal members. Otherwise, the caller needs ReflectionPermission. 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.

If a binder implementation allows coercion of string values to numeric types, the culture parameter is necessary to convert a string that represents 1000 to a Double value, because 1000 is represented differently by different cultures. The default binder does not do such string coercions.

Applies to

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