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OpCodes.Unbox_Any Field

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

Converts the boxed representation of a type specified in the instruction to its unboxed form.

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

Syntax

'Declaration
Public Shared ReadOnly Unbox_Any As OpCode
public static readonly OpCode Unbox_Any

Remarks

The following table lists the instruction's hexadecimal and Microsoft intermediate language (MSIL) assembly format, along with a brief reference summary:

Format

Assembly Format

Description

A5 < T >

unbox.any typeTok

Extract the data from obj, its boxed representation.

The stack transitional behavior, in sequential order, is:

  1. An object reference obj is pushed onto the stack.

  2. The object reference is popped from the stack and unboxed to the type specified in the instruction.

  3. The resulting object reference or value type is pushed onto the stack.

When applied to the boxed form of a value type, the unbox.any instruction extracts the value contained within obj (of type O), and is therefore equivalent to unbox followed by ldobj.

When applied to a reference type, the unbox.any instruction has the same effect as castclass  typeTok.

If the operand typeTok is a generic type parameter, then the runtime behavior is determined by the type that is specified for that generic type parameter.

InvalidCastException is thrown if obj is not a boxed type.

NullReferenceException is thrown if obj is a null reference.

The following Emit method overload can use the unbox.any opcode:

  • ILGenerator.Emit(OpCode, Type)

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1

Platforms

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