OpCodes.Stelem_Ref Field

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Replaces the array element at a given index with the object ref value (type O) on the evaluation stack.

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

Syntax

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

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

A2

stelem.ref

Replaces an array element at the supplied index with the ref value (type O) on the stack.

The stack transitional behavior, in sequential order, is:

  1. An object reference to an array, array, is pushed onto the stack.

  2. A valid index to an element in array is pushed onto the stack.

  3. A value is pushed onto the stack.

  4. The value, the index, and the array reference are popped from the stack; the value is put into the array element at the given index.

The stelem.ref instruction replaces the value of the element at the supplied index in the one-dimensional array array with the ref (type O) value pushed onto the stack.

Arrays are objects and hence represented by a value of type O. The index is type native int.

Note that stelem.ref implicitly casts the supplied value to the element type of array before assigning the value to the array element. This cast can fail, even for verified code. Thus the stelem.ref instruction can throw InvalidCastException. For one-dimensional arrays that aren't zero-based and for multidimensional arrays, the Array class provides a SetValue method.

NullReferenceException is thrown if array is a null reference.

IndexOutOfRangeException is thrown if index is negative, or larger than the bound of array.

ArrayTypeMismatchException is thrown if array does not hold elements of the required type.

The following Emit method overload can use the stelem.ref opcode:

  • ILGenerator.Emit(OpCode)

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.