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OpCodes.Endfilter Field

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Transfers control from the filter clause of an exception back to the Common Language Infrastructure (CLI) exception handler.

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

Syntax

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

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

FE 11

endfilter

End filter clause of SEH exception handling.

The stack transitional behavior, in sequential order, is:

  1. value is pushed onto the stack.

  2. value is popped from the stack; endfilter is executed and control is transferred to the exception handler.

Value (which must be of type int32 and is one of a specific set of values) is returned from the filter clause. It should be one of:

  • exception_continue_search (value = 0) to continue searching for an exception handler

  • exception_execute_handler (value = 1) to start the second phase of exception handling where finally blocks are run until the handler associated with this filter clause is located. Upon discovery, the handler is executed.

Other integer values will produce unspecified results.

The entry point of a filter, as shown in the method's exception table, must be the first instruction in the filter's code block. The endfilter instruction must be the last instruction in the filter's code block (hence there can only be one endfilter for any single filter block). After executing the endfilter instruction, control logically flows back to the CLI exception handling mechanism.

Control cannot be transferred into a filter block except through the exception mechanism. Control cannot be transferred out of a filter block except through the use of a throw instruction or by executing the final endfilter instruction. You cannot embed a try block within a filter block. If an exception is thrown inside the filter block, it is intercepted and a value of 0 (exception_continue_search) is returned.

The following Emit method overload can use the endfilter 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.