MethodBody MethodBody MethodBody MethodBody Class

Определение

Предоставляет доступ к метаданным и MSIL для тела метода.Provides access to the metadata and MSIL for the body of a method.

public ref class MethodBody
[System.Runtime.InteropServices.ComVisible(true)]
public class MethodBody
type MethodBody = class
Public Class MethodBody
Наследование
MethodBodyMethodBodyMethodBodyMethodBody
Атрибуты

Примеры

В следующем примере кода определяется метод теста с именем MethodBodyExample и отображаются сведения о его локальной переменной и предложениях по обработке исключений.The following code example defines a test method named MethodBodyExample and displays its local variable information and exception-handling clauses. Метод используется для MethodBody получения объекта для метода теста. MethodBase.GetMethodBodyThe MethodBase.GetMethodBody method is used to obtain a MethodBody object for the test method.

В примере LocalVariables свойство используется для получения LocalVariableInfo списка объектов, а затем для отображения их типов и порядка индексов.The example uses the LocalVariables property to obtain a list of LocalVariableInfo objects and then displays their types and index order. ExceptionHandlingClauses Свойство используется для получения списка предложений обработки исключений.The ExceptionHandlingClauses property is used to obtain a list of exception-handling clauses.

Примечание

Не все языки компьютеров могут создавать ExceptionHandlingClauseOptions.Filter предложения.Not all computer languages can generate ExceptionHandlingClauseOptions.Filter clauses. В Visual Basic примере показано предложение фильтра с помощью выражения Visual Basic When , которое опускается из примеров для других языков.The Visual Basic example shows a filter clause, using a Visual Basic When expression, which is omitted from the examples for other languages.

#using <System.dll>

using namespace System;
using namespace System::Reflection;

public ref class Example
{
    // The Main method contains code to analyze this method, using
    // the properties and methods of the MethodBody class.
public:
    void MethodBodyExample(Object^ arg)
    {
        // Define some local variables. In addition to these variables,
        // the local variable list includes the variables scoped to 
        // the catch clauses.
        int var1 = 42;
        String^ var2 = "Forty-two";

        try
        {
            // Depending on the input value, throw an ArgumentException or 
            // an ArgumentNullException to test the Catch clauses.
            if (arg == nullptr)
            {
                throw gcnew ArgumentNullException("The argument cannot " +
                    "be null.");
            }
            if (arg->GetType() == String::typeid)
            {
                throw gcnew ArgumentException("The argument cannot " + 
                    "be a string.");
            }        
        }

        // There is no Filter clause in this code example. See the Visual 
        // Basic code for an example of a Filter clause.

        // This catch clause handles the ArgumentException class, and
        // any other class derived from Exception.
        catch (ArgumentException^ ex)
        {
            Console::WriteLine("Ordinary exception-handling clause caught:" +
                " {0}", ex->GetType());
        }        
        finally
        {
            var1 = 3033;
            var2 = "Another string.";
        }
    }
};

int main()
{ 
    // Get method body information.
    MethodInfo^ mi = 
        Example::typeid->GetMethod("MethodBodyExample");

    MethodBody^ mb = mi->GetMethodBody();
    Console::WriteLine("\r\nMethod: {0}", mi);

    // Display the general information included in the 
    // MethodBody object.
    Console::WriteLine("    Local variables are initialized: {0}", 
        mb->InitLocals);
    Console::WriteLine("    Maximum number of items on the operand " +
        "stack: {0}", mb->MaxStackSize);

    // Display information about the local variables in the
    // method body.
    Console::WriteLine();
    for each (LocalVariableInfo^ lvi in mb->LocalVariables)
    {
        Console::WriteLine("Local variable: {0}", lvi);
    }

    // Display exception handling clauses.
    Console::WriteLine();
    for each(ExceptionHandlingClause^ exhc in mb->ExceptionHandlingClauses)
    {
        Console::WriteLine(exhc->Flags.ToString());

        // The FilterOffset property is meaningful only for Filter
        // clauses. The CatchType property is not meaningful for 
        // Filter or Finally clauses. 
        switch(exhc->Flags)
        {
        case ExceptionHandlingClauseOptions::Filter:
            Console::WriteLine("        Filter Offset: {0}", 
                exhc->FilterOffset);
            break;
        case ExceptionHandlingClauseOptions::Finally:
            break;
        default:
            Console::WriteLine("    Type of exception: {0}", 
                exhc->CatchType);
            break;
        }

        Console::WriteLine("       Handler Length: {0}",
            exhc->HandlerLength);
        Console::WriteLine("       Handler Offset: {0}", 
            exhc->HandlerOffset);
        Console::WriteLine("     Try Block Length: {0}", exhc->TryLength);
        Console::WriteLine("     Try Block Offset: {0}", exhc->TryOffset);
    }
}

//This code example produces output similar to the following:
//
//Method: Void MethodBodyExample(System.Object)
//    Local variables are initialized: False
//    Maximum number of items on the operand stack: 4
//
//Local variable: System.ArgumentException (0)
//Local variable: System.String (1)
//Local variable: System.Int32 (2)
//Clause
//    Type of exception: System.ArgumentException
//       Handler Length: 29
//       Handler Offset: 78
//     Try Block Length: 65
//     Try Block Offset: 13
//Finally
//       Handler Length: 13
//       Handler Offset: 113
//     Try Block Length: 100
//     Try Block Offset: 13
using System;
using System.Reflection;

public class Example
{
    public static void Main()
    {
        // Get method body information.
        MethodInfo mi = typeof(Example).GetMethod("MethodBodyExample");
        MethodBody mb = mi.GetMethodBody();
        Console.WriteLine("\r\nMethod: {0}", mi);

        // Display the general information included in the 
        // MethodBody object.
        Console.WriteLine("    Local variables are initialized: {0}", 
            mb.InitLocals);
        Console.WriteLine("    Maximum number of items on the operand stack: {0}", 
            mb.MaxStackSize);

        // Display information about the local variables in the
        // method body.
        Console.WriteLine();
        foreach (LocalVariableInfo lvi in mb.LocalVariables)
        {
            Console.WriteLine("Local variable: {0}", lvi);
        }

        // Display exception handling clauses.
        Console.WriteLine();
        foreach (ExceptionHandlingClause ehc in mb.ExceptionHandlingClauses)
        {
            Console.WriteLine(ehc.Flags.ToString());

            // The FilterOffset property is meaningful only for Filter
            // clauses. The CatchType property is not meaningful for 
            // Filter or Finally clauses. 
            switch (ehc.Flags)
            {
                case ExceptionHandlingClauseOptions.Filter:
                    Console.WriteLine("        Filter Offset: {0}", 
                        ehc.FilterOffset);
                    break;
                case ExceptionHandlingClauseOptions.Finally:
                    break;
                default:
                    Console.WriteLine("    Type of exception: {0}", 
                        ehc.CatchType);
                    break;
            }

            Console.WriteLine("       Handler Length: {0}", ehc.HandlerLength);
            Console.WriteLine("       Handler Offset: {0}", ehc.HandlerOffset);
            Console.WriteLine("     Try Block Length: {0}", ehc.TryLength);
            Console.WriteLine("     Try Block Offset: {0}", ehc.TryOffset);
        }
    }

    // The Main method contains code to analyze this method, using
    // the properties and methods of the MethodBody class.
    public void MethodBodyExample(object arg)
    {
        // Define some local variables. In addition to these variables,
        // the local variable list includes the variables scoped to 
        // the catch clauses.
        int var1 = 42;
        string var2 = "Forty-two";

        try
        {
            // Depending on the input value, throw an ArgumentException or 
            // an ArgumentNullException to test the Catch clauses.
            if (arg == null)
            {
                throw new ArgumentNullException("The argument cannot be null.");
            }
            if (arg.GetType() == typeof(string))
            {
                throw new ArgumentException("The argument cannot be a string.");
            }        
        }

        // There is no Filter clause in this code example. See the Visual 
        // Basic code for an example of a Filter clause.

        // This catch clause handles the ArgumentException class, and
        // any other class derived from Exception.
        catch(Exception ex)
        {
            Console.WriteLine("Ordinary exception-handling clause caught: {0}", 
                ex.GetType());
        }        
        finally
        {
            var1 = 3033;
            var2 = "Another string.";
        }
    }
}

// This code example produces output similar to the following:
//
//Method: Void MethodBodyExample(System.Object)
//    Local variables are initialized: True
//    Maximum number of items on the operand stack: 2
//
//Local variable: System.Int32 (0)
//Local variable: System.String (1)
//Local variable: System.Exception (2)
//Local variable: System.Boolean (3)
//
//Clause
//    Type of exception: System.Exception
//       Handler Length: 21
//       Handler Offset: 70
//     Try Block Length: 61
//     Try Block Offset: 9
//Finally
//       Handler Length: 14
//       Handler Offset: 94
//     Try Block Length: 85
//     Try Block Offset: 9
Imports System.Reflection

Public Class Example

    Public Shared Sub Main()

        ' Demonstrate the effect of the Visual Basic When keyword, which
        ' generates a Filter clause in the Try block.
        Dim e As New Example()
        Console.WriteLine()
        e.MethodBodyExample("String argument")
        e.MethodBodyExample(Nothing)

        ' Get method body information.
        Dim mi As MethodInfo = _
            GetType(Example).GetMethod("MethodBodyExample")
        Dim mb As MethodBody = mi.GetMethodBody()
        Console.WriteLine(vbCrLf & "Method: {0}", mi)

        ' Display the general information included in the 
        ' MethodBody object.
        Console.WriteLine("    Local variables are initialized: {0}", _
            mb.InitLocals)
        Console.WriteLine("    Maximum number of items on the operand stack: {0}", _
            mb.MaxStackSize)

        ' Display information about the local variables in the
        ' method body.
        Console.WriteLine()
        For Each lvi As LocalVariableInfo In mb.LocalVariables
            Console.WriteLine("Local variable: {0}", lvi)
        Next

        ' Display exception handling clauses.
        Console.WriteLine()
        For Each ehc As ExceptionHandlingClause In mb.ExceptionHandlingClauses
            Console.WriteLine(ehc.Flags.ToString())

            ' The FilterOffset property is meaningful only for Filter
            ' clauses. The CatchType property is not meaningful for 
            ' Filter or Finally clauses. 
            Select Case ehc.Flags
                Case ExceptionHandlingClauseOptions.Filter
                    Console.WriteLine("        Filter Offset: {0}", _
                        ehc.FilterOffset)
                Case ExceptionHandlingClauseOptions.Finally
                Case Else
                    Console.WriteLine("    Type of exception: {0}", _
                        ehc.CatchType)
            End Select

            Console.WriteLine("       Handler Length: {0}", ehc.HandlerLength)
            Console.WriteLine("       Handler Offset: {0}", ehc.HandlerOffset)
            Console.WriteLine("     Try Block Length: {0}", ehc.TryLength)
            Console.WriteLine("     Try Block Offset: {0}", ehc.TryOffset)
        Next
    End Sub

    ' This test method is executed at the beginning of Main, to show
    ' how the Filter clause works. The Filter clause is generated by 
    ' a Visual Basic When expression. If arg is Nothing, this method
    ' throws ArgumentNullException, which is caught by the filter
    ' clause. If arg is a string, the method throws ArgumentException,
    ' which does not match the filter clause.
    '
    ' Sub Main also contains code to analyze this method, using 
    ' the properties and methods of the MethodBody class.
    Public Sub MethodBodyExample(ByVal arg As Object)

        ' Define some local variables. In addition to these variables,
        ' the local variable list includes the variables scoped to 
        ' the catch clauses.
        Dim var1 As Integer = 42
        Dim var2 As String = "Forty-two"

        Try
            ' Depending on the input value, throw an ArgumentException or 
            ' an ArgumentNullException to test the Catch clauses.
            '
            If arg Is Nothing Then
                Throw New ArgumentNullException("The argument cannot be Nothing.")
            End If
            If arg.GetType() Is GetType(String) Then
                Throw New ArgumentException("The argument cannot be a string.")
            End If
        
        ' The When expression makes this a filter clause. The expression 
        ' selects only exceptions that derive from the ArgumentException
        ' class. Other exceptions, including ArgumentException itself, 
        ' are not handled by this filter clause.
        Catch ex As ArgumentException _
            When ex.GetType().IsSubclassOf(GetType(ArgumentException))

            Console.WriteLine("Filter clause caught: {0}", ex.GetType())
        
        ' This catch clause handles the ArgumentException class, and
        ' any other class derived from Exception.
        Catch ex As Exception
            Console.WriteLine("Ordinary exception-handling clause caught: {0}", _
                ex.GetType())

        Finally
            var1 = 3033
            var2 = "Another string."
        End Try
    End Sub
End Class

' This code example produces output similar to the following:
'
'Ordinary exception-handling clause caught: System.ArgumentException
'Filter clause caught: System.ArgumentNullException
'
'Method: Void MethodBodyExample(System.Object)
'    Local variables are initialized: True
'    Maximum number of items on the operand stack: 3
'
'Local variable: System.Int32 (0)
'Local variable: System.String (1)
'Local variable: System.ArgumentException (2)
'Local variable: System.Exception (3)
'
'Filter
'        Filter Offset: 0
'       Handler Length: 19
'       Handler Offset: 99
'     Try Block Length: 45
'     Try Block Offset: 9
'Clause
'    Type of exception: System.Exception
'       Handler Length: 25
'       Handler Offset: 118
'     Try Block Length: 45
'     Try Block Offset: 9
'Finally
'       Handler Length: 13
'       Handler Offset: 153
'     Try Block Length: 144
'     Try Block Offset: 9

Комментарии

MethodBody Класс предоставляет доступ к сведениям о локальных переменных и предложениях обработки исключений в теле метода и на языке MSIL, составляющем тело метода.The MethodBody class provides access to information about the local variables and exception-handling clauses in a method body, and to the Microsoft intermediate language (MSIL) that makes up the method body.

Можно использовать методы разрешения ResolveTypeтокенов класса Module, такие как, ResolveMethodи ResolveType, для разрешения токенов в теле метода для Type объектов, MethodInfo объектов и FieldInfo объектов, которые предоставляют подробные сведения о типах, методах и полях, к которым обращается код MSIL в теле метода.You can use the token-resolution methods of the module class, such as ResolveType, ResolveMethod, and ResolveType, to resolve the tokens in the method body to Type objects, MethodInfo objects, and FieldInfo objects that provide detailed information about the types, methods, and fields accessed by the MSIL in the method body.

Примечание

Для анализа тела методов необходимо глубокое понимание метаданных и форматов инструкций MSIL.Parsing method bodies requires a thorough understanding of metadata and MSIL instruction formats. Сведения можно найти в документации по Common Language Infrastructure (CLI), особенно в разделе "Partition II: Определение метаданных и семантика" и "Раздел III. Набор инструкций CIL".Information can be found in the Common Language Infrastructure (CLI) documentation, especially "Partition II: Metadata Definition and Semantics" and "Partition III: CIL Instruction Set". Документация доступна в Интернете; см. страницы ECMAC# и стандарты Common Language Infrastructure на сайте MSDN и Стандарт ECMA-335 — общеязыковая инфраструктура (CLI) на международном веб-сайте организации ECMA.The documentation is available online; see ECMA C# and Common Language Infrastructure Standards on MSDN and Standard ECMA-335 - Common Language Infrastructure (CLI) on the Ecma International Web site.

Чтобы получить MethodBody объект для данного метода, сначала MethodInfo получите объект для MethodInfo метода, GetMethodBody а затем вызовите метод объекта.To obtain a MethodBody object for a given method, first obtain a MethodInfo object for the method, then call the MethodInfo object's GetMethodBody method.

Конструкторы

MethodBody() MethodBody() MethodBody() MethodBody()

Инициализирует новый экземпляр класса MethodBody.Initializes a new instance of the MethodBody class.

Свойства

ExceptionHandlingClauses ExceptionHandlingClauses ExceptionHandlingClauses ExceptionHandlingClauses

Возвращает список, содержащий все предложения обработки исключений в теле метода.Gets a list that includes all the exception-handling clauses in the method body.

InitLocals InitLocals InitLocals InitLocals

Возвращает значение, которое определяет, будут ли локальные переменные в теле метода инициализированы значениями по умолчанию, предусмотренными для соответствующих типов.Gets a value indicating whether local variables in the method body are initialized to the default values for their types.

LocalSignatureMetadataToken LocalSignatureMetadataToken LocalSignatureMetadataToken LocalSignatureMetadataToken

Возвращает токен метаданных для подписи, которая описывает локальные переменные для этого метода в метаданных.Gets a metadata token for the signature that describes the local variables for the method in metadata.

LocalVariables LocalVariables LocalVariables LocalVariables

Возвращает список локальных переменных, объявленных в теле метода.Gets the list of local variables declared in the method body.

MaxStackSize MaxStackSize MaxStackSize MaxStackSize

Возвращает максимальное количество элементов в стеке операторов при выполнении метода.Gets the maximum number of items on the operand stack when the method is executing.

Методы

Equals(Object) Equals(Object) Equals(Object) Equals(Object)

Определяет, равен ли заданный объект текущему объекту.Determines whether the specified object is equal to the current object.

(Inherited from Object)
GetHashCode() GetHashCode() GetHashCode() GetHashCode()

Служит хэш-функцией по умолчанию.Serves as the default hash function.

(Inherited from Object)
GetILAsByteArray() GetILAsByteArray() GetILAsByteArray() GetILAsByteArray()

Возвращает код MSIL тела метода в виде массива байтов.Returns the MSIL for the method body, as an array of bytes.

GetType() GetType() GetType() GetType()

Возвращает объект Type для текущего экземпляра.Gets the Type of the current instance.

(Inherited from Object)
MemberwiseClone() MemberwiseClone() MemberwiseClone() MemberwiseClone()

Создает неполную копию текущего объекта Object.Creates a shallow copy of the current Object.

(Inherited from Object)
ToString() ToString() ToString() ToString()

Возвращает строку, представляющую текущий объект.Returns a string that represents the current object.

(Inherited from Object)

Применяется к