MethodBase.GetMethodBody メソッド

.NET Framework クラス ライブラリ リファレンス

MethodBase.GetMethodBody メソッド

メモ : このメソッドは、.NET Framework version 2.0 で新しく追加されたものです。

派生クラスでオーバーライドされると、現在のメソッドの MSIL ストリーム、ローカル変数、および例外にアクセスできるようにする MethodBody オブジェクトを取得します。

名前空間: System.Reflection
アセンブリ: mscorlib (mscorlib.dll 内)
構文

Visual Basic (宣言)

Public Overridable Function
 GetMethodBody As MethodBody

Visual Basic (使用法)

Dim instance As MethodBase
Dim returnValue As MethodBody

returnValue = instance.GetMethodBody

C#

public virtual MethodBody GetMethodBody ()

C++

public:
virtual MethodBody^ GetMethodBody ()

J#

public MethodBody GetMethodBody ()

JScript

public function GetMethodBody () : MethodBody

戻り値
現在のメソッドの MSIL ストリーム、ローカル変数、および例外にアクセスできるようにする MethodBody オブジェクト。

例外

例外の種類	条件
InvalidOperationException	派生クラスでオーバーライドされない場合、このメソッドは無効です。

解説

GetMethodBody を使用するために、これをオーバーライドする必要はありません。GetMethodBody メソッドは、MethodInfo オブジェクトと ConstructorInfo オブジェクトに対して呼び出すことができます。このメソッドは、これらのクラスの実行時バージョンでオーバーライドされるためです。たとえば、MethodInfo クラスの実行時バージョンは、MethodBase クラスから派生した MethodInfo クラスから派生します。

使用例

MethodBodyExample という名前のテスト メソッドを定義し、ローカル変数の情報と例外処理句を表示するコード例を次に示します。MethodBase.GetMethodBody メソッドは、テスト メソッドの MethodBody オブジェクトを取得するために使用されます。

LocalVariables プロパティを使用して、LocalVariableInfo オブジェクトの一覧を取得し、それらの型とインデックスの順序を表示します。ExceptionHandlingClauses プロパティを使用して、例外処理句の一覧を取得します。

メモ
すべてのコンピュータ言語が ExceptionHandlingClauseOptions.Filter 句を生成できるわけではありません。Visual Basic の例では、Visual Basic の When 式による filter 句が使用されています (他の言語の例では省略されています)。

Visual Basic

Imports System
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

C#

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

C++

#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

プラットフォーム

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

開発プラットフォームの中には、.NET Framework によってサポートされていないバージョンがあります。サポートされているバージョンについては、「システム要件」を参照してください。

バージョン情報

.NET Framework
サポート対象 : 2.0

参照

関連項目
MethodBase クラス
MethodBase メンバ
System.Reflection 名前空間