MethodBody.InitLocals プロパティ

.NET Framework クラス ライブラリ リファレンス

MethodBody.InitLocals プロパティ

メモ : このプロパティは、.NET Framework version 2.0 で新しく追加されたものです。

メソッド本体のローカル変数がその型の既定値に初期化されるかどうかを示す値を取得します。

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

Visual Basic (宣言)

Public ReadOnly Property
 InitLocals As Boolean

Visual Basic (使用法)

Dim instance As MethodBody
Dim value As Boolean

value = instance.InitLocals

C#

public bool InitLocals { get;
 }

C++

public:
property bool InitLocals {
    bool get ();
}

J#

/** @property */
public boolean get_InitLocals ()

JScript

public function get InitLocals
 () : boolean

プロパティ値
ローカル変数を、参照型であれば null 参照 (Visual Basic では Nothing) に、値型であればゼロで初期化された値に初期化するコードがメソッド本体に含まれている場合は true。それ以外の場合は false。

解説

InitLocals プロパティは、明示的に初期化されていない変数を参照します。つまり、構文 (C# での int x; や Visual Basic での Dim x As Integer など) を使用して宣言されている変数を参照します。

参照変数は、既定では null 参照 (Visual Basic では Nothing) に初期化されます。数値変数はゼロに初期化されます。

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および例外処理句を表示するコード例を次に示します。MethodBase.GetMethodBody メソッドを使用して、テスト メソッドの MethodBody オブジェクトを取得します。MaxStackSize プロパティと InitLocals プロパティが表示されます。

このコード例は、MethodBody クラスのトピックで取り上げているコード例の一部分です。

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)
<br /><span space="preserve">...</span><br
 />    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

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);
<br /><span space="preserve">...</span><br /> 
   }

    // 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

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);
<br /><span space="preserve">...</span><br /> 
   // 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.";
        }
    }

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
MethodBody クラス
MethodBody メンバ
System.Reflection 名前空間