MethodBody.InitLocals Property


Gets a value indicating whether local variables in the method body are initialized to the default values for their types.

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

Public Overridable ReadOnly Property InitLocals As Boolean

Property Value

Type: System.Boolean

true if the method body contains code to initialize local variables to null for reference types, or to the zero-initialized value for value types; otherwise, false.

The InitLocals property refers to variables that are not explicitly initialized; that is, variables that are declared with syntax such as int x; in C# or Dim x As Integer in Visual Basic.

Reference variables are initialized to null by default. Numeric variables are initialized to zero.

The following code example defines a test method named MethodBodyExample and displays its local variable information and exception-handling clauses. The MethodBase.GetMethodBody method is used to obtain a MethodBody object for the test method. The MaxStackSize and InitLocals properties are displayed.

This code example is part of a larger example provided for the MethodBody class.

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()
        e.MethodBodyExample("String argument")

        ' Get method body information.
        Dim mi As MethodInfo = _
        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}", _
        Console.WriteLine("    Maximum number of items on the operand stack: {0}", _
    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"

            ' 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}", _

            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

.NET Framework
Available since 2.0
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