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IsValueTypeImpl Method
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Type.IsValueTypeImpl Method

Implements the IsValueType property and determines whether the Type is a value type; that is, not a class or an interface.

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

'Declaration
Protected Overridable Function IsValueTypeImpl As Boolean
'Usage
Dim returnValue As Boolean

returnValue = Me.IsValueTypeImpl
protected boolean IsValueTypeImpl ()
protected function IsValueTypeImpl () : boolean
Not applicable.

Return Value

true if the Type is a value type; otherwise, false.

Value types describe values that are represented as sequences of bits; value types are not classes or interfaces. These are referred to as "structs" in some programming languages. Enums are value types.

The following code example demonstrates how to use the IsValueTypeImpl method to change the behavior of the IsValueType property in a derived class.


Imports System
Imports System.Reflection
Imports Microsoft.VisualBasic

Public Class MyTypeDelegator
   Inherits TypeDelegator
   Public myElementType As String = Nothing
   Private myType As Type = Nothing
   
   Public Sub New(myType As Type)
      MyBase.New(myType)
      Me.myType = myType
   End Sub 'New
   
   ' Override the IsValueTypeImpl() method of the Type class.
   Protected Overrides Function IsValueTypeImpl() As Boolean
      ' Determine whether the type is a value type.
      If myType.IsValueType Then
         myElementType = "value"
         Return True
      End If
      ' The type is not a value type.
      Return False
   End Function 'IsValueTypeImpl
End Class 'MyTypeDelegator

Public Class Type_IsValueTypeImpl

   Public Class MyClass1
   End Class 'MyClass1
   
   Public Shared Sub Main()
      Try
         Dim myInt As Integer = 0
         Dim myClass1 As New MyClass1()
         
         Dim myType As New MyTypeDelegator(myInt.GetType())
         Console.WriteLine(ControlChars.NewLine + "Determine whether a variable refers to a value type." + ControlChars.NewLine)
         
         ' Determine whether 'myType' is a value type.  
         If myType.IsValueType Then
            Console.WriteLine(ControlChars.NewLine + "'myInt' is a {0} type.", myType.myElementType)
         Else
            Console.WriteLine(ControlChars.NewLine + "'myInt' is not a value type.")
         End If 
         myType = New MyTypeDelegator(myClass1.GetType())
         
         ' Determine whether 'myType' is a value type.  
         If myType.IsValueType Then
            Console.WriteLine(ControlChars.NewLine + "'myClass1' is a {0} type.", myType.myElementType)
         Else
            Console.WriteLine(ControlChars.NewLine + "'myClass1' is not a value type.")
         End If 
      Catch e As Exception
         Console.WriteLine(ControlChars.NewLine + "The following exception is raised:" + e.Message.ToString())
      End Try
   End Sub 'Main
End Class 'Type_IsValueTypeImpl

import System.*;
import System.Reflection.*;
public class MyTypeDelegator extends TypeDelegator
{
    public String myElementType = null;
    private Type myType = null;

    public MyTypeDelegator(Type myType)
    {
        super(myType);
        this.myType = myType;
    } //MyTypeDelegator

    // Override 'IsValueTypeImpl()' method of 'Type' class.
    protected boolean IsValueTypeImpl()
    {
        // Determine whether the type is a value type.
        if (myType.get_IsValueType()) {
            myElementType = "value";
            return true;
        }
        // The type is not value type.
        return false;
    } //IsValueTypeImpl
} //MyTypeDelegator

public class Type_IsValueTypeImpl
{
    static public class MyClass
    {
    } //MyClass

    public static void main(String[] args)
    {
        try {
            int myInt = 0;
            MyClass myClass = new MyClass();

            MyTypeDelegator myType = new MyTypeDelegator(((System.
                Int32)myInt).GetType());
            Console.WriteLine("\nCheck whether a variable refers to" 
                + " a value type.\n");
            // Determine whether 'myType' is a value type.  
            if (myType.get_IsValueType()) {
                Console.WriteLine("\n'myInt' is a {0} type.",
                    myType.myElementType);
            }
            else {
                Console.WriteLine("\n'myInt' is not a value type.");
            }
            myType = new MyTypeDelegator(myClass.GetType());
            // Determine whether 'myType' is a value type.  
            if (myType.get_IsValueType()) {
                Console.WriteLine("\n'myClass' is a {0} type.",
                    myType.myElementType);
            }
            else {
                Console.WriteLine("\n'myClass' is not a value type.");
            }
        }
        catch (System.Exception e)
        {
            Console.WriteLine("\nThe following exception is raised:" 
                + e.get_Message());
        }
    } //main
} //Type_IsValueTypeImpl

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0

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