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Marshal.SizeOf Method (Object)

Note: This API is now obsolete.

Returns the unmanaged size of an object in bytes.

Namespace:  System.Runtime.InteropServices
Assemblies:   System.Runtime.InteropServices (in System.Runtime.InteropServices.dll)
  mscorlib (in mscorlib.dll)

'Declaration
<ObsoleteAttribute("SizeOf(Object) may be unavailable in future releases. Instead, use SizeOf<T>(). For more info, go to http://go.microsoft.com/fwlink/?LinkID=296514")> _
Public Shared Function SizeOf ( _
	structure As Object _
) As Integer

Parameters

structure
Type: System.Object

The object whose size is to be returned.

Return Value

Type: System.Int32
The size of the specified object in unmanaged code.

ExceptionCondition
ArgumentNullException

The structure parameter is Nothing.

This method accepts an instance of a structure, which can be a reference type or a boxed value type. The layout must be sequential or explicit.

The size returned is the size of the unmanaged object. The unmanaged and managed sizes of an object can differ. For character types, the size is affected by the CharSet value applied to that class.

You can use the SizeOf method to determine how much unmanaged memory to allocate using the AllocHGlobal and AllocCoTaskMem methods.

The following example creates a managed structure, transfers it to unmanaged memory, and then transfers it back to managed memory. This example uses the SizeOf method to determine how much unmanaged memory to allocate.

Imports System
Imports System.Runtime.InteropServices



Public Structure Point
    Public x As Integer 
    Public y As Integer 
End Structure 


Module Example


    Sub Main()

        ' Create a point struct. 
        Dim p As Point
        p.x = 1
        p.y = 1

        Console.WriteLine("The value of first point is " + p.x.ToString + " and " + p.y.ToString + ".")

        ' Initialize unmanged memory to hold the struct. 
        Dim pnt As IntPtr = Marshal.AllocHGlobal(Marshal.SizeOf(p))

        Try 

            ' Copy the struct to unmanaged memory.
            Marshal.StructureToPtr(p, pnt, False)

            ' Create another point. 
            Dim anotherP As Point

            ' Set this Point to the value of the  
            ' Point in unmanaged memory. 
            anotherP = CType(Marshal.PtrToStructure(pnt, GetType(Point)), Point)

            Console.WriteLine("The value of new point is " + anotherP.x.ToString + " and " + anotherP.y.ToString + ".")

        Finally 
            ' Free the unmanaged memory.
            Marshal.FreeHGlobal(pnt)
        End Try 

    End Sub 
End Module

.NET Framework

Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0, 1.1
Obsolete (compiler warning) in 4.6

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

XNA Framework

Supported in: 3.0, 2.0, 1.0

Portable Class Library

Supported in: Portable Class Library

Supported in: Windows Phone 8.1

Supported in: Windows Phone Silverlight 8.1

Supported in: Windows Phone Silverlight 8
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