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public ref class Marshal abstract sealed
public ref class Marshal sealed
public static class Marshal
public sealed class Marshal
type Marshal = class
Public Class Marshal
Public NotInheritable Class Marshal
Inheritance
Marshal
Examples
The following example shows how to use various methods defined by the
Marshal
class.
using namespace System;
using namespace System::Runtime::InteropServices;
public value struct Point
public:
property int X;
property int Y;
extern bool CloseHandle(IntPtr h);
int main()
// Demonstrate the use of public static fields of the Marshal
// class.
Console::WriteLine(
"SystemDefaultCharSize={0},SystemMaxDBCSCharSize={1}",
Marshal::SystemDefaultCharSize,
Marshal::SystemMaxDBCSCharSize);
// Demonstrate the use of the SizeOf method of the Marshal
// class.
Console::WriteLine("Number of bytes needed by a Point object: {0}",
Marshal::SizeOf(Point::typeid));
Point point;
Console::WriteLine("Number of bytes needed by a Point object: {0}",
Marshal::SizeOf(point));
// Demonstrate how to call GlobalAlloc and
// GlobalFree using the Marshal class.
IntPtr hglobal = Marshal::AllocHGlobal(100);
Marshal::FreeHGlobal(hglobal);
// Demonstrate how to use the Marshal class to get the Win32
// error code when a Win32 method fails.
bool isCloseHandleSuccess = CloseHandle(IntPtr(-1));
if (!isCloseHandleSuccess)
Console::WriteLine(
"CloseHandle call failed with an error code of: {0}",
Marshal::GetLastWin32Error());
// This is a platform invoke prototype. SetLastError is true,
// which allows the GetLastWin32Error method of the Marshal class
// to work correctly.
[DllImport("Kernel32", ExactSpelling = true, SetLastError = true)]
extern bool CloseHandle(IntPtr h);
// This code produces the following output.
// SystemDefaultCharSize=2, SystemMaxDBCSCharSize=1
// Number of bytes needed by a Point object: 8
// Number of bytes needed by a Point object: 8
// CloseHandle call failed with an error code of: 6
using System;
using System.Text;
using System.Runtime.InteropServices;
public struct Point
public Int32 x, y;
public sealed class App
static void Main()
// Demonstrate the use of public static fields of the Marshal class.
Console.WriteLine("SystemDefaultCharSize={0}, SystemMaxDBCSCharSize={1}",
Marshal.SystemDefaultCharSize, Marshal.SystemMaxDBCSCharSize);
// Demonstrate the use of the SizeOf method of the Marshal class.
Console.WriteLine("Number of bytes needed by a Point object: {0}",
Marshal.SizeOf(typeof(Point)));
Point p = new Point();
Console.WriteLine("Number of bytes needed by a Point object: {0}",
Marshal.SizeOf(p));
// Demonstrate how to call GlobalAlloc and
// GlobalFree using the Marshal class.
IntPtr hglobal = Marshal.AllocHGlobal(100);
Marshal.FreeHGlobal(hglobal);
// Demonstrate how to use the Marshal class to get the Win32 error
// code when a Win32 method fails.
Boolean f = CloseHandle(new IntPtr(-1));
if (!f)
Console.WriteLine("CloseHandle call failed with an error code of: {0}",
Marshal.GetLastWin32Error());
// This is a platform invoke prototype. SetLastError is true, which allows
// the GetLastWin32Error method of the Marshal class to work correctly.
[DllImport("Kernel32", ExactSpelling = true, SetLastError = true)]
static extern Boolean CloseHandle(IntPtr h);
// This code produces the following output.
// SystemDefaultCharSize=2, SystemMaxDBCSCharSize=1
// Number of bytes needed by a Point object: 8
// Number of bytes needed by a Point object: 8
// CloseHandle call failed with an error code of: 6
Imports System.Text
Imports System.Runtime.InteropServices
Imports System.Security.Permissions
Public Structure Point
Public x, y As Int32
End Structure
Public NotInheritable Class App
<SecurityPermission(SecurityAction.LinkDemand, Unrestricted:=True)> _
Shared Sub Main()
' Demonstrate the use of public static fields of the Marshal class.
Console.WriteLine("SystemDefaultCharSize={0}, SystemMaxDBCSCharSize={1}", Marshal.SystemDefaultCharSize, Marshal.SystemMaxDBCSCharSize)
' Demonstrate the use of the SizeOf method of the Marshal class.
Console.WriteLine("Number of bytes needed by a Point object: {0}", Marshal.SizeOf(GetType(Point)))
Dim p As New Point()
Console.WriteLine("Number of bytes needed by a Point object: {0}", Marshal.SizeOf(p))
' Demonstrate how to call GlobalAlloc and
' GlobalFree using the Marshal class.
Dim hglobal As IntPtr = Marshal.AllocHGlobal(100)
Marshal.FreeHGlobal(hglobal)
' Demonstrate how to use the Marshal class to get the Win32 error
' code when a Win32 method fails.
Dim f As [Boolean] = CloseHandle(New IntPtr(-1))
If Not f Then
Console.WriteLine("CloseHandle call failed with an error code of: {0}", Marshal.GetLastWin32Error())
End If
End Sub
' This is a platform invoke prototype. SetLastError is true, which allows
' the GetLastWin32Error method of the Marshal class to work correctly.
<DllImport("Kernel32", ExactSpelling:=True, SetLastError:=True)> _
Shared Function CloseHandle(ByVal h As IntPtr) As [Boolean]
End Function
End Class
' This code produces the following output.
' SystemDefaultCharSize=2, SystemMaxDBCSCharSize=1
' Number of bytes needed by a Point object: 8
' Number of bytes needed by a Point object: 8
' CloseHandle call failed with an error code of: 6
The
static
methods defined on the
Marshal
class are essential to working with unmanaged code. Most methods defined in this class are typically used by developers who want to provide a bridge between the managed and unmanaged programming models. For example, the
StringToHGlobalAnsi
method copies ANSI characters from a specified string (in the managed heap) to a buffer in the unmanaged heap. It also allocates the target heap of the right size.
The common language runtime provides specific marshaling capabilities. For details on marshaling behavior, see
Interop Marshaling
.
The
Read
and
Write
methods in the
Marshal
class support both aligned and unaligned access.
