CallingConvention Enumeration
Assembly: mscorlib (in mscorlib.dll)
'Declaration <SerializableAttribute> _ <ComVisibleAttribute(True)> _ Public Enumeration CallingConvention 'Usage Dim instance As CallingConvention
/** @attribute SerializableAttribute() */ /** @attribute ComVisibleAttribute(true) */ public enum CallingConvention
SerializableAttribute ComVisibleAttribute(true) public enum CallingConvention
| Member name | Description | |
|---|---|---|
| Cdecl | The caller cleans the stack. This enables calling functions with varargs, which makes it appropriate to use for methods that accept a variable number of parameters, such as Printf. | |
| FastCall | This calling convention is not supported. | |
| StdCall | The callee cleans the stack. This is the default convention for calling unmanaged functions with platform invoke. | |
| ThisCall | The first parameter is the this pointer and is stored in register ECX. Other parameters are pushed on the stack. This calling convention is used to call methods on classes exported from an unmanaged DLL. | |
![]() | Winapi | This member is not actually a calling convention, but instead uses the default platform calling convention. For example, on Windows the default is StdCall and on Windows CE.NET it is Cdecl. |
Always use the CallingConvention enumeration rather than the CALLCONV enumeration to specify a calling convention in managed code. The latter exists only for the sake of COM definitions. The CallingConvention enumeration is used by DllImportAttribute and several classes in System.Reflection.Emit to dynamically emit platform invoke signatures.
The following example demonstrates how to apply the Cdecl calling convention, which you must use because the stack is cleaned up by the caller.
Imports System Imports Microsoft.VisualBasic Imports System.Runtime.InteropServices Public Class LibWrap ' Visual Basic does not support varargs, so all arguments must be ' explicitly defined. CallingConvention.Cdecl must be used since the stack ' is cleaned up by the caller. ' int printf( const char *format [, argument]... ) <DllImport("msvcrt.dll", CallingConvention := CallingConvention.Cdecl)> _ Overloads Shared Function printf ( _ format As String, i As Integer, d As Double) As Integer End Function <DllImport("msvcrt.dll", CallingConvention := CallingConvention.Cdecl)> _ Overloads Shared Function printf ( _ format As String, i As Integer, s As String) As Integer End Function End Class 'LibWrap Public Class App Public Shared Sub Main() LibWrap.printf(ControlChars.CrLf + "Print params: %i %f", 99, _ 99.99) LibWrap.printf(ControlChars.CrLf + "Print params: %i %s", 99, _ "abcd") End Sub 'Main End Class 'App
import System.*;
import System.Runtime.InteropServices.*;
public class LibWrap
{
// VJ# doesn't support varargs so all arguments must be explicitly defined.
// CallingConvention.Cdecl must be used since the stack is
// cleaned up by the caller.
// int printf( const char *format [, argument]... )
/** @attribute DllImport("msvcrt.dll", CharSet = CharSet.Ansi,
CallingConvention = CallingConvention.Cdecl)
*/
public static native int printf(String format, int i, double d);
/** @attribute DllImport("msvcrt.dll", CharSet = CharSet.Ansi,
CallingConvention = CallingConvention.Cdecl)
*/
public static native int printf(String format, int i, String s);
} //LibWrap
public class App
{
public static void main(String[] args)
{
LibWrap.printf("\nPrint params: %i %f", 99, 99.99);
LibWrap.printf("\nPrint params: %i %s", 99, "abcd");
} //main
} //App
Windows 98, Windows 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 .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.
