DllImportAttribute.CallingConvention Champ

public: System::Runtime::InteropServices::CallingConvention CallingConvention;

public System.Runtime.InteropServices.CallingConvention CallingConvention;

val mutable CallingConvention : System.Runtime.InteropServices.CallingConvention

Public CallingConvention As CallingConvention 

Valeur de champ

Exemples

Dans certains cas, Visual Basic développeurs utilisent le DllImportAttribute, au lieu de l’instruction Declare, pour définir une fonction DLL dans le code managé. La définition du CallingConvention champ est l’un de ces cas.

using namespace System;
using namespace System::Runtime::InteropServices;

private ref class NativeMethods
{
    // Managed class methods don'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]...)
public:
    [DllImport("msvcrt.dll", CharSet = CharSet::Ansi,
        CallingConvention = CallingConvention::Cdecl)]
    static int printf(String^ format, int i, double d);

    [DllImport("msvcrt.dll", CharSet = CharSet::Ansi,
        CallingConvention = CallingConvention::Cdecl)]
    static int printf(String^ format, int i, String^ s);
};

void main()
{
    NativeMethods::printf("\nPrint params: %i %f", 99, 99.99);
    NativeMethods::printf("\nPrint params: %i %s", 99, "abcd");
}

using System;
using System.Runtime.InteropServices;

internal static class NativeMethods
{
    // C# 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]...)
    [DllImport("msvcrt.dll", CharSet = CharSet.Ansi,
        CallingConvention = CallingConvention.Cdecl)]
    internal static extern int printf(string format, int i, double d);

    [DllImport("msvcrt.dll", CharSet = CharSet.Ansi,
        CallingConvention = CallingConvention.Cdecl)]
    internal static extern int printf(string format, int i, string s);
}

public class App
{
    public static void Main()
    {
        NativeMethods.printf("\nPrint params: %i %f", 99, 99.99);
        NativeMethods.printf("\nPrint params: %i %s", 99, "abcd");
    }
}

Imports System.Runtime.InteropServices

Friend Class NativeMethods
    ' Visual Basic 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]...)
    <DllImport("msvcrt.dll", CharSet:=CharSet.Ansi,
        CallingConvention:=CallingConvention.Cdecl)>
    Friend Shared Function printf(format As String, i As Integer, d As Double) As Integer
    End Function
    <DllImport("msvcrt.dll", CharSet:=CharSet.Ansi,
        CallingConvention:=CallingConvention.Cdecl)>
    Friend Shared Function printf(format As String, i As Integer, s As String) As Integer
    End Function
End Class

Public Class App
    Public Shared Sub Main()
        NativeMethods.printf(vbCrLf + "Print params: %i %f", 99, 99.99)
        NativeMethods.printf(vbCrLf + "Print params: %i %s", 99, "abcd")
    End Sub
End Class

Remarques

Vous définissez ce champ sur l’un CallingConvention des membres d’énumération. La valeur par défaut du champ CallingConvention est Winapi, qui, à son tour, est définie sur StdCall convention sur Windows et Cdecl sur toutes les autres plateformes.

Voir aussi

• CallingConvention