DllImportAttribute.CallingConvention Campo

Definizione

Indica la convenzione di chiamata di un punto di ingresso.Indicates the calling convention of an entry point.

public: System::Runtime::InteropServices::CallingConvention CallingConvention;
public System.Runtime.InteropServices.CallingConvention CallingConvention;
val mutable CallingConvention : System.Runtime.InteropServices.CallingConvention
Public CallingConvention As CallingConvention 

Valore del campo

Esempi

In alcuni casi, Visual Basic sviluppatori utilizzano DllImportAttribute, anziché l' Declare istruzione, per definire una funzione di dll nel codice gestito.In some cases, Visual Basic developers use the DllImportAttribute, instead of the Declare statement, to define a DLL function in managed code. L'impostazione CallingConvention del campo è uno di questi casi.Setting the CallingConvention field is one of those cases.

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

Commenti

Questo campo viene impostato su uno dei membri CallingConvention dell'enumerazione.You set this field to one of the CallingConvention enumeration members. Il valore predefinito per il CallingConvention campo è Winapi, che a sua volta imposta come StdCall predefinito la convenzione.The default value for the CallingConvention field is Winapi, which in turn defaults to StdCall convention.

Si applica a

Vedi anche