Description
The values of this enumeration are used to specify the calling conventions required to call unmanaged methods implemented in shared libraries.
[Note: Implementers should map the semantics of specified calling conventions onto the calling conventions of the host OS.]
[Note: For additional information on shared libraries and an example of the use of the CallingConvention enumeration, see the DllImportAttribute class overview.]
Example
using System;
using System.Runtime.InteropServices;
/// <summary>
/// Sample demonstrating the use of the CallingConvention enumeration.
/// Use this enumeration to specify the calling convention for methods
/// decorated with DllImportAttribute.
/// </summary>
internal class CallingConventionSample
{
private static void Main()
{
WritePunctuationResultForChar(',');
WritePunctuationResultForChar('.');
WritePunctuationResultForChar('!');
WritePunctuationResultForChar('?');
WritePunctuationResultForChar('a');
WritePunctuationResultForChar('2');
Console.WriteLine();
Console.WriteLine();
Console.WriteLine("Press Enter to continue");
Console.ReadLine();
}
private static void WritePunctuationResultForChar(char c)
{
// iswpunct returns non-zero if c is a recognized punctuation character.
if (iswpunct(c) != 0)
{
Console.WriteLine("'{0}' is a punctuation character.", c);
}
else
{
Console.WriteLine("'{0}' is not a punctuation character.", c);
}
}
// C runtime method to determine if a given character represents a
// punctuation character. This is used purely to demonstrate calling a
// cdecl method; .NET code should use char.IsPunctuation(char).
[DllImport(
"msvcrt.dll",
CallingConvention=CallingConvention.Cdecl,
CharSet=CharSet.Unicode)]
private static extern int iswpunct(char c);
}
The output is
',' is a punctuation character.
'.' is a punctuation character.
'!' is a punctuation character.
'?' is a punctuation character.
'a' is not a punctuation character.
'2' is not a punctuation character.
Press Enter to continue
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