以下範例示範如何定義並呼叫 MessageBox User32.dll中的函數,將簡單字串作為參數傳遞。 在範例中, DllImportAttribute.CharSet 欄位設為 , Auto 讓目標平台決定字元寬度與字串編組。
using namespace System::Runtime::InteropServices;
typedef void* HWND;
[DllImport("user32", CharSet=CharSet::Auto)]
extern "C" IntPtr MessageBox(HWND hWnd,
String* pText,
String* pCaption,
unsigned int uType);
void main()
{
String* pText = L"Hello World!";
String* pCaption = L"Platform Invoke Sample";
MessageBox(0, pText, pCaption, 0);
}
using System;
using System.Runtime.InteropServices;
public class Win32 {
[DllImport("user32.dll", CharSet=CharSet.Auto)]
public static extern IntPtr MessageBox(int hWnd, String text,
String caption, uint type);
}
public class HelloWorld {
public static void Main() {
Win32.MessageBox(0, "Hello World", "Platform Invoke Sample", 0);
}
}
Imports System.Runtime.InteropServices
Public Class Win32
Declare Auto Function MessageBox Lib "user32.dll" _
(ByVal hWnd As Integer, ByVal txt As String, _
ByVal caption As String, ByVal Typ As Integer) As IntPtr
End Class
Public Class HelloWorld
Public Shared Sub Main()
Win32.MessageBox(0, "Hello World", "Platform Invoke Sample", 0)
End Sub
End Class
如需其他範例,請參閱 使用平台調用封送資料。