写入 Mailslot

写入 mailslot 类似于写入标准磁盘文件。 以下代码使用 CreateFile、 WriteFile 和 CloseHandle 函数将短消息放入 mailslot。 邮件将广播到本地计算机上名为“sample_mailslot”的邮件图服务器。 代码在已创建 mailslot 服务器的情况下运行。

#include <windows.h>
#include <stdio.h>

LPCTSTR SlotName = TEXT("\\\\.\\mailslot\\sample_mailslot");

BOOL WriteSlot(HANDLE hSlot, LPCTSTR lpszMessage)
{
   BOOL fResult; 
   DWORD cbWritten; 
 
   fResult = WriteFile(hSlot, 
     lpszMessage, 
     (DWORD) (lstrlen(lpszMessage)+1)*sizeof(TCHAR),  
     &cbWritten, 
     (LPOVERLAPPED) NULL); 
 
   if (!fResult) 
   { 
      printf("WriteFile failed with %d.\n", GetLastError()); 
      return FALSE; 
   } 
 
   printf("Slot written to successfully.\n"); 

   return TRUE;
}

int main()
{ 
   HANDLE hFile; 

   hFile = CreateFile(SlotName, 
     GENERIC_WRITE, 
     FILE_SHARE_READ,
     (LPSECURITY_ATTRIBUTES) NULL, 
     OPEN_EXISTING, 
     FILE_ATTRIBUTE_NORMAL, 
     (HANDLE) NULL); 
 
   if (hFile == INVALID_HANDLE_VALUE) 
   { 
      printf("CreateFile failed with %d.\n", GetLastError()); 
      return FALSE; 
   } 
 
   WriteSlot(hFile, TEXT("Message one for mailslot."));
   WriteSlot(hFile, TEXT("Message two for mailslot."));

   Sleep(5000);

   WriteSlot(hFile, TEXT("Message three for mailslot."));
 
   CloseHandle(hFile); 
 
   return TRUE;
}

下面是使用 Mailslot 读取中显示的 mailslot 服务器运行此示例时显示的输出。

Slot written to successfully.
Slot written to successfully.
Slot written to successfully.