/// <summary>
/// Write a message to the specified mailslot
/// </summary>
/// <param name="hMailslot">Handle to the mailslot</param>
/// <param name="lpszMessage">The message to be written to the slot</param>
static void WriteMailslot(NativeMethods.SafeMailslotHandle hMailslot, string message)
{
int cbMessageBytes = 0; // Message size in bytes
int cbBytesWritten = 0; // Number of bytes written to the slot
byte[] bMessage = Encoding.Unicode.GetBytes(message);
cbMessageBytes = bMessage.Length;
bool succeeded = NativeMethods.WriteFile(
hMailslot, // Handle to the mailslot
bMessage, // Message to be written
cbMessageBytes, // Number of bytes to write
out cbBytesWritten, // Number of bytes written
IntPtr.Zero // Not overlapped
);
if (!succeeded || cbMessageBytes != cbBytesWritten)
{
Console.WriteLine("WriteFile failed w/err 0x{0:X}",
Marshal.GetLastWin32Error());
}
else
{
Console.WriteLine("The message \"{0}\" is written to the slot",
message);
}
}
static void Main(string[] args)
{
NativeMethods.SafeMailslotHandle hMailslot = null;
try
{
// Try to open the mailslot with the write access.
hMailslot = NativeMethods.CreateFile(
MailslotName, // The name of the mailslot
NativeMethods.FileDesiredAccess.GENERIC_WRITE, // Write access
NativeMethods.FileShareMode.FILE_SHARE_READ, // Share mode
IntPtr.Zero, // Default security attributes
NativeMethods.FileCreationDisposition.OPEN_EXISTING, // Opens existing mailslot
0, // No other attributes set
IntPtr.Zero // No template file
);
if (hMailslot.IsInvalid)
{
throw new Win32Exception();
}
Console.WriteLine("The mailslot ({0}) is opened.", MailslotName);
// Write messages to the mailslot.
// Append '\0' at the end of each message considering the native C++
// Mailslot server (CppMailslotServer).
WriteMailslot(hMailslot, "Message 1 for mailslot\0");
WriteMailslot(hMailslot, "Message 2 for mailslot\0");
Thread.Sleep(3000); // Sleep for 3 seconds for the demo purpose
WriteMailslot(hMailslot, "Message 3 for mailslot\0");
}
catch (Win32Exception ex)
{
Console.WriteLine("The client throws the error: {0}", ex.Message);
}
finally
{
if (hMailslot != null)
{
hMailslot.Close();
hMailslot = null;
}
}
}
