I have a third-party Windows app that supports a C plugin/driver (see spec below) to be a passive data receiver once initialized. Now I found a C# package that does the data gathering and Pushing. The only missing piece here is a bridge between the C dll and the C# dll.
The data flow is like this: When the app is launched, it loads and calls the C dll which contains several exported functions including an init function. In this init function, I like to establish a call to the C# to setup some network connection and prepare for incoming data. Once that done, according to the driver spec, the C# dll will gather data and stream it to the receiving driver. To accommodate this, I have two thoughts (you may come up with more):
1) to wrap the C# with C++/Cli and call the expose C#-like methods from the driver. Declare an object with gcroot, then instantiate it with gcnew then call the method(s). Tried that and I got stackoverflowexception. I am new to this mix-mode programming and can't figure out why that happened.
2) to wrap the C dll in some way (like using C++/Cli to import the C functions then interact with the C# data streamer) to be callable from C#. What is the best way to do this?
I have done some reading and it seems C++/Cli is the easy route but I am open to other not so complicated options as well. What are the project settings I have to add/modify to make it work should I choose C++/Cli or any way you suggest?
As I am new to tackle this kind of problem, any samples or related links are helpful. So I appreciate if you could demonstrate how things work one way or the other.
Here is piece of the skeletal C# dll referenced (other methods are omitted):
public class Client {
public Client()
{
//reset();
}
public void test()
{
Console.WriteLine("test");
}
/// <summary>
/// Connect connects the Client to the server.
/// Address string has the form host:port.
/// </summary>
public void Connect(string address)
{
Disconnect();
// validate address
int sep = address.IndexOf(':');
if (sep < 0)
{
throw new ArgumentException("Invalid network address");
}
// set host and port
host = address.Substring(0, sep);
toPort(ref port, address.Substring(sep + 1));
// connect
Socket socket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
socket.Connect(host, port);
rw.Set(socket, CLIENT_DEFAULT_BUFFER_SIZE);
}
/// <summary>
/// Disconnect disconnects the Client from the server.
/// </summary>
public void Disconnect()
{
backlog.Clear();
try
{
if (Connected)
{
write("close");
}
}
catch (Exception e)
{
}
//reset();
//rw.Close();
}
}
Here is the skeletal spec of the C dll:
//APIs
#ifdef __cplusplus
extern "C"{
#endif
#define DLL __declspec(dllexport)
////////////////////////////////////////////////////////////////////////////
// Initialization: do some prep for receiving data from C#
// params:
// hWnd handle
// Msg message
// nWorkMode work mode
// return:
// 1 true
// -1 false
DLL int Init(HWND hWnd, UINT Msg, int nWorkMode);
// Quitting and closing
// Param:
// hWnd same handle as Init
// return:
// 1 true
// -1 fals
DLL int Quit(HWND hWnd);
#ifdef __cplusplus
}
#endif
