Browse - Programming Tips - How do I send data from a Windows process to another?
Keywords: interprocess, IPC, two
Q. How do I send data from a Windows process to another?
A. If you just want to send 2 numbers do this:
// This is the class name you used in your InitApplication() routine
// of the receiver. Typically win32 apps have routine named
// InitApplication() that calls RegisterClass() with a class name
// and other stuff
static LPCSTR gszReceiverClass = "ReceiverClass"; // CHANGE THIS!!!!
// The Receiver needs to process this windows message
#define WM_TWO_NUMBERS_TO_RECEIVER (WM_APP+1)
BOOL SendReceiverNumbers(const WPARAM n1, const LPARAM n2)
if ((hwndRec = FindWindow(gszReceiverClass, NULL)) == NULL) return
return PostMessage(hwndRec, WM_TWO_NUMBERS_TO_RECEIVER, n1, n2);
If your numbers are small you can actually send 4 like this:
BOOL SendReceiver4Numbers(const WORD a, const WORD b, const WORD c, const WORD d)
return SendReceiverNumbers(MAKEWPARAM(a,b), MAKELPARAM(a,b));
// Use LOWORD() on the receiving side
A Win32 Receiver does this:
int n1 = wParam;
int n2 = lParam;
// Do stuff with n1 and n2
If you want to pass more look at