Monitoring Communications Events - Win32 Programmer's Reference

Custom Search

Monitoring Communications Events

The following example code opens the serial port for overlapped I/O, creates an event mask to monitor CTS and DSR signals, and then waits for an event to occur. The WaitCommEvent function should be executed as an overlapped operation so the other threads of the process cannot perform I/O operations during the wait.

HANDLE hCom;
OVERLAPPED o;
BOOL fSuccess;
DWORD dwEvtMask;

hCom = CreateFile("COM1",
GENERIC_READ | GENERIC_WRITE,
0, /* exclusive access */
NULL, /* no security attrs */
OPEN_EXISTING,
FILE_FLAG_OVERLAPPED,
NULL
);

if (hCom == INVALID_HANDLE_VALUE) {
/* Deal with the error. */
}

/* Set the event mask. */

fSuccess = SetCommMask(hCom, EV_CTS | EV_DSR);

if (!fSuccess) {
/* deal with error */
}

/* Create an event object for use in WaitCommEvent. */

o.hEvent = CreateEvent(NULL, /* no security attributes */
FALSE, /* auto reset event */
FALSE, /* not signaled */
NULL /* no name */
);

assert(o.hEvent);

if (WaitCommEvent(hCom, &dwEvtMask, &o)) {
if (dwEvtMask & EV_DSR) {
/*
* . . .
*/
}

if (dwEvtMask & EV_CTS) {
/*
* . . .
*/
}
}

Last news from Greatis Software

    Nostalgia .Net     .Net is powerful, but not all-powerful, so sometimes we need to use Win32 API for our .Net applications. It's simple enough with Platform Invoke if you have Win32 skill, but we do not always have time to dig the ancient documentation, declare the special types that are compatible with Win32, find the values of the Win32's constants and so on. Nostalgia .Net offers several simple-to-use classes, and components that will allow you to forget about the headache of Win32 and just use the power of Win32 in your application the same way as you use the native. Net classes. More »

Recommended software for developers

    Ultimate Pack     Component pack for Delphi and C++ Builder that contains runtime form designer, runtime object inspector, print suite and much more for the very special price. More »

    Form Designer .Net     Unique runtime form design solution that allows to edit any form in .Net WinForms application at runtime with full source codes for only 300 euro! More »

    Print Suite .Net     Print Suite .Net is a set of components for easy printing texts, images and grids from your WinForms applications. Full C# source codes are available More »

    Gradient Controls .Net     Gradient Controls .Net offers controls with gradient background feature. Labels, panels and so on... Full C# source codes are available More »

    Greatis iGrid     iGrid plots drawing grid right over your desktop, so you can use it everywhere, with any drawing application without any special plugins for different graphic editors. More »

All the contacts and projects

Dmitry Vasiliev (just.dmitry)

More Online Helps

Win32 Programmer's Reference
Win32 Multimedia Programmer's Reference
OLE Programmer's Reference
Microsoft Windows Pen API Programmer's Reference
Microsoft Windows Sockets 2 Reference
Microsoft Windows Telephony API (TAPI) Programmer's Reference
Unix Manual Pages

greatis just4fun network