Himself with vs wove a mscomm serial communication program, normal transceiver can receive text in the edit box and associated cstrings variables, I now ask mscomm1. Setoutput () after sending an instruction, the machine will automatically reply to a message (lower machine itself), receives the data and change the cstrings variables and then to deal with, now edit box to receive reply instruction, but cstrings value does not change,,,,
. In addition, I send out a mscomm1 setoutput (), a chance to automatically reply to a message, at this point is directly into OnCommMscomm1 () receiving callback function? Teach,,,,,,,,

CodePudding user response:

You can be in OnCommMscomm1 () to set breakpoints, see what value is returned

CodePudding user response:

 
Void CUseMsComm32OCXDlg: : OnMscomm () 
{
//TODO: Add your the control notification handler code here 
Cstrings strEvent strError; 
Cstrings STR. 
Short evt=m_MyMSComm. GetCommEvent (); 
The switch (evt) 
{//Events 
Case ComEvSend://There are SThreshold number of characters in the transmit buffer. 
StrEvent="Sending". 
break; 
Case ComEvReceive://Received RThreshold number of chars. 
{
//strEvent="identifiers"; 
The VARIANT var. 
Var=m_MyMSComm. GetInput (); 
//
If (m_MyMSComm GetInputMode ()==ComInputModeText) 
{//ComInputModeText 
STR=var. BstrVal; 
} 
The else 
{//ComInputModeBinary, over the Text. 
COleSafeArray arr. 
Arr=var; 
Long len=arr. GetOneDimSize (); 
BYTE Data [4096]. 
Data [len]=0;//sz 
For (long jj=0; Jj & lt; Len. Jj++) 
{
Arr. GetElement (& amp; Jj, & amp; Data [jj]); 
} 
//if true binary, we should convert the Data to the string 
Char * newStr=0; 
NewStr=(char *) KillHalfHZ (Data, len);//no sz! 
STR=Data; 
} 
ShowData (STR); 
break; 
} 
Case ComEvCTS://Change in the CTS line. 
//strEvent="CTS changed"; 
break; 
Case ComEvDSR://Change in the DSR line. 
The DSR strEvent="changed"; 
break; 
Case ComEvCD://Change in the CD line. 
//strEvent="CDC changed"; 
break; 
Case ComEvRing://Change in the Ring Indicator. 
StrEvent="Phone Ring"; 
break; 
Case ComEvEOF://An EOF charater was found in the input stream 
StrEvent="EOF detected"; 
break; 
//Errors 
Case ComEventBreak://A Break was received. 
The strError="Break Received"; 
break; 
Case: 1002//vbMSCommErCTSTO: 
The strError="CTS Timeout"; 
break; 
Case: 1003//vbMSCommErDSRTO: 
The strError="DSR Timeout"; 
break; 
Case ComEventFrame://Framing Error 
The strError="Framing Error"; 
break; 
Case ComEventOverrun://Data Lost. 
The strError="Overrun Error"; 
break; 
Case: 1007//vbMSCommErCDTO: 
The strError="CD TimeOut"; 
break; 
Case ComEventRxOver://the Receive buffer overflow. 
The strError="R buffer Overflow"; 
break; 
Case ComEventRxParity://Parity Error. 
The strError="Parity Error"; 
break; 
Case ComEventTxFull://the Transmit buffer full. 
The strError="T buf Full"; 
break; 
Case ComEventDCB://Unexpected error retrieving DCB 
The strError="DCB error"; 
break; 
} 
//
if (! StrEvent. IsEmpty ()) 
{
AfxMessageBox (strEvent); 
} 
if (! The strError. IsEmpty ()) 
{
AfxMessageBox (" ComError MB_ICONEXCLAMATION); 
M_MyMSComm. SetPortOpen (FALSE); 
} 
} 

.cpp
BEGIN_EVENTSINK_MAP (CUseMsComm32OCXDlg CDialog)
//{{AFX_EVENTSINK_MAP (CUseMsComm32OCXDlg)
OnComm ON_EVENT (CUseMsComm32OCXDlg IDC_MSCOMM1, 1/* */, OnMscomm, VTS_NONE)
//}} AFX_EVENTSINK_MAP
END_EVENTSINK_MAP ()
.h
Afx_msg void OnMscomm ();

 
Void CUseMsComm32OCXDlg: : ShowData (LPCTSTR pchData) 
{
Cstrings STR. 
Int nCharIndex; 
Int nBackcount=0; 

//Make sure existing text doesn 't get too large. 
Int len=m_Edit. GetWindowTextLength (); 
If (len & gt; 
=16384){
M_Edit. GetWindowText (STR); 
M_Edit. SetWindowText (STR. GetBuffer (len) + 4097); 
Len -=4097; 
} 
//Handle backspace characters. 
STR=pchData; 
While ((nCharIndex=STR. Find (TCHAR (VK_BACK)))!=1) 
{
If (nCharIndex==0) 
{
NBackcount++; 
STR=STR. Mid (nCharIndex + 1); 
} 
The else 
{
STR=STR. Left (nCharIndex - 1) + STR. The mids (nCharIndex + 1); 
} 
} 
//Set the text insertion point "according to the number of backspaces 
//at the begining of strData. 
If (nBackcount> Len) nBackcount=len; 
M_Edit. SetSel (len - nBackcount, len); 
//Eliminate line feeds. 
While ((nCharIndex=STR. Find (TCHAR (' \ n ')))!=1) 
{//delete all ah 0 
STR=STR. Left (nCharIndex) + STR. Mid (nCharIndex + 1); 
} 
//Ensure all carriage returns have a line feed following. 
LPCTSTR pchStart=(LPCTSTR STR); 
LPTSTR pchIndex=_tcschr (pchStart, (TCHAR) '\ r'); 

While (pchIndex!=NULL) 
{//add 
Int nPos=pchIndex - pchStart; 
STR=STR. Left (nPos + 1) + cstrings (' \ n ') + STR. Mid (nPos + 1); 
//Above operation probably allocated a new string buffer. 
PchStart=(LPCTSTR STR); 
PchIndex=_tcschr (nPos pchStart + + 1, (TCHAR) '\ r'); 
} 
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