|
| |
Contents | Index
Example C Program (using DDEML)
The following is the text for DEMO.CPP, a Borland C++ 3.0 program that
illustrates sending Request, Execute and Poke DDE transactions to the SPC application.
It should compile without difficulty under C++ 2.0 and will need minimal
rework to compile as a C program under Microsoft C 6.0, etc.
#include <windows.h>
#include <ddeml.h>
BOOL NEAR Execute (HCONV,LPSTR);
BOOL NEAR Request (HCONV,LPSTR,HDDEDATA* =NULL);
BOOL NEAR Poke (HCONV,LPSTR,LPSTR);
DWORD idDDE;
- oid FAR cdecl dm (LPSTR,...);
HDDEDATA EXPENTRY DdeCallback (WORD,WORD,HCONV,HSZ,HSZ,HDDEDATA,DWORD,DWORD);
#define EXEPATH "c:\\u\\spcwin\\spcwin.exe"
#pragma argsused
int PASCAL WinMain (HANDLE hInstance, HANDLE hPrevInstance,
LPSTR lpszCmdLine, int nCmdShow)
{
/* Initialize DDEML:
*/
FARPROC lpfn = MakeProcInstance((FARPROC)DdeCallback,hInstance);
if (DdeInitialize(&idDDE,
(PFNCALLBACK)lpfn,
APPCMD_FILTERINITS, NULL))
{
FreeProcInstance(lpfn);
return 1;
}
/* Create strings:
*/
HSZ hszService = DdeCreateStringHandle(idDDE,"SPCWin",NULL);
HSZ hszTopic = DdeCreateStringHandle(idDDE,"System",NULL);
/* Connect to system topic:
*/
HCONV hConv = DdeConnect(idDDE,hszService,hszTopic,NULL);
if (!hConv)
{
/* No connection - try running program and trying again:
*/
WinExec(EXEPATH,SW_SHOWNORMAL);
hConv = DdeConnect(idDDE,hszService,hszTopic,NULL);
}
if (hConv)
{
/* Connection made to system topic.
*/
dm("");
HDDEDATA hData;
/* Try to create data set using NEW.LIST command:
*/
if (Request(hConv,
"[NEW.LIST(3,25,DATE,D,,,N,COUNT,N,8,0,Y)]",&hData))
{
/* Query sample size (it should be 25.0 as set above):
*/
LPSTR lpsz = (LPSTR)DdeAccessData(hData,NULL);
char sz[201];
wsprintf(sz,"[SET.S.SIZE(\"%s\")]",lpsz);
Request(hConv,sz);
DdeUnaccessData(hData);
DdeFreeDataHandle(hData);
}
/* Disconnect from System topic:
*/
DdeDisconnect(hConv);
}
DdeFreeStringHandle(idDDE,hszTopic);
/* Attempt to connect to existing data set:
*/
hszTopic = DdeCreateStringHandle(idDDE,
"c:\\u\\spcwin\\data\\forddata.dbf",NULL);
hConv = DdeConnect(idDDE,hszService,hszTopic,NULL);
if (hConv)
{
/* Create X-bar and R chart on the " HEIGHT" column:
*/
Execute(hConv,"[NEW.CHART(0,,,\" HEIGHT\")]");
/* Tile windows:
*/
Execute(hConv,"[TILE]");
/* Change a cell's value:
*/
Poke(hConv,"R6C3","20.35");
/* Disconnect from data set topic:
*/
DdeDisconnect(hConv);
}
DdeFreeStringHandle(idDDE,hszTopic);
/* Free strings and deinitialize DDEML:
*/
DdeFreeStringHandle(idDDE,hszService);
DdeUninitialize(idDDE);
FreeProcInstance(lpfn);
return 0;
}
/* Send a Request transaction and print result to debug terminal:
* If phData is passed, return data handle to caller. Otherwise,
* free it.
*/
BOOL NEAR Request (HCONV hConv, LPSTR lpsz, HDDEDATA *phData)
{
HSZ hsz = DdeCreateStringHandle(idDDE,lpsz,NULL);
DWORD dw;
HDDEDATA hData = DdeClientTransaction(NULL,0L,hConv,
hsz,CF_TEXT,
XTYP_REQUEST,1000,&dw);
DdeFreeStringHandle(idDDE,hsz);
if (phData)
*phData = hData;
if (hData)
{
LPSTR lpszR = (LPSTR)DdeAccessData(hData,NULL);
dm("%s - %s",lpsz,lpszR);
DdeUnaccessData(hData);
if (!phData)
DdeFreeDataHandle(hData);
}
else
dm("Request %s - no response",lpsz);
return (hData != NULL);
}
/* Send an Execute transaction.
*/
BOOL NEAR Execute (HCONV hConv, LPSTR lpsz)
{
return (DdeClientTransaction((LPBYTE)lpsz,lstrlen(lpsz)+1,hConv,
NULL,CF_TEXT,
XTYP_EXECUTE,1000,NULL) != 0);
}
/* Send an Poke transaction.
*/
BOOL NEAR Poke (HCONV hConv, LPSTR lpszItem, LPSTR lpszData)
{
HSZ hsz = DdeCreateStringHandle(idDDE,lpszItem,NULL);
BOOL b = (DdeClientTransaction((LPBYTE)lpszData,lstrlen(lpszData)+1,hConv,
hsz,CF_TEXT,
XTYP_POKE,1000,NULL) != 0);
DdeFreeStringHandle(idDDE,hsz);
return b;
}
/* Output debug message.
*/
- oid FAR cdecl dm (LPSTR lpszFmt,...)
{
char sz[220];
wvsprintf(sz, lpszFmt, (LPSTR)(&lpszFmt + 1));
OutputDebugString(sz);
OutputDebugString("\n\r");
}
/* Callback need not do anything.
*/
#pragma argsused
HDDEDATA EXPENTRY DdeCallback (WORD wType,WORD wFmt,HCONV hConv,HSZ hsz1,
HSZ hsz2,HDDEDATA hData,DWORD lData1,
DWORD lData2)
{
return 0;
}
The MAKEFILE is as follows:
APP = demo
OBJ = $(APP).obj
CL = bcc -WE -mm -c -v -I\usr\binclude
LINK = tlink /Tw -v /c /L\usr\blib c0wm $(OBJ),$(APP).exe,nul,import cwm
ddeml;
.cpp.obj:
$(CL) -zC$*_TEXT $*.cpp
$(APP).exe: $(OBJ)
$(LINK)
rc -t $(APP).exe
obj: $(OBJ)
$(APP).obj: $(APP).cpp
|
