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thanks a lot, please tell me , if I have a data buffer like "BYTE* p = myData;// there are many 0 values in buffer", I know buffer 's length, how to transfer the data use BSTR?
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Don't treat the BSTR as a null-terminated string!
Use SysAllocStringByteLen to allocate the space.
Cast the BSTR to BYTE* and use SysStringByteLen to get the byte count.
Free the string as normal with SysFreeString.
MSDN does say that a SAFEARRAY with element type VT_UI1 is preferred, in order that you don't get translations on 16/32-bit borders...but a) who uses 16-bit OLE now?, and b) BSTR is a lot easier in C++ 
Stuart Dootson
'Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p'
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It seems as if the method does not work. Following my code :
1:declare interface------
dispinterface _IMyEvents
{
properties:
methods:
[id(1), helpstring("method Test")] HRESULT Test([in]DWORD dwLen, [in] BSTR pData);
};
2:method implement-------
HRESULT Fire_Test(ULONG dwLen, BSTR pData)
{
CComVariant varResult;
T* pT = static_cast<t*>(this);
int nConnectionIndex;
CComVariant* pvars = new CComVariant[2];
int nConnections = m_vec.GetSize();
for (nConnectionIndex = 0; nConnectionIndex < nConnections; nConnectionIndex++)
{
pT->Lock();
CComPtr<iunknown> sp = m_vec.GetAt(nConnectionIndex);
pT->Unlock();
IDispatch* pDispatch = reinterpret_cast<idispatch*>(sp.p);
if (pDispatch != NULL)
{
VariantClear(&varResult);
pvars[1] = (int)dwLen;
pvars[0] = pData;
DISPPARAMS disp = { pvars, NULL, 2, 0 };
pDispatch->Invoke(0x2, IID_NULL, LOCALE_USER_DEFAULT, DISPATCH_METHOD, &disp, &varResult, NULL, NULL);
}
}
delete[] pvars;
return varResult.scode;
}
3:call method in Server Object------
{
char a[10] = _T("abcdef");
a[8] = 'x';
BSTR bstr = SysAllocStringByteLen(a, 10);
Fire_Test(10, bstr);
}
4:called in Client -------
long CEventNotifySink::OnTest(DWORD dwLen, BSTR pData)
{
UINT len = SysStringByteLen (pData); // result: len!=10
BYTE * p = (BYTE*)pData; // pData refs wrong address
SysFreeString(pData);
return 0;
}
where is wrong?
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The problem is CComVariant - that uses SysAllocString to copy the BSTR. The signature of SysAllocString is BSTR SysAllocString(const OLECHAR * sz); - it assumes that the input BSTR is null-terminated.
If you create your VARIANT manually, you shouldn't have a problem:
VARIANT v;
V_VT(v) = VT_BSTR;
V_BSTR(v) = pData;
Stuart Dootson
'Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p'
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not only length, the "pData" refer wrong address, data is wrong.
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Creating the CComVariant *copied* the BSTR - i.e. created a new one. It will therefore have a different address from the original.
Stuart Dootson
'Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p'
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I trace my my code and find that, in ATL,
COleDispatchImpl::Invoke(...) method calls CallMemberFunc(...),
and CallMemberFunc() method calls PushStackArgs(...),
there is such a sentence----"pArgTemp->bstrVal = AfxBSTR2ABSTR(pArg->bstrVal);" in PushStackArgs(...) method, After this call happened, my buffer data lost .
how to resolve the problem?
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Hmmmm - COleDispatchImpl is part of MFC, not ATL...
Anyway - I've built a sample COM object (with connection point) using ATL and a harness executable (built using ATL to implement the connection point interface). This passes a BSTR as the event parameter and it seems to work fine...
I've got this code to fire the event:
STDMETHODIMP CPooh::Trigger()
{
BSTR bs;
BYTE a[10] = { 0x0, 0x1, 0x2, 0x3, 0x4, 0x0, 0x1, 0x2, 0x3, 0x4 };
bs = ::SysAllocStringByteLen((const char*)a, 10);
Fire_Pooh(bs);
return S_OK;
}
and this code catching the event:
void __stdcall OnPooh(BSTR bs)
{
size_t s = ::SysStringByteLen(bs);
BYTE* data = (BYTE*)bs;
}
I'm getting s set to 10, and data containing the 10 bytes set in the Trigger method.
As I said - I'm using ATL code all the way and it works fine...
Stuart Dootson
'Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p'
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thank you, Stuart Dootson. I wrote client with MFC, there must be something wrong in my code. Later I wrote a new client with ATL, everything works fine. ![Rose | [Rose]](https://codeproject.freetls.fastly.net/script/Forums/Images/rose.gif)
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samfromcn wrote:
something wrong in my code
I'd bet that it's in the MFC code - that's why I use ATL for COM code 
Stuart Dootson
'Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p'
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Hi, is there an "easy" way to save the state of an object to a file without using MFC or COM objects?
im working on a WTL project that needs to save and read a special form of "document" to file, (kind of like MFC´s Serialize()), but even tho i have the code to do it in binary mode, i would prefer to do it on XML.
The documents are quite large, and consists of other objects containing several arrays of CStrings (WTL:CString that is), and primitives like ints, floats, etc.
Is there a Non-MFC, Non-COM related XML parser i could use?
thanks!
The only stupid question is that one wich is never asked
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I understand you not using MFC ( what XML parser uses MFC anyhow ? ), but why not COM ? Do you want to avoid a dependancy ? I'll admit that I was annoyed recently to find that my video jukebox program needs IE5 for MSXML because I used openXML in a single database query.
Christian
I have several lifelong friends that are New Yorkers but I have always gravitated toward the weirdo's. - Richard Stringer
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thanks for your answers, to be honest, i dont wanna include COM simply because i dont know how to use it (blushes). I dont know about interfaces and that stuff.
But lets say that the only thing off-limits would be MFC (COM is OK), which parser you guys reccomend?
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How about using a serialization library? Boost::Serialization supports text, binary and xml as output targets, and is pretty simple to use.
TinyXml Is a nice small library that has picked up a fair ammount of popularity.
Xerces To my way of thinking was pretty bloated, but if you need your output to support almost everything in the XML standard (especially different encoding schemes) this is the way to go.
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boost looks VERY interesting, i think ill go with it.
Thanks!
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Hi,
Office 2003 provides smart tag functionality to outlook if Word 2003 is the default email editor. Oulook uses InternetExplorer_Server
class window to show the messages composed using MS-Word or HTML
format and this window is capable of displaying smart tags. Messages
composed in Plain Text or Rich Edit are displayed in RichEdit20W
class window and this window cannot show smart tag information.
My problem is to provide smart tag kind of functionality to this
RichEdit20W class window. Is there any way to get the handle of
email viewer window of outlook?
One more behaviour I've observed that the smart tag information is
embeded into the message at the time of composing the message and
not at the time of viewing it. My requirement is to recognize smart
tags at the time of viewing the mails. I can choose any editor for
composing the message and any editor for viewing the message. I want
the smart tag functionality be available in every case.
Please help me if you have any idea in this regard.
- Rajeev
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I cannot get the data from my vector after I’ve loaded it! It shows in debug that the vector is loading, but I can’t get the data it has loaded out of the vector.
Also, how do I save/load the vector to file. No one explains the file operations for containers that I can find.
Here’s the pertinent code:
#pragma warning(disable: 4786)
#include "stdafx.h"
#include "Well.h"
#include "Leases.h"
//#include "stdafx.h"
//#include "stdafx.h"
using std::cout;
using std::endl;
int main(int argc, char* argv[])
{
cout << "Hello World" << endl << endl;
CLease cleases;
/*
int i = 0;
for(i=0; i<6; i++)
{
cout << nSerialNum << strUseMap << " " << strWellDescription << " " << strWellName << endl; endl;
db::it++;
}
*/
return 0;
}
/* This class will be included in the vector and then saved to the file
*/
#if !defined AFX_WELL_H__
#define AFX_WELL_H__
#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000
#include "stdafx.h"
#include <string>
//#include <vector>
//#include "Leases.h"
//#include <string>
using std::string;
class CWell {
public:
string& GetWellName2();
string& GetWellDescription2();
string& GetUseMap2();
long GetSerialNum2();
string GetWellName(string& str);
string GetWellDescription(string& str);
string GetUseMap(string& str);
long GetSerialNum(long& SN);
CWell();
virtual ~CWell();
void Initialize();
protected:
string strWellName;
string strWellDescription;
string strUseMap;
long nSerialNum;
// Fuctions of class
// string GetWellName();
// string GetWellDescription();
// string GetUseMapLocation();
// long GetSerialNumber();
};
#endif // !defined AFX_WELL_H__
#include "stdafx.h"
//#include <vector>
#include "Well.h"
//#include <string>
CWell::CWell() {
// This class holds the data for each well
strUseMap = "";
strWellDescription = "";
strWellName = "";
nSerialNum = 0;
}
CWell::~CWell() {
}
// end class
void CWell::Initialize()
{
// Initialize the well class members to 0/NULL
nSerialNum = 0;
strUseMap = "";
strWellDescription = "";
strWellName = "";
}
long CWell::GetSerialNum(long& SN)
{
return nSerialNum = SN;
}
string CWell::GetUseMap(string& str)
{
return strUseMap = str;
}
string CWell::GetWellDescription(string& str)
{
return strWellDescription = str;
}
string CWell::GetWellName(string& str)
{
return strWellName = str;
}
long CWell::GetSerialNum2()
{
return (long)nSerialNum;
}
string& CWell::GetUseMap2()
{
return strUseMap;
}
string& CWell::GetWellDescription2()
{
return strWellDescription;
}
string& CWell::GetWellName2()
{
return strWellName;
}
#if !defined AFX_LEASES_H__
#define AFX_LEASES_H__
#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000
#include "Well.h"
#include "stdafx.h"
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
//#include "Well.h"
using std::vector;
using std::iterator;
class CWell;
class CLease {
public:
CLease();
~CLease();
protected:
int nNumOfWells;
std::vector<cwell> db;
std::vector<cwell>::iterator it;
CWell cwells;
};
#endif // end class definition
#include "stdafx.h"
#include "Leases.h"
#include "stdlib.h"
using std::cout;
using std::endl;
CLease::CLease()
{
//CWell cwells = new CWell;
cwells.Initialize();
// For Testing Only : delete after testing is complete
long SN, SN2 = 0;
string str, str2, str3 = "";
int i = 0;
for(i=0; i< 6; i++)
{
switch(i)
{
case 0: SN = 0; SN2 = cwells.GetSerialNum(SN);
str = "1st Use Map"; cwells.GetUseMap(str); str = "";str2 = "";
str = "1st WellDescription"; cwells.GetWellDescription(str); str = "";str2 = "";
str = "1st Well Name"; cwells.GetWellName(str); str = "";str2 = "";
break;
case 1: SN = 1; SN2 = cwells.GetSerialNum(SN); SN = 0;
str = "2nd Use Map"; str2 = cwells.GetUseMap(str); str = "";str2 = "";
str = "2nd WellDescription"; str2 = cwells.GetWellDescription(str); str = "";str2 = "";
str = "2nd Well Name"; str2 = cwells.GetWellName(str); str = "";str2 = "";
break;
case 2: SN = 2; SN2 = cwells.GetSerialNum(SN); SN = 0;
str = "3rd Use Map"; str2 = cwells.GetUseMap(str); str = "";str2 = "";
str = "3rd WellDescription"; str2 = cwells.GetWellDescription(str); str = "";str2 = "";
str = "3rd Well Name"; str2 = cwells.GetWellName(str); str = "";str2 = "";
break;
case 3: SN = 3; SN2 = cwells.GetSerialNum(SN); SN = 0;
str = "4th Use Map"; str2 = cwells.GetUseMap(str); str = "";str2 = "";
str = "4th WellDescription"; str2 = cwells.GetWellDescription(str); str = "";str2 = "";
str = "4th Well Name"; str2 = cwells.GetWellName(str); str = "";str2 = "";
break;
case 4: SN = 4; SN2 = cwells.GetSerialNum(SN); SN = 0;
str = "5th Use Map"; str2 = cwells.GetUseMap(str); str = "";str2 = "";
str = "5th WellDescription"; str2 = cwells.GetWellDescription(str); str = "";str2 = "";
str = "5th Well Name"; str2 = cwells.GetWellName(str); str = "";str2 = "";
break;
case 5: SN = 5; SN2 = cwells.GetSerialNum(SN); SN = 0;
str = "6th Use Map"; str2 = cwells.GetUseMap(str); str = "";str2 = "";
str = "6th WellDescription"; str2 = cwells.GetWellDescription(str); str = "";str2 = "";
str = "6th Well Name"; str2 = cwells.GetWellName(str); str = "";str2 = "";
break;
} // end switch
db.push_back(cwells);
SN = 0;
str = "";
str2 = "";
str3 = "";
} // end for
// now check the container
CWell well;
for(it=db.begin(); it != db.end(); it++)
{
SN = cwells.GetSerialNum2();
str = cwells.GetUseMap2();
str2 = cwelsl.GetWellDescription2();
str3 = cwells.GetWellName2();
cout << SN << " " << str << " " << str2 << " " << str3 << endl;
//cout << *it << endl;
SN = 0;
str = "";
str2 = "";
str3 = "";
} // end for
}
CLease::~CLease()
{
}
C++ is my favorite programming language
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I develope a DLL that is loaded with every instance of Internet Explorer. In the DLL, I want to handle something like "BeforeNavigate" event to get the URL user enter in the Adress Bar.
I've written this DLL before in C#. And in C#, handle this event is quite easy, just write something like:
WebBrowser browser;
browser.BeforeNavigate2 += new DWebBrowserEvents2_BeforeNavigate2EventHandle(this.BeforeNavigate);
But now, I have to write it in Visual C++ 6.0. How can I handle this event in Visual C++ 6.0?
Hope to see your replies soon.
Thanks.
Lan hue sau ai lan hue heo
Lan hue sau doi trong heo ngoai tuoi
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hi!
i have tried to store bitmap image into my activex control. i used the following Put property to store image.
[propput, id(7), helpstring("property CompanyLogo")] HRESULT CompanyLogo([in] IPictureDisp * newVal);
and in it i wrote following four lines of code.
m_pCompLogoDisp = newVal;
SetDirty(true);
SendOnDataChange();
FireViewChange();
The property is receiving image data but not persisting it.
does my property declarion incorrect. if so then plz help me.
Thanks in advance.
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I've a MTS/COM+ component (COMPONENT_1) that #imports ADO library. And, I have another MTS/COM+ component (COMPONENT_2) that #imports this component. I need to use ADO objects in my second component (COMPONENT_2) too. If I use #import in my second component, I get lots of errors. If I do not, the MIDL compiler remains unable to recognize _Recordset data type. Can anyone please show me how to do it?
I am using ATL with Visual C++ 6.0 SP5.
Thanks
Gurmeet
BTW, can Google help me search my lost pajamas?
My Articles: HTML Reader C++ Class Library, Numeric Edit Control
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Hi-- I've been banging my head trying to solve this problem. Of course I'm a self trained pseudo programmer who just started to use STL. I have a huge file with 10 million entries that are paired, say:
1 8
1 5
1 3
2 0
2 4
3 0
3 8
etc...
They are stored as a two dimensional array of 10 million rows and two columns... you get the idea of the data. I need to find the records in the file that have one and only one of the tags in the first entry of the pair and put the second in another vector file in the order found. For example, if I need records with the tag 2, I'll create the vector
0
4
I suppose I need to use a multimap, but do not know how to read the file and then store the results in a vector. Right now I have this simple code:
typedef vector DVECTOR;
DVECTOR FDV;
int tag;
double FD;
int id = 3;
int idp = id + 1;
while(tag != idp)
{
GetData >> tag >> FD;
cout << tag << " " << FD << endl ;
if(tag == id)
FDV.push_back(FD);
}
This does what I want by scaning the file from the begining until it finds the target value and reads all the entries with such value. If the number is close to the first entry, cool it's fast, but if it is near the end it will take a long time (big program repeated many times...). The question is, would the multimap work better and faster to do the same task? If so... how do I do it??? that is, read the file, store the data in a multimap, search for the tag number of my interest and copy all values associated to the tag number into a vector. If I have to read the whole 10 million line file to put it in a map, then it's going to be hanging around in memory for further use (several times)... or should I read the file every time I need it?? If so, then, isn't my naive code more efficient???
By the way, I'm trying this other code using multimap but gives me horrible error messages:
typedef multimap<int, double=""> DMMAP;
DMMAP mapfish;
while(!GetData.eof())
{
GetData >> tag >> FDS;
mapfish.insert(make_pair(tag,FDS));
}
argggggggggggggggggggggggggg 
Thank you so much!
Carlos
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Well, if I understand your scenario correctly, you have two valid alternatives:- Scan the whole file into a
multimap and use this later several times. - Improve your file searching by doing something like a binary search on it. This is a little complex, but doable: broadly sketched, you have to open the file and set the current offset to the middle of it, skip characters until you find a newline and then read the entry: if the tag is
id-1, keep on reading till you get to your target portion and proceed. If the tag is greater than that, set the offset to 1/4 of the file, else set it to 3/4, proceed recursively etc.
If you'll be doing the search many times, the multimap solution is probably faster, otherwise you'll have better performance with binary searching on the file. We can do an estimate: Let us call N the number of entries (10 millions in your case) and S the number of search operations you're going to perform on the file. Each search takes approximately log2N entry readings, so the binary search method will read in total S*log2N file entries. With the first method, the entries read are exactly N, as you scan the entire file. So the first method is better (on a first approximation) than the second if
N < S*log2N
With 10 million entries, this means the first method wins if you do more than ~430,000 search operations. I guess you won't do that many searches, hence my hunch is that you're probably better off implementing the file binary search stuff. Hope this helps a little.
Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo
Want a Boost forum in Code Project? Vote here[^]!
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