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That doesn't come from that. For example, I use another function which is defined in my Dll. Here is the Code:
typedef BOOL (CALLBACK* USB_ReadFile)(PVOID,DWORD,LPDWORD,ULONG);
USB_ReadFile pUSB_ReadFile;
char chBuffer[66000];
PVOID *lpBuffer = 0;
DWORD nNumberOfBytesToRead = 65536;
LPDWORD lpNumberOfBytesRead = 0;
ULONG Timeout = 5000;
hDLL = LoadLibrary("XtlUsb.dll");
if (hDLL != NULL)
{
pUSB_ReadFile = (USB_ReadFile)GetProcAddress(hDLL,"USB_ReadFile");
if (!pUSB_ReadFile)
{
FreeLibrary(hDLL);
}
else
{
BOOL BResult = TRUE;
BResult = pUSB_ReadFile(chBuffer,nNumberOfBytesToRead,lpNumberOfBytesRead,Timeout);
}
}
and here is the help given in MSDN:
typedef UINT (CALLBACK* LPFNDLLFUNC1)(DWORD,UINT);
.
.
.
HINSTANCE hDLL; // Handle to DLL
LPFNDLLFUNC1 lpfnDllFunc1; // Function pointer
DWORD dwParam1;
UINT uParam2, uReturnVal;
hDLL = LoadLibrary("MyDLL");
if (hDLL != NULL)
{
lpfnDllFunc1 = (LPFNDLLFUNC1)GetProcAddress(hDLL,
"DLLFunc1");
if (!lpfnDllFunc1)
{
// handle the error
FreeLibrary(hDLL);
return SOME_ERROR_CODE;
}
else
{
// call the function
uReturnVal = lpfnDllFunc1(dwParam1, uParam2);
}
}
The fatal error I have comes from when I call the function with its pointer.
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If you're getting a fatal error (exception, I guess) you could try stepping into the function call with the debugger, and then setting a stop on all exceptions, particularly C0000005 (access violation), and C++ exception.
That might help you work out what's happening.
At a guess, I'd say you were using a USB library to perform I/O to some device. Does your process need particular privileges to do this, or does the device driver (HIDSYS?) take care of it all for you.
Steve S
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I have a question concerning the use of a function defined in a Dll file.
I don't know precisely how to call a function defined in a Dll file.
I follow what MSDN specified but it doesn't work for the functions which take arguments. Here is the syntax I use to call the function "USB_WriteFile" defined in my Dll "XtlUsb.dll":
typedef BOOL (CALLBACK* USB_WriteFile)(PVOID,DWORD,LPDWORD,ULONG);
HINSTANCE hDLL;
hDLL = LoadLibrary("XtlUsb.dll");
USB_WriteFile pUSB_WriteFile;
PVOID lpBuffer = 0;
DWORD nNumberOfBytesToWrite = 0;
LPDWORD lpNumberOfBytesWritten = 0;
ULONG Timeout = Timeout;
if (hDLL != NULL)
{
pUSB_WriteFile = (USB_WriteFile)GetProcAddress(hDLL,"USB_WriteFile");
if (!pUSB_WriteFile)
{
FreeLibrary(hDLL);
return FALSE;
}
else
{
BOOL BResult = TRUE;
BResult = pUSB_WriteFile(lpBuffer,nNumberOfBytesToWrite,lpNumberOfBytesWritten,Timeout);
}
}
I have a fatal error coming from Visual C++ when arriving at the line "BResult = pUSB_WriteFile(lpBuffer,nNumberOfBytesToWrite,lpNumberOfBytesWritten,Timeout);"
Do you have any explanations?
Thank's for advance.
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could this Jeab. wrote:
I have a fatal error be a little more precise?
Don't try it, just do it! 
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Fatal error is now OK. The function must be defined like this:
typedef BOOL (__cdecl *USB_ReadFile) (PVOID,DWORD,LPDWORD,ULONG);
PVOID lpBuffer;
DWORD nNumberOfBytesToRead = 65536;
LPDWORD lpNumberOfBytesRead = 0;
ULONG Timeout = 5000;
USB_ReadFile pUSB_ReadFile;
hDll = LoadLibrary("XtlUsb.dll");
if (hDll != NULL)
{
pUSB_ReadFile = (USB_ReadFile)GetProcAddress(hDll,"USB_ReadFile");
if (!pUSB_ReadFile)
{
FreeLibrary(hDll);
return FALSE;
}
else
{
BOOL BResult = TRUE;
BResult = pUSB_ReadFile(lpBuffer,nNumberOfBytesToRead,lpNumberOfBytesRead,Timeout);
}
}
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below ,it is a part of program.
BOOL CAboutDlg::OnInitDialog()
{
CDialog::OnInitDialog();
VERIFY(m_editCopy.AutoLoad(IDC_button, this));
TRACE("HELLO");
return TRUE;
}
i insert two bitmaps ,at the same time ,i insert a button whose id is "IDC_BUTTON" and name "copy" .the two bitmap's id are "COPYU" and "COPYD".
I want to connect the copy button withe the two bitmaps by the function of "AutoLoad()",but when i run it,nothing error ,but why can not i get the
expected result?
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I try to find where is error and make small test program like your but it is working well. You must check your code and I do not know did you write resource simbol IDC_BUTTON or "IDC_BUTTON". Second is wrong in your case.
Regards,
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I'm looking for a hash table that maps strings to strings. I want to use this in a hooking procedure. The classical mfc classes don't work because pointers are a big nono for global hooking (dll mapped at different addresses for different processes). I tried and it sometimes works but most of the time not.
Basically I need a hooking class that uses static allocated tables. It should also know to manage memory itself (no malloc or free allowed) internally. Anyone know of such a class before I reinvent the wheel ?
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Hi...
It's my first time using vectors and I'm having problem using the 'begin' method. I did as follows...
vector ** a = new vector *[size];
...
vector<int>::iterator iter = a[u][v].begin();
a[u][v].insert(iter,lab);
...
I get unhandled exception error upon reading the iterator statement.
Pls help me allocate a value at the beginning of the 2d array...
Thank you.
Rgrds.
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Here is a class that shows how you can make a std::vector of std::vectors. It is heretic from the pure techings of the OOP-priests in that it inherits from a class (std::vector) that has no virtual destructor. Lint is crying in horror and I had to insert a switch.
But it works for me all the time. Also, a earlier version of a book by Alexandrescu also showed something like this.
/* matrix as vector of vectors*/
template<class T>
class Matrix : public std::vector<std::vector<T> > //lint -save -e1509
{
protected:
size_type rows,
columns;
public:
explicit Matrix(size_type r = 0, size_type c = 0)
: std::vector<std::vector<T> >(r, std::vector<T>(c)),
rows(r), columns(c)
{}
/* Thus, the Matrix class inherits from the std::vector class,
with the data type of the vector elements now being described
by a std::vector<T> template. With this, the matrix is a
nested container that exploits the combination of templates
with inheritance. The constructor initializes the implicit
subobject of the base class type (std::vector<std::vector<T> >)
with the correct size x. Exactly as with the standard vector
container, the second parameter of the constructor specifies
with which value each vector element is to be initialized.
Here, the value is nothing else but a vector of type
std::vector<T> and length y.*/
size_type Rows() const {return rows; }
size_type Columns() const {return columns; }
void init(const T& Value)
{
for (size_type i = 0; i < rows; ++i)
for (size_type j = 0; j < columns; ++j)
operator[](i)[j] = Value; // i.e. (*this)[i][j]
}
/* The index operator operator[]() is inherited from
std::vector. Applied to i, it supplies a reference to the ith
element of the (base class subobject) vector. This element is
itself a vector of type std::vector<T>. It is again applied
to the index operator, this time with the value j, which
returns a reference to an object of type T, which is then
assigned the value. */
// here, mathematical operators could follow ...
}; // class Matrix
//lint -restore
<hr size=1 /hr><small>"We trained hard, but it seemed that every time we were beginning to form up into teams we would be reorganised. I was to learn later in life that we tend to meet any new situation by reorganising: and a wonderful method it can be for creating the illusion of progress, while producing confusion, inefficiency and demoralisation."
-- Caius Petronius, Roman Consul, 66 A.D.</small>
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<i>template<class T>
class Matrix : public std::vector<std::vector<T>> /* ... */ </i>
Not able to compile the code with Visual C++ .NET 2002.
<b>Maxwell Chen</b>
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[Edited to show the templates corrcetly]
This, copied into a Win32-console-project, compiles with VC2003. Also, I know that VC6 is able to compile the class and produce running code from it.
Hope this helps!
------------------------------------------
#include "stdafx.h"
#include <vector>
/* matrix as vector of vectors*/
template<class T>
class Matrix : public std::vector<std::vector<T> > //lint -save -e1509
{
protected:
size_type rows,
columns;
public:
explicit Matrix(size_type r = 0, size_type c = 0)
: std::vector<std::vector<T> >(r, std::vector<T>(c)),
rows(r), columns(c)
{}
/* Thus, the Matrix class inherits from the std::vector class,
with the data type of the vector elements now being described
by a std::vector<T> template. With this, the matrix is a
nested container that exploits the combination of templates
with inheritance. The constructor initializes the implicit
subobject of the base class type (std::vector<std::vector<T> >)
with the correct size x. Exactly as with the standard vector
container, the second parameter of the constructor specifies
with which value each vector element is to be initialized.
Here, the value is nothing else but a vector of type
std::vector<T> and length y.*/
size_type Rows() const {return rows; }
size_type Columns() const {return columns; }
void init(const T& Value)
{
for (size_type i = 0; i < rows; ++i)
for (size_type j = 0; j < columns; ++j)
operator[](i)[j] = Value; // i.e. (*this)[i][j]
}
/* The index operator operator[]() is inherited from
std::vector. Applied to i, it supplies a reference to the ith
element of the (base class subobject) vector. This element is
itself a vector of type std::vector<T>. It is again applied
to the index operator, this time with the value j, which
returns a reference to an object of type T, which is then
assigned the value. */
// here, mathematical operators could follow ...
}; // class Matrix
//lint -restore
int _tmain(int argc, _TCHAR* argv[])
{
Matrix<double> ma(12, 12);
ma.init( 12.0);
return 0;
}
re beginning to form up into teams we would be reorganised. I was to learn later in life that we tend to meet any new situation by reorganising: and a wonderful method it can be for creating the illusion of progress, while producing confusion, inefficiency and demoralisation."
-- Caius Petronius, Roman Consul, 66 A.D.</small>
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Finally I found where the problem is. (Still with VC++ .NET 2002.)
1) If I write the code this way, it definitely does not compile:
class Matrix : public std::vector<std::vector<T>>
2) If this way, it compiles very well (note the space):
class Matrix : public std::vector<std::vector<T> >
Maxwell Chen
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Yes. Poor compiler: It thought you had asked for the shift-right operator.
One of these errors I always tend to overlook.
"We trained hard, but it seemed that every time we were beginning to form up into teams we would be reorganised. I was to learn later in life that we tend to meet any new situation by reorganising: and a wonderful method it can be for creating the illusion of progress, while producing confusion, inefficiency and demoralisation."
-- Caius Petronius, Roman Consul, 66 A.D.
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You have successfully created an array of pointers to vectors, but not the vectors being pointed at:
vector **a = new vector*[size];
for (int index = 0 ; index < size ; index++)
{
a[index] = new vector;
}
...
don't forget to delete them properly when you have finished with them.
for (index = 0 ; index < size ; index++)
{
delete a[index];
}
delete []a;
Roger Allen - Sonork 100.10016
<small><b>Strong Sad:
</b><i>Clever I am? Next to no one.
Undiscovered and soggy.
Look up. Look down. They're around.
Probably laughing. Still, bright, watery.
Listed among the top. Ten.
Nine. Late night. Early morn.
Early mourn. Now I sleep. </i></small>
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(in visual studio .net)
I'm a programmer mostly coming from the academic end of things (UNIX, gcc, etc.) and for the life of me cannot get variable types/functions from this dll. It's a development package for eeg analysis software that's supposed to allow me to read their specialized file format in c++ programs. Here's the link to the development kit:
http://www.axon.com/pub/utility/axonfsp/windows/
and I'm interested in using the axabffio32.dll functions and what (esp. things like ABF_ReadOpen and Abffileheader).
I've tried linking in the dir of the dll, copying the dll to the project dir, setting everything to release and adding the dll as a resource (as well as the #include of the dll)...what am I doing wrong???
here's the code:
void main( int argc, char **argv )
{
ABFFileHeader FH;
ABF_Initialize();
ABFH_Initialize(&FH);
Acquisition( argv[1], &FH );
ABF_Cleanup();
}
and here's the error I most often get:
c:\Documents and Settings\administrator\My Documents\Visual Studio Projects\abfDLL\abfDLL.cpp(16) : error C2065: 'ABFFileHeader' : undeclared identifier
c:\Documents and Settings\administrator\My Documents\Visual Studio Projects\abfDLL\abfDLL.cpp(16) : error C2146: syntax error : missing ';' before identifier 'FH'
c:\Documents and Settings\administrator\My Documents\Visual Studio Projects\abfDLL\abfDLL.cpp(16) : error C2065: 'FH' : undeclared identifier
c:\Documents and Settings\administrator\My Documents\Visual Studio Projects\abfDLL\abfDLL.cpp(18) : error C3861: 'ABF_Initialize': identifier not found, even with argument-dependent lookup
c:\Documents and Settings\administrator\My Documents\Visual Studio Projects\abfDLL\abfDLL.cpp(19) : error C3861: 'ABFH_Initialize': identifier not found, even with argument-dependent lookup
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You need to search for the identifier ABFFileHeader in the eeg include files and then #include it. Those errors do not relate to dlls in any way. Then once you have done that
just link to the corresponding .lib for the header file.
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ummmm....
well, this, perhaps?
// HEADER: ABFHEADR.H.
// PURPOSE: Defines the ABFFileHeader structure, and provides prototypes for
// functions implemented in ABFHEADR.CPP for reading and writing
// ABFFileHeader's.
tried compiling with #include "ABFHEADR.H" and here's the error I get now...
Compiling...
abfDLL.cpp
c:\Documents and Settings\administrator\My Documents\Visual Studio Projects\abfDLL\ABFHEADR.H(961) : error C2501: 'STATIC_ASSERT' : missing storage-class or type specifiers
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It might be due to some other include files, that are missing. I dont think there is any declaration like "STATIC_ASSERT" in mfc or win32, so it must be from some other 3rd party library.
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How are you trying to compile this?
I just did it and it worked for me.
I think that STATIC_ASSERT thing is erroneous I greped the src for it and could not find it anywhere.
ANyway I put it axon* in c:\test then just open all the
C:\test\AxonDev\Comp\Ax* and compile them.
THe paths need to be adjusted like I had to prepend 'c:\test' to everything and change
the post link setup for the .lib but thats it.
Regards,
Axe
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Hi
Iam using a structure called "QandA" in my application.I want to store the contents of that structure in a file in a specific format like...
Q1.
Ans1.xyz1
Ans2.xyz2
Q2.
Ans1.abc
Ans2.abc1
.....and so on
Q1,Ans1,Ans2,Q2...etc are the CString member variables.
How can i do this.Iam using a form based application.
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The best way is to replace QandA structure with QandA class. After that, you should write serialization method for your class.
The another way (which I prefer) is using XML file for storing structured data. It is more complex but it is very powerful.
Sincerely Yours,
RadioShark
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RadioShark wrote:
The best way is to replace QandA structure with QandA class
You can write functions for a struct just as well: A class differs from a struct only in the fact that all class members are private by default whereas all struct members are publich by default (but private: and public: work in both!).
"We trained hard, but it seemed that every time we were beginning to form up into teams we would be reorganised. I was to learn later in life that we tend to meet any new situation by reorganising: and a wonderful method it can be for creating the illusion of progress, while producing confusion, inefficiency and demoralisation."
-- Caius Petronius, Roman Consul, 66 A.D.
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I would urge you to write your own class serialisation, preferably into XML. In anything not entirly trivial, you need some way of versioning, and XML makes this easier.
You can override the MFC-calls if you like, but you will most probably need to write anything beneath it from scratch. You can use quite a lot of articles on CP about XML and serialisation
"We trained hard, but it seemed that every time we were beginning to form up into teams we would be reorganised. I was to learn later in life that we tend to meet any new situation by reorganising: and a wonderful method it can be for creating the illusion of progress, while producing confusion, inefficiency and demoralisation."
-- Caius Petronius, Roman Consul, 66 A.D.
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I have a dialog based application that has a tree control on it and when clicked on any item in the tree another dialog is opened that has two tab pages. I wanted to change the behavious of the application so that is any argument is passed to the application, instead of the dialog with tree opens, the second dialog with tap pages should open. But when i try to call the CTabbedDialog.DoModal() and exception occurs. 
Any thoughts why this exception is occuring?
Tariq
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