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Use std::ifstream to open the file and then use ifstream::read method to read bytes from the file.
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Arman
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Is it more urgent then this question? The double posting let me assume so, generally it's better to ask a specific programming question... instead of asking others to do your homework or find a solution for a work assignment. 
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I don't want to do my homework, I am a beginer and I have problem reading a file byte by byte  I just ask for some help
thnx for advise
neda
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Reading a file byte by byte as absolutely nothing to do with drawing an histogram. So, your question is totally unclear.
A previous post already answered how to read the file.
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ndadashi wrote: I don't want to do my homework, I am a beginer and I have problem reading a file byte by byte I just ask for some help
Oh please be frank, you have asked for a complete solution not how to read a simple file... here what I would suggest: Brake down your problem and try to ask specific technical questions if you get stuck. Let's look at your task:
1) open file and read it into memory
2) analyse image file format and e.g. decompress it to raw RGB data (e.g. use a library that provides that)
3) use histogram algorithm (very likely out of scope for this forum)
4) create a user interface that can output your data. If you want a graph of the historgram you should browse for custom controls here at CodeProject or alternatively write your own owner-draw control to do that.
5) extend your user interface to modify the histogram.... and further functionality you may want add to your application.
With each subtask it may be possible to help, now go get coding!! 
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Hi !
In my application when i debug it. it gives me the the following result in the call stack.
> msvcr80d.dll!strlen(unsigned char * buf=0x0235b848) Line 81 Asm //crashed here msvcp80d.dll!std::char_traits<char>::length(const char * _First=0x00000000) Line 559 + 0x9 bytes C++
msvcp80d.dll!std::basic_string<char,std::char_traits<char>,std::allocator<char> >::assign(const char * _Ptr=0x00000000) Line 1042 + 0x9 bytes C++
msvcp80d.dll!std::basic_string<char,std::char_traits<char>,std::allocator<char> >::basic_string<char,std::char_traits<char>,std::allocator<char> >(const char * _Ptr=0x00000000) Line 644 C++
DRMClient.exe!openutils::WebForm::putVariable(const char * var_name=0x0047f694, const char * value=0x00000000) Line 142 + 0x12 bytes C++
DRMClient.exe!Package::GenerateConfigurePackageRequest(std::basic_string<char,std::char_traits<char>,std::allocator<char> > uid="", std::basic_string<char,std::char_traits<char>,std::allocator<char> > host="", std::basic_string<char,std::char_traits<char>,std::allocator<char> > scriptFile="", unsigned short port=1100, HWND__ * hwndParent=0x00230a58, std::basic_string<char,std::char_traits<char>,std::allocator<char> > sInitPackagingResponse="", wchar_t * w_KeyID=0x003c57b8, HWND__ * hList=0x00080e0c, TagEditor * _ProtectSet=0x00488ab0, HWND__ * hWndinoutfiledir=0x00040b72, wchar_t * pszOutFile=0x0012c91c) Line 872 C++
DRMClient.exe!Package::EncodeMediaContent(wchar_t * pszInFile=0x0012e7f0, wchar_t * pszOutFile=0x0012c91c, HWND__ * hwndParent=0x00230a58, std::basic_string<char,std::char_traits<char>,std::allocator<char> > Host="", std::basic_string<char,std::char_traits<char>,std::allocator<char> > UserID="", std::basic_string<char,std::char_traits<char>,std::allocator<char> > InitPackageRequest="", std::basic_string<char,std::char_traits<char>,std::allocator<char> > ScriptFile="", unsigned short Port=1100, HWND__ * hList=0x00080e0c, TagEditor * _ProtectSet=0x00488ab0, HWND__ * hWndinoutfiledir=0x00040b72, HWND__ * hwndEncrypt=0x00230a58) Line 964 + 0xfc bytes C++
DRMClient.exe!Thread(void * pArguments=0x0012c874) Line 145 + 0x12d bytes C++
msvcr80d.dll!_callthreadstartex() Line 348 + 0xf bytes C
msvcr80d.dll!_threadstartex(void * ptd=0x003c9fe0) Line 331 C
I didnt understad why I got the first thread value every time.
and then the application crashed ! 
"Success lies not in the result , But in the efforts !!!!!"
Amit Mistry - petlad -Gujarat-India
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From the title I guess you have a multithreading app, isn't it? The errors say nothing valueable unless you describe at which conditions you got them. Here I suspect you have a problem with synchronization issues [particularly, your std::string object gets corrupted by concurrent accesses within the threads]..
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Arman
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Arman Z. Sahakyan wrote: From the title I guess you have a multithreading app, isn't it? The errors say nothing valueable unless you describe at which conditions you got them.
ya!
Arman Z. Sahakyan wrote: Here I suspect you have a problem with synchronization issues [particularly, your std::string object gets corrupted by concurrent accesses within the threads]..
yes!
when I debug, some time i got some strange values which is actually related with some other thread.
"Success lies not in the result , But in the efforts !!!!!"
Amit Mistry - petlad -Gujarat-India
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Are you doing proper syncronization? I know you do not. 
You should prevent multiple accesses to your string data by giving the monopoly to a single thread at a given time period. std classes are not thread safe. This means you should yourself take care of synchronizing their usage.
See here[^] about synchronization issues.
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Arman
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This is in response to your email to me. I have not worked too much on threads, but will surely help you if I could. My suggestion is that you post it at CP, and you will get plenty of us. Moreover, threads are not something that I've mastered.
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string problem is as remain as but even dw never goes in the any of the cas like
case WAIT_OBJECT_0 + 1: +2 or +3.
what should I do ?
how can i manage it ?
<code>
unsigned __stdcall Thread(void* pArguments )
{
HRESULT hr=NULL;
struct argument_list *Lparam= (argument_list *)pArguments ;
Package pkg;
DWORD dw=WaitForMultipleObjects(ListBoxItemCount,hThread,TRUE,5000 );
switch (dw)
{
case WAIT_OBJECT_0 + 0:
hr=pkg.EncodeMediaContent(Lparam->pszInFile,Lparam->pszOutFil,Lparam->hwndParent,Lparam->Host,Lparam->UserID,Lparam->InitPackageRequest,Lparam->ScriptFile,Lparam->Port,Lparam->hList,Lparam->_ProtectSet,Lparam->hWndinoutfiledir,Lparam->hwndEncrypt);
break;
case WAIT_OBJECT_0 + 1:
hr=pkg.EncodeMediaContent(Lparam->pszInFile,Lparam->pszOutFil,Lparam->hwndParent,Lparam->Host,Lparam->UserID,Lparam->InitPackageRequest,Lparam->ScriptFile,Lparam->Port,Lparam->hList,Lparam->_ProtectSet,Lparam->hWndinoutfiledir,Lparam->hwndEncrypt);
break;
case WAIT_OBJECT_0 + 2:
hr=pkg.EncodeMediaContent(Lparam->pszInFile,Lparam->pszOutFil,Lparam->hwndParent,Lparam->Host,Lparam->UserID,Lparam->InitPackageRequest,Lparam->ScriptFile,Lparam->Port,Lparam->hList,Lparam->_ProtectSet,Lparam->hWndinoutfiledir,Lparam->hwndEncrypt);
break;
case WAIT_FAILED:
break;
case WAIT_TIMEOUT:
break;
}
if(hr==S_OK)
{
MessageBox(0,L"thread gone finished" ,L"therad",0);
_endthreadex( 0 );
}
</code>
"Success lies not in the result , But in the efforts !!!!!"
Amit Mistry - petlad -Gujarat-India
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Supposedly the case WAIT_FAILED works. Anyway ...
A couple of questions;
DWORD dw=WaitForMultipleObjects(ListBoxItemCount,hThread,TRUE,5000 );
What you want to do with this code? Where does LitBoxItemCount come from? Where does hThread come from?
How many threads do you have?
I need to know the answers of these questions before I can say the reasons of your problem.
--
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Arman
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May I send you detail on your email?
because the proper format and written mail is ready.
May I ...?
"Success lies not in the result , But in the efforts !!!!!"
Amit Mistry - petlad -Gujarat-India
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Ok, do it.
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Arman
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have you got any idea or do you need any feed back?
"Success lies not in the result , But in the efforts !!!!!"
Amit Mistry - petlad -Gujarat-India
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This is a multithreading issue and to overcome one needs a proper level of detailed information. What you have posted as code didn't cover all the details and thus you should provide more details. I've already asked about the questions that are not clear [at least to me].
--
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Arman
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would you need any thing more specific information?
I am ready to provide you.
"Success lies not in the result , But in the efforts !!!!!"
Amit Mistry - petlad -Gujarat-India
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I need your little help. when and how the thread manage?
Suppose
I have four thread
hThread[0] = (HANDLE)_beginthreadex(NULL, 0, &Thread ,&l,NULL, &threadID);
hThread[1] = (HANDLE)_beginthreadex(NULL, 0, &Thread ,&l,NULL, &threadID);
hThread[2] = (HANDLE)_beginthreadex(NULL, 0, &Thread ,&l,NULL, &threadID);
hThread[3] = (HANDLE)_beginthreadex(NULL, 0, &Thread ,&l,NULL, &threadID);
and the global function
unsigned __stdcall Thread(void* pArguments )
{
HRESULT hr=NULL;
struct argument_list *Lparam= (argument_list *)pArguments ;
Package pkg;
threadID++;
DWORD dw=WaitForMultipleObjects(ListBoxItemCount,<big>hThread[threadID]</big>,TRUE,5000 );
switch (dw)
{
case WAIT_OBJECT_0 + 0:
hr=pkg.EncodeMediaContent(Lparam->pszInFile,Lparam->pszOutFil,Lparam->hwndParent,Lparam->Host,Lparam->UserID,Lparam->InitPackageRequest,Lparam->ScriptFile,Lparam->Port,Lparam->hList,Lparam->_ProtectSet,Lparam->hWndinoutfiledir,Lparam->hwndEncrypt);
break;
case WAIT_OBJECT_0 + 1:
hr=pkg.EncodeMediaContent(Lparam->pszInFile,Lparam->pszOutFil,Lparam->hwndParent,Lparam->Host,Lparam->UserID,Lparam->InitPackageRequest,Lparam->ScriptFile,Lparam->Port,Lparam->hList,Lparam->_ProtectSet,Lparam->hWndinoutfiledir,Lparam->hwndEncrypt);
break;
case WAIT_OBJECT_0 + 2:
hr=pkg.EncodeMediaContent(Lparam->pszInFile,Lparam->pszOutFil,Lparam->hwndParent,Lparam->Host,Lparam->UserID,Lparam->InitPackageRequest,Lparam->ScriptFile,Lparam->Port,Lparam->hList,Lparam->_ProtectSet,Lparam->hWndinoutfiledir,Lparam->hwndEncrypt);
break;
case WAIT_FAILED:
break;
case WAIT_TIMEOUT:
break;
}
if(hr==S_OK)
{
MessageBox(0,L"thread gone finished" ,L"therad",0);
_endthreadex( 0 );
}
threadID--;
return 0;
}
how can i decide the when which thread come at hThread[],
"Success lies not in the result , But in the efforts !!!!!"
Amit Mistry - petlad -Gujarat-India
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Arman Z. Sahakyan wrote: What you want to do with this code? Where does LitBoxItemCount come from? Where does hThread come from?
How many threads do you have?
What you want to do with this code?
with this code i am tring to synchronize my threads.
Where does LitBoxItemCount come from?
this will come from the listview control (itemcount).I put in my code as global so Global function Thread can use it.
Where does hThread come from?
hThread is array of handle which assigne the thread.
How many threads do you have?
well ,for sample application have created the three worker thread (means if there are total three files in the listview control so itemcount will be three means LitBoxItemCount)
"Success lies not in the result , But in the efforts !!!!!"
Amit Mistry - petlad -Gujarat-India
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Hi,
my requirement is need of physical font name. ie arial.ttf with path for Arial and one more problem in not from registry any other way.
Thanks in advance!
Murali.M
Have A Nice Day!
Murali.M
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Is EnumFont* helpfuls for you (EnumFonts,EnumFontFamilies)
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I got an Email not Reply of (amitmistry_petlad) but what was your question
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hi,
from the font dialog i can select the font name. for my project i need font file name arial.ttf for arial. But it should be possible to read from registry HKEY_LOCAL_MACHINE. for this used need read permission(I think its an problem in vista OS).
Thanks in advance.
Have A Nice Day!
Murali.M
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