C / C++ / MFC Discussion Boards

Re: Save as Excel file

Davitor23-Sep-09 18:13

Davitor

23-Sep-09 18:13

thanks for reply .I know that change the extension by using as Save As option.But how it is possible through code.

ODBC error: Expression too complex Expression too complex [modified]

narendra91122-Sep-09 18:53

narendra911

22-Sep-09 18:53

Hi,
I have a interface to interact with MS-Access database file. I m using CODBCRecordset for accessing DB.
CODBCRecordset class[^]

It was working fine untill I added new field in one of the table.

I added new field ("Lock1" - a integer field) in table (called "Quotation_DB").
This table have bunch of data (int,double,strings). I have a button in my interface which will set this "Lock1" field to 0/1 in separate function. when i click this button i get following error.
//==================
Expression too complex
Expression too complex
//==================
yes it is printing same message twice.

any kind of help will be good to me. Please let me know if i have to provide more information.

This is what i m doing in my function.

BOOL LockUnlockQuotation(BOOL flg_lock)
{

    CODBCRecordset m_RS_RFQ(&DataBase);
    BOOL flg_update = false;

    if( !m_RS_RFQ.Open("SELECT * FROM \"Quotation_DB\"") )
    {
        TRACE("Failed to run query: \"%s\"\n","SELECT * FROM \"Quotation_DB\"");
        return false;
    }
    else
    {
        if(!m_RS_RFQ.IsEOF())
        {
            m_RS_RFQ.MoveFirst();
        }

        CString Quot_revID_db="";
        //get record set
        while(!m_RS_RFQ.IsEOF())
        {
            Quot_revID_db=m_RS_RFQ.GetString("QuotID");
            if(Quot_revID.Compare("MyQoute2009")==0)
            {
                m_RS_RFQ.Edit();
                m_RS_RFQ.Field("Lock")=1;//setting field value

                m_RS_RFQ.Update();//code is throwing error at this point


                flg_update =true;
                break;
            }
            m_RS_RFQ.MoveNext();
        }
        m_RS_RFQ.Close();
    }

    return flg_update;

}

modified on Wednesday, September 23, 2009 3:08 PM

Re: ODBC error: Expression too complex Expression too complex [modified]

narendra91123-Sep-09 5:44

narendra911

23-Sep-09 5:44

is there any fix for this?

modified on Wednesday, September 23, 2009 2:59 PM

ODBC error: Expression too complex

narendra91122-Sep-09 18:52

narendra911

22-Sep-09 18:52

Hi,
I have a interface to interact with MS-Access database file. I m using CODBCRecordset for accessing DB.
CODBCRecordset class[^]

It was working fine untill I added new field in one of the table.

I added new field ("Lock1" - a integer field) in table (called "Quotation_DB").
This table have bunch of data (int,double,strings). I have a button in my interface which will set this "Lock1" field to 0/1 in separate function. when i click this button i get following error.
//==================
Expression too complex
Expression too complex
//==================
yes its print same message twice.

any kind of help will be good to me. Please let me know if i have to provide more information.

This is what i m doing in my function.

BOOL LockUnlockQuotation(BOOL flg_lock)
{

    CODBCRecordset m_RS_RFQ(&DataBase);
    BOOL flg_update = false;

    if( !m_RS_RFQ.Open("SELECT * FROM \"Quotation_DB\"") )
    {
        TRACE("Failed to run query: \"%s\"\n","SELECT * FROM \"Quotation_DB\"");
        return false;
    }
    else
    {
        if(!m_RS_RFQ.IsEOF())
        {
            m_RS_RFQ.MoveFirst();
        }

        CString Quot_revID_db="";
        //get record set
        while(!m_RS_RFQ.IsEOF())
        {
            Quot_revID_db=m_RS_RFQ.GetString("QuotID");
            if(Quot_revID.Compare("MyQoute2009")==0)
            {
                m_RS_RFQ.Edit();
                m_RS_RFQ.Field("Lock")=1;//setting field value

                m_RS_RFQ.Update();//code is throwing error at this point


                flg_update =true;
                break;
            }
            m_RS_RFQ.MoveNext();
        }
        m_RS_RFQ.Close();
    }

    return flg_update;

}

Re: ODBC error: Expression too complex [modified]

narendra91123-Sep-09 5:44

narendra911

23-Sep-09 5:44

is there any fix for this?

modified on Wednesday, September 23, 2009 2:59 PM

Calling The Thread function

VVVimal22-Sep-09 18:50

VVVimal

22-Sep-09 18:50

UNIT SimpleThread::ThreadFunc(LPARAM lp)
{
While(1)
{
printf("Test");

}
}
SimpleThread::Start()
{
DWORD dwThreadId, dwThrdParam = 1;
threadHandle = CreateThread(
NULL,
0,
SimpleThread::ThreadFunc,
dwThrdParam,
0,
&dwThreadId);
}

When call the thread it does't get called. Also somtimes it called but the while loop terminate within a while.Can any give me solution to this

Re: Calling The Thread function

Naveen22-Sep-09 19:26

Naveen

22-Sep-09 19:26

VVVimal wrote:
SimpleThread::Start()

What happens to the main thread after the creation of the thread?

nave

[OpenedFileFinder] [My Blog]

Re: Calling The Thread function

chandu00422-Sep-09 20:44

chandu004

22-Sep-09 20:44

AFAIK,
we cannot use a normal member function of a class as a thread.
there is a different procedure for this, let me remember.
but as a temporary solution, i can suggest you to use ThreadFunc as a global function and see.
good luck.

--------------------------------------------
Suggestion to the members:
Please prefix your main thread subject with [SOLVED] if it is solved.
thanks.
chandu.

Thread

VVVimal22-Sep-09 18:49

VVVimal

22-Sep-09 18:49

Re: Thread

CPallini22-Sep-09 20:54

CPallini

22-Sep-09 20:54

How can you even compile your code (there are a lot of errors)?
The following one works properly

#include <windows.h>
class SimpleThread
{
  
  static DWORD WINAPI ThreadFunc(LPVOID p)
  {
    while(1)
    {
      printf("Test");

    }
  }
public:
  void SimpleThread::Start()
  {
    DWORD dwThreadId, dwThrdParam = 1;
    HANDLE threadHandle;
    threadHandle = CreateThread(
      NULL,
      0,
      ThreadFunc,
      &dwThrdParam,
      0,
      &dwThreadId);
  }
};

void main()
{
  SimpleThread t;
  t.Start();
  while (1);
}

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

[My articles]

Question about structure [modified]

liang30622-Sep-09 16:59

liang306

22-Sep-09 16:59

Hello, everyone

I've wrote a code which will find the intersection of two given Linked lists sorted in increasing order.
Actually the code is running fine now, but I find a problem during compiling, but I dont know the reason,
so, hope someone know what's cause the problem. Thank you!

Problem is, if I put /* dummy.next = NULL; */ in front of /* struct node* tail = &dummy; */,
there will be errors, otherwise, problem running fine. Following is the function I wrote.
Thank you all.

// create a new list with the intersection of two given lists sorted in increasing order

struct node* SortedIntersect(struct node* head1, struct node* head2)
{
 
    struct node dummy;
	 //dummy.next = NULL;
    struct node* tail = &dummy;
    dummy.next = NULL;
   

    while(head1 != NULL && head2 != NULL)
    {
        if(head1->data == head2->data)
        {
            Push(&(tail->next), head1->data);
            tail = tail->next;
            head1 = head1->next;
            head2 = head2->next;
        }
        else if(head1->data > head2->data)
        {
            head2 = head2->next;
        }
        else
        {
            head1 = head1->next;
        }
    }

return dummy.next;
}

modified on Wednesday, September 23, 2009 2:35 PM

Re: Question about structure

Naveen22-Sep-09 18:39

Naveen

22-Sep-09 18:39

is this C or C++?

In C, all the variable declaration should be wrttien in the begining of the function before any other code.

nave

[OpenedFileFinder] [My Blog]

[Solved] What is the 32-bit form of the _InterlockedIncrement intrinsic?

Skippums22-Sep-09 8:15

Skippums

22-Sep-09 8:15

I am attempting to write some atomicInc functions that take 16 or 32 bit signed arguments, and call the appropriate _InterlockedIncrement intrinsic function when compiled in Visual Studio 2008. However, it appears the function _InterlockedIncrement takes a 64-bit integer on my system (Windows XP SP2 64-bit Pro), even though the documentation states that _InterlockedIncrement is the 32-bit version of the function call.

My question is, what intrinsic should I use to atomically increment a 32-bit value? The following is producing an error:

#include <intrin.h>
#pragma intrinsic (_InterlockedIncrement, _InterlockedIncrement16)

// The following compiles without issue on my system
__int16 atomicInc(__int16 *val) {
    return _InterlockedIncrement16(val);
}

// The following generates compiler error C2664 on the line with the return statement,
// '_InterlockedIncrement' : cannot convert parameter 1 from 'volatile int *' to 'volatile long *'"
__int32 atomicInc(__int32 *val) {
    return _InterlockedIncrement  (val);
}

Any help is greatly appreciated. Thanks,

Sounds like somebody's got a case of the Mondays

-Jeff

modified on Tuesday, September 22, 2009 5:37 PM

Re: What is the 32-bit form of the _InterlockedIncrement intrinsic?

cmk22-Sep-09 10:24

cmk

22-Sep-09 10:24

A failing on MS part i think.

http://msdn.microsoft.com/en-us/library/29dh1w7z(VS.80).aspx[^]

__in32 == int, int != long (as data types are concerned).
They should have made __int32 == long.

You have 2 choices:

__int32 atomicInc(__int32 *val) {
return (__int32)_InterlockedIncrement((long*)val);
}

or

__int32 atomicInc(long *val) {
return (__int32)_InterlockedIncrement(val);
}

...cmk

The idea that I can be presented with a problem, set out to logically solve it with the tools at hand, and wind up with a program that could not be legally used because someone else followed the same logical steps some years ago and filed for a patent on it is horrifying.
- John Carmack

Re: What is the 32-bit form of the _InterlockedIncrement intrinsic?

Skippums22-Sep-09 10:53

Skippums

22-Sep-09 10:53

cmk wrote:
__int32 atomicInc(__int32 *val) {
return (__int32)_InterlockedIncrement((long*)val);
}

Do __int32 and __int64 variables have the same alignment requirements in memory? I was under the impression that an __int64 had to have 8-byte alignment, whereas an __int32 had to have only 4-byte alignment. Therefore, wouldn't I have a 50% chance of getting a runtime error when attempting to dereference the __int64*? Will converting an "__int32*" to an "__int64*" always guarantee the bits from the original digit are in the least-significant position, or does this depend on hardware endianess? Thanks,

Sounds like somebody's got a case of the Mondays

-Jeff

Re: What is the 32-bit form of the _InterlockedIncrement intrinsic?

cmk22-Sep-09 10:59

cmk

22-Sep-09 10:59

Not sure I understand your question, how did __int64 enter the discussion ?

_InterlockedIncrement is for 32bit values only (long).
A long is 4 bytes on both 32bit and 64bit systems.

Re: What is the 32-bit form of the _InterlockedIncrement intrinsic?

Skippums22-Sep-09 11:14

Skippums

22-Sep-09 11:14

I didn't realize that type int is logically equivalent to type long... I thought a long was 64-bits (as you can guess, I always use the __intN types for integers so I know how many bits I have to work with)

So if I understand correctly, long and int are both 32-bit signed integer types, are built into ANSI C as keywords, but the compiler can't resolve this equivalence at compile-time? I'm confused... why can't the compiler figure out this equivalence without explicit type conversions? Thanks,

Sounds like somebody's got a case of the Mondays

-Jeff

modified on Tuesday, September 22, 2009 5:21 PM

Re: What is the 32-bit form of the _InterlockedIncrement intrinsic?

cmk22-Sep-09 11:55

cmk

22-Sep-09 11:55

A float is also 4 bytes. They are different types - period, it doesn't matter if they are both integer types.

http://msdn.microsoft.com/en-us/library/s3f49ktz(VS.80).aspx[^]

Re: [Solved] What is the 32-bit form of the _InterlockedIncrement intrinsic?

Randor 22-Sep-09 12:04

Randor

22-Sep-09 12:04

Jeff,

Skippums wrote:
I am attempting to write some atomicInc functions that take 16 or 32 bit signed arguments, and call the appropriate _InterlockedIncrement intrinsic function when compiled in Visual Studio 2008.

This statement shows that you fundamentally do not understand atomicity. While it is probably true that the compiler will optimize the functions above directly into a call to _InterlockedX functions. Your atomic operations have just become subject to compiler optimizer probability.

You need to call the Interlocked functions directly. Do not call them through a proxy function.

Best Wishes,
-David Delaune

Re: [Solved] What is the 32-bit form of the _InterlockedIncrement intrinsic?

Skippums22-Sep-09 12:20

Skippums

22-Sep-09 12:20

I don't understand why, if not actually placed inline, the new code runs the risk of not being thread safe. Can you explain this? As far as I can tell, the value will still be modified and returned by value atomically. Therefore, no matter what the optimizer does, I still always get the correct value returned as well as the correct value set. Seems logical to me, unless the compiler can optimize the intrinsic function to return by reference, which means that the intrinsic is incorrectly implemented. Please let me know how this could possibly not be thread safe.

Sounds like somebody's got a case of the Mondays

-Jeff

Re: [Solved] What is the 32-bit form of the _InterlockedIncrement intrinsic?

Randor 22-Sep-09 13:33

Randor

22-Sep-09 13:33

Jeff,

A context switch[^] can occur at the top of your atomicInc function. Let me go into detail:

For example this simple program:

volatile long m_Lock;
__int32 atomicInc(volatile long * val)
{
	return _InterlockedIncrement(val);
}

int _tmain(int argc, _TCHAR* argv[])
{
	atomicInc(&m_Lock);
	return 0;
}

Lets compile with /FAs and inspect the assembler output:

//Here is the part in main where we call atomicInc

; 13   : 	atomicInc(&m_Lock);

	push	OFFSET ?m_Lock@@3JC			; m_Lock
	call	?atomicInc@@YAHPCJ@Z			; atomicInc
	add	esp, 4

//Here is your atomicInc function:
atomicInc@@YAHPCJ@Z PROC				; atomicInc, COMDAT

; 7    : {

	push	ebp
	mov	ebp, esp
	sub	esp, 64					; 00000040H
	push	ebx
	push	esi
	push	edi

//Now look at all the instructions that are executed before you attempt to atomically increment your variable.
//A context switch CAN take place within this small window your count will NOT be atomic.
//In fact maybe another thread modified it and will cause a deadlock or race condition.
; 8    : 	return _InterlockedIncrement(val);

	mov	eax, DWORD PTR _val$[ebp]
	mov	ecx, 1
	lock	 xadd	 DWORD PTR [eax], ecx
//The line above is the atomic increment instructions.
	inc	ecx
	mov	eax, ecx

; 9    : }

	pop	edi
	pop	esi
	pop	ebx
	mov	esp, ebp
	pop	ebp
	ret	0

The _InterlockedIncrement functions should not be wrapped. By wrapping them you are potentially losing atomicity. You should pray that your compiler optimizes your code and removes the atomicInc function call. (It probably will in Release mode) But keep in mind your code is not atomic at all. Here is what I am saying in laymens terms:

1.) The code you presented is not atomic.
2.) The compiler may optimize and fix the bug you have created.

Good Luck,
-David Delaune

Re: [Solved] What is the 32-bit form of the _InterlockedIncrement intrinsic?

Skippums22-Sep-09 14:00

Skippums

22-Sep-09 14:00

If I understand correctly, you are suggesting the following sequence of events:

1) I call my wrapper method in thread1 passing &m_Lock, but somewhere prior to executing the atomic increment, there is a context switch to thread2.
2) Something in thread2 modifies the value of m_Lock, then switches control back to thread1
3) thread1 then increments the new value of m_Lock

Unless I am missing something, the critical section of these operations is still atomic. My method doesn't know what the value of m_Lock is, so whether I increment it before or after thread2 performs the modification is inconsequential. The only thing that could break this would be if &m_Lock is volatile, which could break the code even if calling the intrinsic directly.

Sure, my function won't necessarily be called and return without a context switch, but it doesn't effect (as far as I can tell) the correctness of the code. Is there something else I am still missing? Thanks for your help thus far,

Sounds like somebody's got a case of the Mondays

-Jeff

Greyscale image from raw data

David Ferreira22-Sep-09 4:57

David Ferreira

22-Sep-09 4:57

I'm coding an mfc active x that gets raw data and appends a header so far I've got it displaying the image but there are elements of green in what should be a grey scale image. I'm using a RGB header and assume that the image has shades of grey beyond that allowed in a 256 bit colour image. So how do i get the green to display as shades of grey. I haven't been able to find a method that creates a grey scale image that is y i'm using the RGB. From what i can see there is none and i need to add a palette to the image which i tried to do but can't even get the shades of green to change to a different colour.
Here is my code if anyone can help me out it would be greatly appreciated.

CClientDC dc(this); // device context for painting

BITMAPINFO bmi;//header struc

bmi.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
bmi.bmiHeader.biWidth  = 208;
bmi.bmiHeader.biHeight = 208;
bmi.bmiHeader.biPlanes = 1;
bmi.bmiHeader.biBitCount = 8;
bmi.bmiHeader.biCompression = BI_RGB;
bmi.bmiHeader.biSizeImage = 0;
bmi.bmiHeader.biXPelsPerMeter = 0;
bmi.bmiHeader.biYPelsPerMeter = 0;
bmi.bmiHeader.biClrUsed = 0;
bmi.bmiHeader.biClrImportant = 0;



LPPALETTEENTRY pPalEntry = NULL; // pal palette
RGBQUAD *pRGB = NULL;
BOOL ret = TRUE;
CPalette palette;

int npalColors = palette.GetEntryCount();

pPalEntry = new PALETTEENTRY[npalColors];
pRGB = new RGBQUAD[npalColors];

palette.GetPaletteEntries(0, npalColors, pPalEntry);

for (int i = 0; i < npalColors; i++)
{
    pRGB[i].rgbRed   = pPalEntry[i].peRed;
    pRGB[i].rgbGreen = pPalEntry[i].peRed;//.peGreen;
    pRGB[i].rgbBlue  = pPalEntry[i].peRed;//.peBlue;
    pRGB[i].rgbReserved = 2;
}


CBitmap bitmap;
bitmap.CreateCompatibleBitmap(&dc,208, 208);
::SetDIBits(dc.m_hDC,bitmap,0,208,m_byImg2,&bmi,DIB_RGB_COLORS);//m_byImg2 is the raw data its a pointer to a byte array
CDC dcMemory;
dcMemory.CreateCompatibleDC(&dc);
CBitmap * pOldBitmap = dcMemory.SelectObject(&bitmap);
SetDIBColorTable(dcMemory, 0, npalColors, pRGB);

dc.StretchBlt(0,0, m_nW,m_nH, &dcMemory, 0,0,208,208 , SRCCOPY);//m_nW and m_nH is width and height of the active x when embedded

Re: Greyscale image from raw data

includeh1022-Sep-09 5:20

includeh10

22-Sep-09 5:20

I think you just want to change green color to gray, is it correct?
if yes, you need to change green color in color table to gray, do not need to worry other data.

Re: Greyscale image from raw data

enhzflep22-Sep-09 20:02

enhzflep

22-Sep-09 20:02

Don't have VS installed, so I can't have a poke around with your code, though the immediate thing that springs to mind is:
Why don't you just desaturate the image pixel-by-pixel.

I.e convert the RGB value of each pixel to HSL. Then change the S channel to 0.0 and convert back to RGB - voilla! One monochrome picture.

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