C / C++ / MFC

Re: Is there anyway to access directly?

22-Jul-03 9:33

download the file to the temp folder, and everything works well

Don't try it, just do it! Wink | ;-)

ATC22-Jul-03 11:03

ATC

22-Jul-03 11:03

Re: Is there anyway to access directly?

Alexander ^M.,23-Jul-03 2:11

Re: Is there anyway to access directly?

23-Jul-03 2:11

no way... this kind of database doesn't support your wishes!
better try ms sql or mysql

Don't try it, just do it! Wink | ;-)

Terry O'Nolley24-Jul-03 3:09

Terry O'Nolley

24-Jul-03 3:09

I just went through this same problem with an app I am developing. The drivers for Access do not allow remote connections. I had to export my Access database and import it into MySQL and the ODBC driver for MySQL allows you to specify a URL for the server and the database name on the server.

I'm going to live forever or die trying!

Array definition global vs local?

spaced_out22-Jul-03 6:27

22-Jul-03 6:27

I can define an array in my local variables (to a certain function), but I am having trouble defining that array as a global array that I could use in all of my subfunctions.

Here is how I define the variable in my local area (this works)

<br />
//***********THIS WORKS AND IS WAHT I HAVE****************  it is in my .cpp source file<br />
void CMyDialog::OnMyFuntion() //my local function(subroutine? I don't know the right word?)<br />
{<br />
<br />
    double f1, m_div;  //defining a itermediate variable - I will remove this later when array is fully funtional<br />
    double ValuesArray[200]; // local definition of Array<br />
	<br />
	ifstream inf;                  <br />
	inf.open("Testdata1tab.txt");   //reading data in from text file<br />
<br />
	for (int i=0; i < 199; i++)    // loop 200 times for 200 lines of data<br />
	{<br />
		inf >> f1;             // read value into my temp variable f1<br />
		ValuesArray[i] = f1;   // transfer to array value at location [i]<br />
<br />
		Value = ValuesArray[i]/m_div;  //calculate another value<br />
	}<br />
<br />
    inf.close();<br />
	}<br />
}<br />

When I try to define the array in my .h file as a public variable, I get a runtime error. Here is how I try to define the array:

<br />
//************THIS DOES NOT WORK *************** PLEASE HELP<br />
class CMyDialog : public CDialog<br />
{<br />
// Construction<br />
public:<br />
	CMyDialog(CWnd* pParent = NULL);   // standard constructor<br />
// Dialog Data<br />
	//{{AFX_DATA(CMyDialog)<br />
	enum { IDD = IDD_MY_DIALOG };<br />
	double ValuesArray[200];<br />
		// NOTE: the ClassWizard will add data members here<br />
	//}}AFX_DATA<br />

I leave the .cpp file at the top the same, except that I remove the double ValuesArray[200]; line.
I am probaly doing several things wrong. Any help will be more than welcome.

I wish I could type better ...

John M. Drescher22-Jul-03 6:36

22-Jul-03 6:36

spaced_out wrote:
I get a runtime error.

Confused | :confused:

That sounds like visual basic to me... You mean exception? Which one Access Violation or Division by zero??

John

spaced_out22-Jul-03 8:49

22-Jul-03 8:49

Sorry about that, is says I have an illegal operation. (too many different languages to keep up with.)

I am putting the read in values into a List Control. The scroll bar appears when I execute, but then it just stops before I see the data?

Here is the error message:

MYSOURCE caused an invalid page fault in<br />
module MSVCRT.DLL at 0167:7800a796.<br />
Registers:<br />
EAX=5f4b64b0 CS=0167 EIP=7800a796 EFLGS=00210246<br />
EBX=0063f600 SS=016f ESP=00540000 EBP=00540020<br />
ECX=005400a4 DS=016f ESI=817ce080 FS=5b67<br />
EDX=bff76855 ES=016f EDI=005400cc GS=0000<br />
Bytes at CS:EIP:<br />
55 8b ec 83 ec 04 53 56 57 fc 89 45 fc 33 c0 50 <br />
Stack dump:<br />
bff76849 005400cc 0063f600 005400e8 005400a4 005401d8 bff76855 0063f600 005400b4 bff87fe9 005400cc 0063f600 005400e8 005400a4 5f493801 00540290

I wish I could type better ...

John M. Drescher22-Jul-03 8:53

22-Jul-03 8:53

Are you 100% sure that you are not stepping past the end of the array? Using an invalid index < 0 or > 199..

John

spaced_out22-Jul-03 17:37

22-Jul-03 17:37

Good call. I don't know how I was doing it, but that change let me run the code. Unfortunately, after exit the dialog I get a new error message. I guess it works up to that point and that is something.

THanks. Helpful comments.

I wish I could type better ...

Michael P Butler22-Jul-03 6:48

Michael P Butler

22-Jul-03 6:48

What error message do you get?

My first thoughts would be to move the declaration to outside of the ClassWizard generated code

class CMyDialog : public CDialog
{
// Construction
public:
    CMyDialog(CWnd* pParent = NULL); // standard constructor
    // Dialog Data
    //{{AFX_DATA(CMyDialog)
    enum { IDD = IDD_MY_DIALOG };
       // NOTE: the ClassWizard will add data members here
    //}}AFX_DATA
    double ValuesArray[200];
};

Michael

'War is at best barbarism...Its glory is all moonshine. It is only those who have neither fired a shot nor heard the shrieks and groans of the wounded who cry aloud for blood, more vengeance, more desolation. War is hell.' - General William Sherman, 1879

spaced_out22-Jul-03 17:44

22-Jul-03 17:44

I moved it outside, but I still get an error (once the code is done running). It works up until that point. Thanks to me changing the size of the array. I swear I had it set up correct, but I guess not.

This is the error message I get when I do it inside the ClassWizard zone

MYSOURCE caused an invalid page fault in<br />
module MSVCRT.DLL at 0167:78009dd3.<br />
Registers:<br />
EAX=00000000 CS=0167 EIP=78009dd3 EFLGS=00210246<br />
EBX=0063f600 SS=016f ESP=00540000 EBP=00540034<br />
ECX=005400dc DS=016f ESI=817f7600 FS=20d7<br />
EDX=bff76855 ES=016f EDI=00540104 GS=0000<br />
Bytes at CS:EIP:<br />
55 8b ec 56 8b 75 18 57 bf 20 05 93 19 39 3e 74 <br />
Stack dump:<br />
7800a7bc 00540104 0063f600 00540120 005400dc 5f4b5948 00000000 00000000 00000000 00540104 817f7600 0063f600 5f4b5948 00540058 bff76849 00540104

This is what I get if I am outside the Class Wizard stuff:

MYSOURCE caused an invalid page fault in<br />
module MSVCRT.DLL at 0167:78009dd3.<br />
Registers:<br />
EAX=00000000 CS=0167 EIP=78009dd3 EFLGS=00210246<br />
EBX=0063f600 SS=016f ESP=00540000 EBP=00540034<br />
ECX=005400dc DS=016f ESI=817f7c40 FS=3227<br />
EDX=bff76855 ES=016f EDI=00540104 GS=0000<br />
Bytes at CS:EIP:<br />
55 8b ec 56 8b 75 18 57 bf 20 05 93 19 39 3e 74 <br />
Stack dump:<br />
7800a7bc 00540104 0063f600 00540120 005400dc 5f4b5948 00000000 00000000 00000000 00540104 817f7c40 0063f600 5f4b5948 00540058 bff76849 00540104

Keeping in ming that if I define the array inside of the subroutine-locally (or function? I don't know the right word.) I get no error at all???

I wish I could type better ...

David Crow22-Jul-03 9:02

David Crow

22-Jul-03 9:02

spaced_out wrote:
for (int i=0; i < 199; i++) // loop 200 times for 200 lines of data

FYI, this only loops 199 (0-198) times. That's not the issue at hand, though.

When you are read from the ValuesArray[] array, adding the values to the list control, what line of code causes the error? Is it an access violation, or a fired assertion?

spaced_out22-Jul-03 17:50

22-Jul-03 17:50

Thanks for the 0-198 clarification.

The error is posted in my reply above. I have NO IDEA what it means?

I wish I could type better ...

Alexander ^M.,22-Jul-03 9:14

22-Jul-03 9:14

hehe, i'm sure it is a stack overflow... because of page fault...
you define the CDialog class local in the InitInstance function of the program, right??
then it makes no difference, if you place the whole class in stack or just the 200 doubles.

define the CDialog class GLOBAL, then it should work!

Don't try it, just do it! Wink | ;-)

John M. Drescher22-Jul-03 10:30

22-Jul-03 10:30

200 doubles is not a lot of memory.

John

spaced_out22-Jul-03 18:06

22-Jul-03 18:06

Do you have another way for me to define these numbers that would take up less space?

Instead of double?

If so let me know.

I wish I could type better ...

John M. Drescher22-Jul-03 18:39

22-Jul-03 18:39

My point is that 200 doubles only takes 800 bytes of memory. Your stack is over a megabyte. So the memory allocation is insignifigant... I have programs that allocate over a gigabyte of data with no probelem. They do not put it on the stack though....

John

Alexander ^M.,23-Jul-03 1:30

23-Jul-03 1:30

next time better take a calculator!
200*sizeof(double)=200*8=1600bytes!

Don't try it, just do it! Wink | ;-)

John M. Drescher23-Jul-03 3:44

23-Jul-03 3:44

You are correct a double is 8 bytes... Anyways 1600 bytes on the stack is still not signifigant..

John

Problem Solved!!

spaced_out22-Jul-03 18:05