C / C++ / MFC

Re: File handling in DLL.

27-Jan-09 22:19

To use CFile, the DLL must be an MFC DLL.
Or you need to give MFC support to the DLL.

«_Superman_»

Rajesh R Subramanian28-Jan-09 5:29

Rajesh R Subramanian

28-Jan-09 5:29

I'm giving you a 5 for answering a question like that. You have an awful lot of patience. Smile | :)

It is a crappy thing, but it's life -^ Carlo Pallini

Re: File handling in DLL.

«_Superman_»28-Jan-09 17:09

Best way to pass arguments into a method

28-Jan-09 17:09

Thank you Rajesh.
That is very kind of you. Smile | :)

«_Superman_»

CodingLover27-Jan-09 21:32

27-Jan-09 21:32

Hi all,

I have 6 int values and a char buffer to pass another method. Something like this.

<br />
int MyClassOne::Method()<br />
{<br />
    NemMwthod(1, 2, 3, 4, 5, 6, buffer);<br />
}<br />
<br />
int MyClassTwo::NewMethod(int a, int b, int c, int d, int e, int f, char buffer)<br />
{<br />
    // Do the process<br />
}<br />

Seems it's odd to me. So I do the following.

int MyClassOne::Method()<br />
{<br />
    int* arr = new int[6];<br />
    arr[0] = 1;<br />
    arr[1] = 2;<br />
    arr[2] = 3;<br />
    arr[3] = 4;<br />
    arr[4] = 5<br />
    arr[5] = 6;<br />
    <br />
    NemMwthod(arr, buffer);<br />
    delete[] arr;<br />
}<br />
<br />
int MyClassTwo::NewMethod(int ar[], char buffer)<br />
{<br />
    // Do the process<br />
}

I want to know what's best way to workaround is.

Thanks a lot

I appreciate your help all the time...
CodingLover Smile | :)

epitalon27-Jan-09 21:47

epitalon

27-Jan-09 21:47

In my opinion, both methods are good.
I would prefer the first one, because it involves less copy operations.
As long as there is a fixed low number of integers to pass to the called procedure, the fist one is the best.
If the number of integers is variable, the second one is better.

An intermediate method would be:

int arr[6];
arr[0] = 1;
arr[1] = 2;
arr[2] = 3;
arr[3] = 4;
arr[4] = 5
arr[5] = 6;

NemMwthod(arr, buffer);

Rahul Vaishnav27-Jan-09 21:49

Rahul Vaishnav

27-Jan-09 21:49

You can use
vector or CSimpleArray and pass that as a function parameter.

CPallini27-Jan-09 21:50

27-Jan-09 21:50

They are both legitimate, anyway IMHO the first one is more reliable, since the second one may crash your application if the caller passes an array having the wrong number of items (i.e. array size < 6).
Note that you may force the correct behaviour this way:

struct MyMethodArg
{
 int arr[6];
 char * buffer; // Usual a character buffer 
};

int MyClass::MyMethod(MyMethodArg arg)
{

}

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]

CodingLover27-Jan-09 22:23

27-Jan-09 22:23

Thanks for all the comments, make sense.

But actually that method is call large number of times, say 50 times in one second. The way I workout is fine? I'm testing it, so far so good. Smile | :)

I appreciate your help all the time...
CodingLover Smile | :)

CPallini27-Jan-09 22:27

27-Jan-09 22:27

Which way?
If you use the array then you may choose to allocate it on the stack, instead of the heap, for instance

int a[]={1,2,3,4,5,6};
MyMethod(a,buf);

CodingLover27-Jan-09 22:31

27-Jan-09 22:31

Ya, but I've clear the head once pass the array.

I appreciate your help all the time...
CodingLover Smile | :)

CPallini27-Jan-09 22:39

27-Jan-09 22:39

CodingLover wrote:
Ya, but I've clear the head once pass the array.

CodingLover27-Jan-09 22:47

27-Jan-09 22:47

Sorry sir, it should be heap.

I appreciate your help all the time...
CodingLover Smile | :)

«_Superman_»27-Jan-09 22:25

27-Jan-09 22:25

CodingLover wrote:
I want to know what's best way

Both are fine. Normally what I do is that if a function needs more than 5 parameters, I define a structure for it. It is just a standard that I follow. So its all up to you.

All parameters are passed on the stack and in Visual Studio the default stack space for a thread is 1 MB. So passing a structure will only use one location of the stack rather than 100 locations if you want to pass 100 parameters.

«_Superman_»

CodingLover27-Jan-09 22:31

27-Jan-09 22:31

Actually those methods are in two different classes. Sorry about that, I'm asking it because I've no more knowledge about structures. Is that structures is possible here.

I appreciate your help all the time...
CodingLover Smile | :)

«_Superman_»27-Jan-09 22:42

27-Jan-09 22:42

You can define the structure in a header file and include the header file in both the class files.

«_Superman_»

C Change28-Jan-09 0:44

C Change

28-Jan-09 0:44

A structure is what I would always do too. If there's a natural grouping to these items then having a struct defined for them is good practice anyway, including code readability. You just pass the struct, or a pointer to it, as suits. Nice and clean.

hexadecimal

aswd27-Jan-09 20:56

aswd

27-Jan-09 20:56

how to setting an edit box to prompt the user to enter hexadecimal numbeR?..

Smile | :)

Hamid_RT27-Jan-09 21:15

Hamid_RT

27-Jan-09 21:15

You can derived your class of Editbox and then overwrite WM_CHAR only for digital number for 0..9 and A..F.

Of one Essence is the human race
thus has Creation put the base
One Limb impacted is sufficient
For all Others to feel the Mace
(Saadi )

CPallini27-Jan-09 21:18

27-Jan-09 21:18

AFAIK, you have to write your own code to validate the entered number.
Luckily there are functions like strtol [^] (or _tcstol, if toxcct is nearby Roll eyes | :rolleyes:

) that may greatly help you.
Smile | :)

aswd27-Jan-09 21:20

aswd

27-Jan-09 21:20

ouh..oke!!
let me try 1st..
thanks master!!..

Smile | :)