C / C++ / MFC

9-Dec-07 22:44

please go thru MSDN. it has detailed explanation about all the classes mentioned my u.

Regarding combo box

Chandrasekharan P9-Dec-07 22:28

Re: Regarding combo box [modified]

9-Dec-07 22:28

i have a combo box which is of type int. i need to retreive the value that is there in the combo box. that is for example i have 2 values in a combo box. 100 and 200. now when i select 100 from the combo box the value has to send than the index. how can i do that?

CPallini9-Dec-07 23:04

9-Dec-07 23:04

With MFC, ~~the simplest~~ a way is binding the combo to ~~an int~~ a CString variable (use the Add Variable Wizard of VS) and then convert the latter to an int (for instance with _tstoi). You may also use the GetItemData/SetItemData pair to store (and retrieve) directly int values inside combo box items.
If you don't like MFC, the you should retrieve the item text and then convert it to int, i.e.

const INT SIZE=0x100;
TCHAR buffer[SIZE];
INT SelectedInt;
LRESULT sel = SendMessage(hCombo,CB_GETCURSEL,(WPARAM)0, (LPARAM)0);
if ( sel != CB_ERR)
{
  INT n = SendMessage(hCombo,CB_GETLBTEXT,(WPARAM)0, (LPARAM) (LPTSTR) buffer);
  if ( n != CB_ERR)
  {
    SelectedInt = _tstoi(buffer); // here's your integer
  }
}

Please note, I used a 'quick way' of allocating a relatively large buffer (since your combo contains short strings); you can use CB_GETLBTEXTLEN message to know requested buffer size in advance.

BTW, you have also the option to associate the int values to the Item Data of the combo box and retrieve it, whenever needed, via CB_SETITEMDATA message (it is left as an exercise for the reader... Big Grin | :-D

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.

modified on Monday, December 10, 2007 6:40:52 AM

Chandrasekharan P10-Dec-07 0:00

10-Dec-07 0:00

i am using MFC. my requirement is simple. whenever i am trying to acess the variable i am getting the value as the index. i need to value from the combo box.

CPallini10-Dec-07 0:33

10-Dec-07 0:33

You're right, mapping the combo to an int variable make the latter containing the selected index value.
Hence you can either:
(1) Map the combo to a CString variable and the performing _tstoi on the variable.

(2) Getting a pointer (say pCombo) to your combo box class (you can either map a variable or call GetDlgItem) and then:

int nSel = pCombo->GetCurSel();
int nSelValue;
if (nSel != CB_ERR)
{
  CString strValue;
  pCombo->GetLBText(pCombo->GetCurSel(), strValue); 
  nSelValue = _tstoi(strValue); // your integer
}

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.

Chandrasekharan P10-Dec-07 17:21

10-Dec-07 17:21

is there any other way to get the value in the combo box. i am declaring the combo box variable as int. and this variable is used in some more files. so cant change the data type. it can be only int.

CPallini10-Dec-07 22:01

10-Dec-07 22:01

Chandrasekharanp wrote:
so cant change the data type. it can be only int.

In fact, you can. Sometimes a bit refactoring effort it is worthy to do.
Anyway I don't insist on design policies, hence, supposing you int variable name is iCurSel (and your combo box ID is IDC_COMBO), you can do:

int iValue;
UpdateData();
if (iCurSel != CB_ERR)
{
  CString strValue;
  ((CComboBox *) GetDlgItem(IDC_COMBO))->GetLBText(iCurSel, strValue);
  iValue = _tstoi(strValue);
}

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.

Chandrasekharan P10-Dec-07 23:59

problem with network programming

10-Dec-07 23:59

alright.. i have done it. now i have one more thing to do. i need to pass this value to another file. tried using static. but i dont know if i am doing it the right way. it has an error. i tried to declare the variable as

<br />
static int value <br />

in the .h file.

what is the procedure to do that?

Kogee San9-Dec-07 22:11

Kogee San

9-Dec-07 22:11

I have problem to send a message to the server application using send() function using winsock.h. Im trying to send my MAC address information to the server. Firstly, i detect the MAC address at the client side using GetAdaptersInfo API. The problem is the MAC address is an unsigned character. The send() function could not send this type of message. The error would produce 'error C2664: 'send' : cannot convert parameter 2 from unsigned char [] to const char. I tried to convert the unsigned char to const char using casting but it is still the same. Maybe i did the casting wrong. How can i solve this? Is there any examples? Thanks

Re: problem with network programming

Cedric Moonen9-Dec-07 22:24

Cedric Moonen

9-Dec-07 22:24

Muhamad Hazwan Halim wrote:
Maybe i did the casting wrong. How can i solve this?

Maybe by posting what you did so that we can see ? Without code it's quite a challenge to tell where you are wrong.
Usually, a casting is sufficient.

Cédric Moonen
Software developer

Charting control [v1.2]

Re: problem with network programming

CPallini9-Dec-07 22:43