Return from function - C / C++ / MFC Discussion Boards

Lord Kixdemp27-Oct-06 17:41

27-Oct-06 17:41

Hello everyone!
I'm debugging a program, and, I'm viewing my own binary file in a hex editor for the first time, and that somehow makes me happy... (#define __NO_LIFE_GEEK__) Laugh | :laugh:

Now... Until byte 8 it's alright, but after that it's supposed to write a LPTSTR containing the following text:

You need a SSE2-enabled processor in order to run this program.

However, the 9th char is 03h, which doesn't look like a Y (59h)... I'm writing it like this:

// Get text in CEdit
m_em_errorMsg->GetWindowText(_tempString, m_em_errorMsg->GetWindowTextLength());

// Write it
out.Write(_tempString, m_em_errorMsg->GetWindowTextLength());

(_tempString being the LPTSTR)

So I was wondering if I should write it some other way... Am I wrong? Thanks! Laugh | :laugh:

Windows Calculator told me I will die at 28. Frown | :(

Re: Is LPTSTR a char pointer?

Waldermort27-Oct-06 17:59

Waldermort

27-Oct-06 17:59

If unicode is defined LPTSTR is a wchar_t*, otherwise it's a char*.

Re: Is LPTSTR a char pointer?

Lord Kixdemp27-Oct-06 20:03

Lord Kixdemp

27-Oct-06 20:03

Damn VS set Unicode without my permission! Mad | :mad:

Windows Calculator told me I will die at 28. Frown | :(

Re: Is LPTSTR a char pointer?

Prakash Nadar27-Oct-06 22:16

Prakash Nadar

27-Oct-06 22:16

Lord Kixdemp wrote:
Windows Calculator told me I will die at 28.

you are using wrong tool for wrong purpose.

-Prakash

Re: Is LPTSTR a char pointer?

Lord Kixdemp28-Oct-06 12:18

Lord Kixdemp

28-Oct-06 12:18

Mr.Prakash wrote:
you are using wrong tool for wrong purpose.

I sure am! Laugh | :laugh:

Windows Calculator told me I will die at 28. Frown | :(

CTreeCtrl CheckBox

JBAK_CP27-Oct-06 15:19

JBAK_CP

27-Oct-06 15:19

Hi...I have a dialog box with a tree control that has check-boxes in it. What I need to do is, when any of the check-boxes in the tree control is checked, I need to do some processing, and for now let's just say, I need to put up a messagebox. I added a function for the 'NM_CLICK' message to intercept the left button clicks in the tree control, then I do a 'GetCheck' to see if the button is checked.

When I check the box, the 'GetCheck' function returns a 0 but a checkmark appers in the box. When I uncheck the box, the 'GetCheck' function returns a 1, and the checkmark is removed from the box. So this isn't really helping me figure out when the box is checked and not.

Any help would be greatly appericated.

Here is my code for the 'NM_CLICK'

void CDirectoryCheckDlg::OnClickTree1(NMHDR* pNMHDR, LRESULT* pResult)
{
CPoint pt;
GetCursorPos(&pt);
m_testTree.ScreenToClient(&pt);
UINT uFlags;

HTREEITEM ht = m_testTree.HitTest(pt, &uFlags);

if(ht != NULL)
{
// There is an item under the cursor.
m_testTree.SelectItem(ht);

// See what exactly was under the cursor:
switch(uFlags)
{
case TVHT_ONITEMSTATEICON:
{
// It is the icon (checkbox)
BOOL chkbox = m_testTree.GetCheck(ht);
if(chkbox)
MessageBox("Button is checked");

//CString str;
//str.Format("%d",chkbox);
//MessageBox(str,NULL,NULL);
break;
}
case TVHT_ONITEMBUTTON:
// It is the button
break;

}

}

*pResult = 0;
}

Re: CTreeCtrl CheckBox

Gary R. Wheeler29-Oct-06 1:54

Gary R. Wheeler

29-Oct-06 1:54

When the control issues the NM_CLICK notification, it hasn't changed the state of the checkbox yet.

You might try looking at the TVN_ITEMCHANGED[^] notification. Also look at the general tree control article here[^], especially the section entitled Working with state image indexes.

Software Zen: delete this;

Fold With Us![^]

Return from function

Oliver12327-Oct-06 11:04

Oliver123

27-Oct-06 11:04

This code works fine, but as I learn more about VC++ I wonder if it is OK. I think index exists only within the function, but I'm not sure if it can be returned to targetPrice without problem. There has been no problem so far, but my program isn't finished yet. (basePrice is global.)

int q = GetIndexForPrice(targetPrice );
...
...
...
int CTradingdemoDlg::GetIndexForPrice(double price)
{
int index;
index = (price - basePrice)/ .0025;
return index;
}

Thanks

Re: Return from function

led mike27-Oct-06 11:09

led mike

27-Oct-06 11:09

Oliver123 wrote:
I think index exists only within the function

Yes but int CTradingdemoDlg::GetIndexForPrice(double price)
and
return index;
is handled by the compiler by "copying" the value from the index variable inside the function into the value of the variable outside the function that receives it "int q".

led mike

DWORD to LPCVOID

Cyclone0227-Oct-06 9:27

Cyclone02

27-Oct-06 9:27

hi guys

Could someone please help me to convert from dword to lpcvoid?

This is my code:

LPCVOID voider;
DWORD copytothis;

lpBaseAddress = FakeBF2Start;

but i get an error when i try that:

error C2440: '=' : cannot convert from 'DWORD' to 'LPCVOID'

(that code is not the entire code just so u no its just pseudo but thats the only part that is causing probs)

Thanks in advance

Re: DWORD to LPCVOID

David Crow27-Oct-06 10:16

David Crow

27-Oct-06 10:16

Cyclone02 wrote:
lpBaseAddress = FakeBF2Start;

Perhaps:

lpBaseAddress = (LPCVOID) &FakeBF2Start;

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"Judge not by the eye but by the heart." - Native American Proverb

Re: DWORD to LPCVOID [modified]

Cyclone0228-Oct-06 7:07

Cyclone02

28-Oct-06 7:07

thanks a lot but when i use that code with this :

lpBaseAddress = (lpBaseAddress - (LPCVOID)&RealStart) + (LPCVOID)&FakeStart;

then it does not work it displays this error:

: error C2036: 'LPCVOID' : unknown size
: error C2036: 'LPCVOID' : unknown size

do u no how to fix this?

Thanks

-- modified at 14:33 Saturday 28th October, 2006

Re: DWORD to LPCVOID

Mark Salsbery29-Oct-06 7:17

Mark Salsbery

29-Oct-06 7:17

You're trying to do pointer arithmetic on void pointers. The compiler doesn't know the size
of void so it can't add the pointers. You need to use an appropriate pointer type (LPBYTE,
LPWORD, etc.) for the arithmetic then cast the result to a LPCVOID.

Without knowing what types lpBaseAddress, RealStart, and FakeStart are I can't show you example
code Smile | :)

Mark

Re: DWORD to LPCVOID

Cyclone0229-Oct-06 8:59

Cyclone02

29-Oct-06 8:59

LPCVOID lpBaseAddress
DWORD RealStart
DWORD FakeStart

can u please show me an example code as that would be very helpful.

Thanks

Re: DWORD to LPCVOID

Mark Salsbery29-Oct-06 9:25

Mark Salsbery

29-Oct-06 9:25

Ok it looks like you're adding/subtracting the VALUE of RealStart/FakeStart, not the address,
right?

lpBaseAddress = (LPCVOID)(((BYTE*)lpBaseAddress - RealStart) + FakeStart);

Subtracting the ADDRESS of RealStart then adding the ADDRESS of FakeStart doesn't make sense
to me so I assume that's what you're doing.

Is that what you had in mind?

Mark

Re: DWORD to LPCVOID

Cyclone0230-Oct-06 5:57

Cyclone02

30-Oct-06 5:57

thanks a lot m8 that worked Big Grin | :-D

Can I use bits instead of bytes?

Lord Kixdemp27-Oct-06 9:08

Lord Kixdemp

27-Oct-06 9:08

Hello everyone!
I was just wondering this... I have a variable that I want to write to a file that can have only 4 values, so only 2 bits needed... If I can't write plain 2 bits to a file, what's the most "efficient" thing I can use? char?
Thanks! (and sorry if I'm being teh big n00b... Laugh | :laugh:

)

Windows Calculator told me I will die at 28. Frown | :(

Re: Can I use bits instead of bytes?

led mike27-Oct-06 9:16

led mike

27-Oct-06 9:16

A single byte is the smallest size you can write to disk.

"Alot of the people on this forum are incredibly stupid, thinking that the internet is real"
Score: 1.0 in the Soap Box

Re: Can I use bits instead of bytes?

Lord Kixdemp27-Oct-06 9:24

Lord Kixdemp

27-Oct-06 9:24

Yeah, I never saw a text file with 12.7 bytes... Laugh | :laugh:

Windows Calculator told me I will die at 28. Frown | :(

Re: Can I use bits instead of bytes?

George L. Jackson27-Oct-06 12:07

George L. Jackson

27-Oct-06 12:07

The smallest unit you can write is a WORD (32 bits is the most common WORD size, nowadays). However, if you wrote just a WORD to a hard drive that writes 4K sized blocks, you will have a lot of unutilized space.

Re: Can I use bits instead of bytes?

Michael Dunn27-Oct-06 16:15

Michael Dunn

27-Oct-06 16:15

You're thinking of a "CPU word" which is the size of the CPU's integer registers (32 or 64 bits on modern desktop CPUs).
The C/C++ type WORD is always two bytes.

--Mike--
Visual C++ MVP Cool | :cool: