C / C++ / MFC

Re: What's the difference between function atof() and _tstof()?

21-Jun-08 6:20

It all depends if either _UNICODE or _MBCS are defined. Please check out MSDN for more information on this topic.

Regards,
Mihai Moga

Dan21-Jun-08 8:08

Dan

21-Jun-08 8:08

Thats the TCHAR mapping for atof/_wtof. By default vc2008 defines TCHAR as a native type. You can use it in vc6, you just need to do so explicitly.

Convert CString to double

bkelly1321-Jun-08 4:27

21-Jun-08 4:27

I am trying to figure out how to convert text in a CString to a double. I found this tutorial:
http://www.codeproject.com/KB/string/cstringmgmt.aspx#Converting%20a%20CString%20to%20an%20integer
and it contains this example code for converting to an integer

CString hex = _T("FAB");
CString decimal = _T("4011");
ASSERT(_tcstoul(hex, 0, 16) == _ttoi(decimal));

I don’t even see an integer declared in that fragment, much less how to convert the CString to an integer or decimal.

Here is what I need:

CString source = _T("1.2e6");
double target;
target = source.FormatAsDouble();

Obviously that does not work. But what will?

Thanks for your time

bkelly1321-Jun-08 4:30

21-Jun-08 4:30

Rats, I miss typed and the edit did not seem to work.
This is what I want to do:

CString source = _T("1.2e6");
double target;
target = source.FormatAsDouble();

Thanks for your time

Ștefan-Mihai MOGA21-Jun-08 4:33

21-Jun-08 4:33

Hi, you should try like this:

CString source = _T("1.2e6");
double target = _tstof( source );

Regards,
Mihai Moga

bkelly1321-Jun-08 4:42

21-Jun-08 4:42

I just compiled and ran that code, it works. But you already knew that.
Thank you Mihai.

The string to be converted will be extracted from a user dialog. The user may make an error in entering the number. Is there a method that will validate the string as being properly formatted or in some other way detect an input error to I can tell the user?

Thanks again.

Thanks for your time

Ștefan-Mihai MOGA21-Jun-08 4:47

21-Jun-08 4:47

Hi, for this task you should check out Ben Hanson's CFilterEdit[^] class. I use in one of my projects and I am gratefull to the author.

Regards,
Mihai Moga

bkelly1321-Jun-08 6:27

21-Jun-08 6:27

RE: CFileterEDit, That class does look good. I downloaded it and the demo.

The file BaseEdit.h contains this reference:

#include <boost/regex.hpp>

This include file in not contained in either of the downloads. BaseEDit.h is the only file containing this include and it has no previous includes that lead me to the file.

Where do I find this file?

Thanks for your time

Ștefan-Mihai MOGA21-Jun-08 6:42

21-Jun-08 6:42

In order to recompile that project, you should consider downloading the boost::regex library from Boost's Official Page/[^].

Regards,
Mihai Moga

bkelly1321-Jun-08 16:05

21-Jun-08 16:05

Hello Mahai,
I have installed the Boost environment, I have added FloatEdit and BaseEdit to my project, and they will compile. Now I see method
double CFloatEdit::GetValue () const
in file FloatEdit.cpp

But I don't see how to apply it to my dialog box.
One of the fields that I want filtered has the ID:
IDC_X_POSITION_EDIT
and string in the box can be accessed via the variable name as follows:
GBE_x_position_string.GetWindowTextW( str );
That puts the value into CString names str.

Can you tell me how to use this FloatEdit to check the inputs to this field?

Thanks for your time

Ștefan-Mihai MOGA21-Jun-08 20:18

21-Jun-08 20:18

Well, FloatEdit will do it for you, it filters data so that you would have a valid floating value/string. It's enought to subclass you CEdit control with this one.

Regards,
Mihai Moga

bkelly1322-Jun-08 2:44