C / C++ / MFC

Bob Ciora26-Jan-05 9:21

Bob Ciora

26-Jan-05 9:21

Actually... CString has a LPCTSTR operator that will perform the conversion automatically in many cases. So:

CString sFloat = "123.45";

// This will compile without error and run successfully:
const char * szText = sFloat;

// So will this:
float boxval;
int nArgs = sscanf(sFloat, "%s", &boxval);

// As will this:
double d = atof(sFloat);

In all three cases, the compiler understands (based on the l-value in the assignment statements and the prototypes for sscanf and atof) that you're using the LPCTSTR operator for CString.

The code above will compile and run successfully, and boxval and d will be 123.45.

I have a sneaking suspicion that you've changed something elsewhere in the program, even a minor change, and it fixed the problem.

Bob Ciora

Member 166473326-Jan-05 9:31

26-Jan-05 9:31

CString sFloat = "123.45";
const char * szText = sFloat;

This gives me the following error;
error C2440: 'initializing' : cannot convert from 'class CString' to 'const char *'

float boxval;
int nArgs = sscanf(sFloat, "%s", &boxval);

error C2664: 'sscanf' : cannot convert parameter 1 from 'class CString' to 'const char *'

double d = atof(sFloat);

error C2664: 'atof' : cannot convert parameter 1 from 'class CString' to 'const char *'

Thank you so much!!!

David Crow26-Jan-05 9:59

26-Jan-05 9:59

There are some underlying issues here that have not been explained. Did you use AppWizard to create the project? If so, what type of project is it?

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

Member 166473326-Jan-05 10:06

26-Jan-05 10:06

Sorry, I'm new to all of this.

I did use AppWizard to create the project with eMbedded visual C++ 3.0 for Pocket PC 2002 application.
Shall it change anything?
Sorry to keep on bothering you all!
Thanks.

David Crow26-Jan-05 10:11

26-Jan-05 10:11

Anonymous wrote:
I did use AppWizard to create the project with eMbedded visual C++ 3.0 for Pocket PC 2002 application.

By this I assume it is not Visual Studio v6.

Anonymous wrote:
Shall it change anything?

The compiler errors you are seeing hint at MFC not being properly defined within the project. As has already been pointed out, CString has an LPCTSTR operator and for that not to work means something is wrong further upstream.

Anonymous wrote:
Sorry to keep on bothering you all!

It's definitely not a bother. But, like most crime dramas on tv, it helps to provide the detective with all pertinent information up front so that s/he can look for clues in all the right places.

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

Bob Ciora26-Jan-05 10:43

Bob Ciora

26-Jan-05 10:43

Ok, you fixed the problem, so I'm done Smile | :)

Good luck with the rest of your app!

Bob Ciora

David Crow26-Jan-05 8:53

26-Jan-05 8:53

I'm not sure exactly what you are after here but converting text to double, as the subject implies, is as simple as the code snippet I provided earlier. The other code you have is definitely not necessary. You appear to be doing:

text --> double --> text

Is there a point to this exercise? If you are simply wanting to show in a message box what was typed, two lines of code will suffice:

GetDlgItemText(IDC_EDITBOX, txtEdit);
AfxMessageBox("Value is " + txtEdit);

If you need the value for calculation reasons, just call atof(txtEdit).

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

Tom Wright26-Jan-05 8:45

Tom Wright

26-Jan-05 8:45

Ah...again is it just me or, why don't you just set your edit box to value and float. That way you won't have to convert anything.

Tom Wright
tawright915@yahoo.com

Member 166473326-Jan-05 8:53

26-Jan-05 8:53

That's right but if I do that I'd have to write my function as many times as I have Edit boxes with just the name of the float variable changing.
I'd like to do something more generic. It would all work fine if I could convert a string to a float! Frown | :-(

Thanks for the help though!

CDialog Question

Anonymous26-Jan-05 5:53

26-Jan-05 5:53

How do I find out if a Dialog box is open?

I am trying to do a popup dialog box. When user holds down R mouse button a dialog appear and will disappear when R mouse button is release.

I am able to invoke the dialog but I am having problem terminating the dialog

David Crow26-Jan-05 5:59

26-Jan-05 5:59

Anonymous wrote:
I am able to invoke the dialog but I am having problem terminating the dialog

Is it modal or modeless?

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

Anonymous26-Jan-05 6:26

26-Jan-05 6:26

modal

David Crow26-Jan-05 6:44

26-Jan-05 6:44

By definition, a modal dialog box remains active until it has been dismissed. This would keep the window that owns the dialog (i.e., parent) from seeing the right mouse button.

Perhaps if you provided a bit more information as to what you are doing, an alternative solution could be offered.

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

poiut26-Jan-05 8:36

poiut

26-Jan-05 8:36

Ahh that's why it wouldn't close it when I tried EndDialog.

Currently I am using Scrollview, I have a bunch of object draw on the screen. When user right click on the object it would pop up a dialog with information about the object, but would disappear once the mouse button is released.

Should I be doing it as modaless?

David Crow26-Jan-05 8:41

26-Jan-05 8:41

poiut wrote:
Should I be doing it as modaless?

I would lean in that direction.

"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow

Blake Miller26-Jan-05 8:43

Blake Miller

26-Jan-05 8:43

Yes at least make it modelss, but even better would be a pop up window that is NOT a dialog at all.
It can still be a child of the parent window, but it would not attempt to capture messages and events like a dialog would.

Anonymous26-Jan-05 9:20

26-Jan-05 9:20

Can you point me in the right direction?
Any article/example or function on it?

Thanks

Currently I am reading
http://www.codeproject.com/dialog/csettingsdlg.asp
on Modaless

Blake Miller26-Jan-05 11:26

Blake Miller

26-Jan-05 11:26

Derive an MFC class (assuming that is what you are using) from CWnd and add handlers for it to display your information.
Then call Create() to create the window where ever you need it to show up on screen.
You can 'hide' and 'show' it as necessary, send it updated text, and MoveWindow it as the user moves his mouse around to select different items.
Before your main window ends, you should delete the window you created.

poiut26-Jan-05 9:37

poiut

26-Jan-05 9:37

Thanks David & Blake.
I got modlass working Smile | :)

dsadas

Anonymous26-Jan-05 5:08

Displaying Tooltiptext -Problem

26-Jan-05 5:08

dsadasdas

Pazzuzu26-Jan-05 4:55

Pazzuzu

26-Jan-05 4:55

Hi,

Iam using ToolBarControl & in my "ToolTipsHandler" which is an event declared in the message map as follows

BEGIN_MESSAGE_MAP(C_ListPageTemp, CDialog)
//{{AFX_MSG_MAP(C_ListPageTemp)
ON_NOTIFY_EX(TTN_NEEDTEXTA,0,ToolTipsHandler)
//}}AFX_MSG_MAP
END_MESSAGE_MAP()

Now my "ToolTipsHandler" function goes like this

*****************************************
TOOLTIPTEXT *pTTT = (TOOLTIPTEXT *)pNMHDR;
UINT nID =pNMHDR->idFrom;
pTTT->lpszText = MAKEINTRESOURCE(nID);
pTTT->hinst = AfxGetResourceHandle();
return TRUE;
*********************************************

Now instead of taking the tooltiptext from the ResourceStringtable,I want to provide my own strings(decided upon,on which language the tooltip text should appear.This language string, I will be getting from a part of my program which Iam not showing here.)

Will be getting this language dependent string in "T_String" type where "T_String" is of type

typedef std::wstring T_String;

I tried to provide my string as follows.

T_String test;//(string which I get from a part of my Program ,depending on language).
pTTT->lpszText =const_cast<lptstr>(test).

It compiled,but the tooltip displayed was a junk value.
Is this(pTTT->lpszText),the right place to give my string in the "TOOLTIPTEXT" structure or should I use the "szText" member.
If so,How would I make the necessary conversions.

Would be nice if someone could tell me with a code snippet..
Thanks..

Re: Displaying Tooltiptext -Problem

V.26-Jan-05 5:11

26-Jan-05 5:11

FROM MSDN:

In writing your tool tip notification handler, you need to use the TOOLTIPTEXT structure. The members of the TOOLTIPTEXT structure are:

typedef struct {
NMHDR hdr; // required for all WM_NOTIFY messages
LPTSTR lpszText; // see below
WCHAR szText[80]; // buffer for tool tip text
HINSTANCE hinst; // see below
UINT uflags; // flag indicating how to interpret the
// idFrom member of the NMHDR structure
// that is included in the structure
} TOOLTIPTEXT, FAR *LPTOOLTIPTEXT;
hdr
Identifies the tool that needs text. The only member of this structure you might need is the control's command ID. The control's command ID will be in the idFrom member of the NMHDR structure, accessed with the syntax hdr.idFrom. See NMHDR for a discussion of members of the NMHDR structure.
lpszText
Address of a string to receive the text for a tool.
szText
Buffer that receives the tool tip text. An application can copy the text to this buffer as an alternative to specifying a string address.
hinst
Handle of the instance that contains a string resource to be used as the tool tip text. If lpszText is the address of the tool tip text, this member is NULL.
When you handle the TTN_NEEDTEXT notification message, specify the string to be displayed in one of the following ways:

Copy the text to the buffer specified by the szText member.
Copy the address of the buffer that contains the text to the lpszText member.
Copy the identifier of a string resource to the lpszText member, and copy the handle of the instance that contains the resource to the hinst member

I think you can try using szText. Remember it can only hold 80 characters, which is not much.

good luck.
(let me now if it worked? tnx)

"If I don't see you in this world, I'll see you in the next one... and don't be late." ~ Jimi Hendrix

Accessing float from an Edit Box (MFC)

Member 166473326-Jan-05 4:53