C / C++ / MFC

7-Sep-09 21:14

Such code is removed by the preprocessor, hence the compiler won't see it and the chances it will be ever executed looks very little... Roll eyes | :rolleyes:

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]

Strings in the code

Nick_1117-Sep-09 19:03

Nick_111

7-Sep-09 19:03

Let us say i have a number of printf commands and strings in my code
eg printf("Hi"),printf("Hello") and other strings
Are all these strings stored in a string table automatically?

Naveen7-Sep-09 20:21

Naveen

7-Sep-09 20:21

No. Those strings are not stored in the string table. I guess such strings are stored in the .rdata section of the binary where as the string table and its strings are stored in the .rsrc section of the binary file.

nave

[OpenedFileFinder] [My Blog]

Iain Clarke, Warrior Programmer

Iain Clarke, Warrior Programmer7-Sep-09 21:03

7-Sep-09 21:03

This (almost) exact same question was posted yesterday.
http://www.codeproject.com/Messages/3187912/Strings-in-EXE.aspx[^]
And I've a vague memory of it beign posted a couple of days before.

Are you both in the same class? Bidding for the same project!

I find it a little spooky...

Iain.

I have now moved to Sweden for love (awwww).
If you're in Scandinavia and want an MVP on the payroll (or happy with a remote worker), or need cotract work done, give me a job! http://cv.imcsoft.co.uk/[^]

Michael Schubert7-Sep-09 22:30

Michael Schubert

7-Sep-09 22:30

Iain Clarke, Warrior Programmer wrote:
Are you both in the same class?

Either that or he created 2 accounts in order to increase the penetration of this forum.

CPallini7-Sep-09 21:10

7-Sep-09 21:10

Nope. They weren't yesterday and probably they aren't today.
If you wish to know where are them, then use an editor able to show binary files content (in a meaningful way) as, for instance, Notepad++ with the Hex Editor plugin.
Smile | :)

Closing of dialog box crashes application

Michael Schubert7-Sep-09 22:34

Michael Schubert

7-Sep-09 22:34

I answered your question yesterday:
http://www.codeproject.com/Messages/3188266/Re-Strings-in-EXE.aspx[^]

Which part did you not understand?

Le@rner7-Sep-09 18:12

Le@rner

7-Sep-09 18:12

Hi all,

I am trying to handle keyboard strokes. For handling ctrl+c i have written this piece of code in my PreTranslateMsg function

BOOL CKeyboardStroke::PreTranslateMessage(MSG* pMsg) 
{
	 switch(pMsg->message) 
	 {   
	  case WM_KEYDOWN: 
		  {
			  if(GetKeyState(VK_CONTROL) && (pMsg->wParam == 0x43))
			  {
                                  CTest obj;
                                  obj.DoModal();
			  }
			  if(GetKeyState(VK_CONTROL) && (pMsg->wParam == 0x56))
			  {
				  AfxMessageBox(_T("ctrl V"));
			  }
		 }
	  }
	
	return CDialog::PreTranslateMessage(pMsg);
}

But my problem is when i press ctrl+c dialog box is opened and when i close it my application crashes.

Can anybody help me in this.

Thanks in advance

To accomplish great things, we must not only act, but also dream;
not only plan, but also believe.

Re: Closing of dialog box crashes application

theCPkid7-Sep-09 18:31

theCPkid

7-Sep-09 18:31

DoModal blocks the application at that point. It's not wise to block the application inside PreTranslateMsg. Try showing the dialog box in OnKeyDown handler or may be try this

if(GetKeyState(VK_CONTROL) && (pMsg->wParam == 0x43))
{
                    CTest obj;
                    obj.DoModal();
                    return TRUE; // this message need not be dispatched.
}

Re: Closing of dialog box crashes application

Le@rner7-Sep-09 18:34

Le@rner

7-Sep-09 18:34

thanku it worked

To accomplish great things, we must not only act, but also dream;
not only plan, but also believe.

Set the text of spincontrol( Updown control) using sendmessage

Bedke7-Sep-09 18:07

Bedke

7-Sep-09 18:07

Hi,

I am trying to automate the setting of text for a spincontrol through
a c++ program. The spinControl is in a different application.
The scenario is as follows:

There is an application which pops up a dialog box
which contains a Spincontrol. I want to set the text of
the spincontrol.

Input available: The Dialog box name and the control specifier of
the spincontrol.

Please colud someone help me.

Thanks in advance for any help.

Re: Set the text of spincontrol( Updown control) using sendmessage

Selvam R8-Sep-09 0:20

Selvam R

8-Sep-09 0:20

If you are using same application, you can access the object.

The spinControl is in a different application.

But, if you are using different application, you can use RPC mechanism for update values.

http://msdn.microsoft.com/en-us/library/aa511491.aspx[^]

Thanks and Regards,
Selvam,
http://www.wincpp.com

Re: Set the text of spincontrol( Updown control) using sendmessage

Bedke8-Sep-09 0:25

Bedke

8-Sep-09 0:25

Thanks for the reply..

I am writing a c++ program to automatically set the value of a spin control..

I have used UDM_SETPOS message in the SendMessage.
It is not able to set the value that i try to pass..

Any help will do.

SetWindowPos API doubt

theCPkid7-Sep-09 15:47

theCPkid

7-Sep-09 15:47

From SetWindowPos documentation,
hWndInsertAfter
[in] Handle to the window that precedes the positioned window in the Z order.

I have a doubt. the window that 'precedes' the position window is on top of it or below it?
My understanding is that hWndInsertAfter is the window immediately on top of positioned window but I am feeling suspicious. Sniff | :^)

Re: SetWindowPos API doubt

«_Superman_»7-Sep-09 16:01

«_Superman_»

7-Sep-09 16:01

I believe hWndInsertAfter will be just below hWnd. Haven't tried this myself.

«_Superman_»
I love work. It gives me something to do between weekends.

Overloading cast & assignment not enough for ==?

dplong7-Sep-09 11:22

Re: Overloading cast & assignment not enough for ==?

7-Sep-09 11:22

I wrote a generic template-based identifier class but am getting compilation errors with the is-equal operator. Anybody know how to fix this? The following code is a distillation of the problem. I get compilation errors for the conditional expressions within the assert()s. The error text in the comments is paraphrased from Visual 2008 C++ Express. I don't get these errors when the core type and the literal are an integral type, e.g., int. I assume this is due to implicit integral conversions.

#include <iostream>
#include <assert.h>

using namespace std;

class Name
{
public:
	Name(const string t_) : t(t_) { }
	Name() { }
	Name(const Name & t_) : t(t_.t) { }
	Name & operator=(const string & rhs) { t = rhs; return *this; }
	operator const string & () const { return t; }
	operator string & () { return t; }
private:
	string t;
};

int main()
{
	Name n1 = "bananas", n2 = "bananas";
	assert(n1 == n2);	// Couldn't deduce template arg for string from Name
	assert(n1 == "bananas");	// No operator found for LH operand of type Name
}

I'm thinking I need to overload the == operator. I tried that but ran into even more problems.

FWIW, my identifier class is similar to BOOST_STRONG_TYPEDEF() except that I want to be able to use the core type (possibly with implicit conversion) as an initializer to the derived type and as an argument to a derived-type parameter. I also want to use the derived type as an initializer to the core type. Here's an example of that:

BOOST_STRONG_TYPEDEF(string, S)
void f(S s) { }
int main() { S s = "abc"; f("def"); string str = s; }

Thanks!

CPallini7-Sep-09 11:54

Re: Overloading cast & assignment not enough for ==?

7-Sep-09 11:54

dplong wrote:
I'm thinking I need to overload the == operator. I tried that but ran into even more problems.

Well I think you need. BTW what are the problems?
Smile | :)

dplong7-Sep-09 12:30

Re: Overloading cast & assignment not enough for ==?

7-Sep-09 12:30

Oh, sorry:

"I get compilation errors for the conditional expressions within the assert()s. The error text in the comments is paraphrased from Visual 2008 C++ Express."

Basically, how do I get rid of those errors? I would like to be able to

1. compare two instances of my Name class for equality and

2. compare an instance of Name with an instance of its core type, string.

Like pointers, I only need to cast, assign, and compare for equality/inequality. For example, it doesn't make sense to add identifiers, like adding GUIDs.

Stuart Dootson7-Sep-09 14:41

Stuart Dootson

7-Sep-09 14:41

Think you'll find it useful to add a Name constructor that takes a const char*. Reason is that C++ won't do 2 implicit conversions to get a function/operator to match - the 2 implicit conversions in this case being const char* -> string -> Name. That also permits operator== (which you will need to define - it's not one of the standard compiler provided operators) between a Name and a string literal:

#include <iostream>
#include <assert.h>

using namespace std;

class Name
{
public:
	Name(const char* t_) : t(t_) { }
	Name(const string& t_) : t(t_) { }
	Name() { }
	Name(const Name & t_) : t(t_.t) { }
	Name & operator=(const string & rhs) { t = rhs; return *this; }
	operator const string & () const { return t; }
	operator string & () { return t; }
private:
	string t;
};
bool operator==(const Name& left, const Name& right) { return string(left)==string(right); }

int main()
{
	Name n1 = "bananas", n2 = "bananas";
	assert(n1 == n2);	// Couldn't deduce template arg for string from Name
	assert(n1 == "bananas");	// No operator found for LH operand of type Name
} 

<div class="ForumSig">Java, Basic, who cares - it's all a bunch of tree-hugging hippy cr*p</div>

Re: Overloading cast & assignment not enough for ==? [modified]

dplong7-Sep-09 18:39

Why do functions in the C library have short names?

7-Sep-09 18:39

Thanks a bunch, Stuart. I realized I had a few more situations to take into consideration, so this is the class now. It works like a charm. Thumbs Up | :thumbsup:

#include <string>
#include <assert.h>

using namespace std;

class Name
{
public:
	Name() { }
	Name(const string & t_) : t(t_) { }
	Name(const char * t_) : t(t_) { }
	Name & operator=(const string & rhs) { t = rhs; return *this; }
	Name & operator=(const char * rhs) { t = rhs; return *this; }
	friend bool operator==(const Name & lhs, const Name & rhs) { return lhs.t == rhs.t; }
	operator const string & () const { return t; }
	operator string & () { return t; }
private:
	string t;
};

int main()
{
	char arr[] = "bananas";
	char *arrP = arr;
	string s = "oranges";
	Name nn1 = s;
	Name n0 = string("apples");
	n0 = s;
	n0 = arr;
	n0 = arrP;
	nn1 = n0;
	Name nn2 = Name(nn1);
	Name n1 = "bananas", n2 = "bananas";
	assert(n1 == n2);
	assert(n1 == string("bananas"));
	assert(n1 == arr);
	assert(n1 == arrP);
	assert(n1 == "bananas");
}

This solution creates another problem for me, though. I was using the following template so that this behavior could be defined for any class, e.g., int, unsigned, and string:

template <class T, class D> class IdTemplate {
public:
	IdTemplate() { }
	IdTemplate(const T t_) : t(t_) { }
	IdTemplate & operator=(const T & rhs) { t = rhs; return *this; }
	friend bool operator==(const IdTemplate & lhs, const IdTemplate & rhs) { return lhs.t == rhs.t; }
	operator T & () { return t; }
	operator const T & () const { return t; }
private:
	T t;
};

However, the doubling up of the constructor and assignment operator for both string and char * makes this rather difficult because, for example, int doesn't have to consider a "shadow" type like char *. Any ideas on how to generalize the solution so that it may be represented with a template?

modified on Tuesday, September 8, 2009 1:05 AM

0x3c07-Sep-09 10:58

0x3c0

7-Sep-09 10:58

This is probably a really simple question, but I can't get my head around it. The C library that is linked with most applications uses functions like memcpy, strcat and memset. These names all seem very counter-intuitive, in comparison to CopyMemory, ConcatenateStrings and SetMemory. Likewise for calloc when compared to AllocateCleanMemory. Why is this?

My first thought was that this preserved stack space, but then I realised that the stack holds addresses, instead of method names. The only other possibility that I can think of is that C programmers dislike excessive typing, and so prefer shorter method names. Is this the reason why, or is there a technical constraint on method name length?

OSDev

Re: Why do functions in the C library have short names?

CPallini7-Sep-09 11:13

Re: Why do functions in the C library have short names?

7-Sep-09 11:13

Computafreak wrote:
The only other possibility that I can think of is that C programmers dislike excessive typing

That's true.

Computafreak wrote:
Is this the reason why, or is there a technical constraint on method name length?

Well, the linker deals also with function (methods have no place in C programmer's mind) names.

Another reason maybe historical: when the C library was firstly developed, Microsoft wasn't around... (More seriously there wasn't a plethora of functions to remember and low risk of name collisions, so, I suppose, using short names was reasonable).

BTW: C library functions have too long names for Klingon Developers.
Smile | :)

dplong7-Sep-09 11:32