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Did you put these statements in all of your *.h files :
#if !defined YOURFILENAME<br />
#define YOURFILENAME<br />
<br />
...<br />
...<br />
...<br />
<br />
#endif
Replace YOURFILENAME by something unique to every file.
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Those statements are set by default by Visual Studio in every class file. I tried also to create a dll file from Myheader, but even if i add that library to my project, the app doesn't recognize the functions of the library. Should I addd a .DEF file?
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Hello
You should not include Myheader.h in both the files. You can include the Myheader.h in CTwo.h and include CTwo.h in COne.h
I hope it would work...
Bye,
Sreekanth Muralidharan
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I've already tried this way, but the result was the same.
I solved the problem in another way.
Thanks to everyone
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Hello buddies,
I am designing a queue by a linked list for an application. I wrote the following code while it brought up an exception in the line marked here. Could you please help me out ?
#include <stdio.h><br />
#include <conio.h><br />
struct queuelist<br />
{<br />
int intData;<br />
int valid;<br />
struct queuelist* next;<br />
<br />
};<br />
struct queuelist *head, *tail;<br />
<br />
int AddToQueue(struct queuelist*,int);<br />
int RemoveFromQueue(struct queuelist*);<br />
int DeleteQueue(struct queuelist*);<br />
void DisplayQueue(struct queuelist*);<br />
void menu();<br />
void menu()<br />
{<br />
<br />
int option=0;<br />
struct queuelist* queue;<br />
int data;<br />
printf("Queue Manipulation Menu\n");<br />
printf("........................\n\n");<br />
printf("1. Add member to queue.\n");<br />
printf("2. Extract next member.\n");<br />
printf("3. Delete whole queue.\n");<br />
printf("4. Help\n");<br />
printf("5. Display queue contents.\n");<br />
printf("6. Quit.\n");<br />
scanf("%d",&option);<br />
switch(option)<br />
{<br />
case 1:<br />
printf("Adding to queue.\n");<br />
printf("Member: ");<br />
scanf("%d",&data);<br />
if(AddToQueue(queue,data)==-1)<br />
printf("Could not add..\n");<br />
else<br />
printf("Added..\n");<br />
menu();<br />
<br />
case 2:<br />
system("cls");<br />
printf("Extract next member.\n");<br />
RemoveFromQueue(queue);<br />
menu();<br />
<br />
<br />
case 3:<br />
DeleteQueue(queue);<br />
menu();<br />
<br />
case 4:<br />
printf("Under Construction.\n");<br />
menu();<br />
case 5:<br />
printf("Queue Contents.\n");<br />
DisplayQueue(queue);<br />
menu();<br />
case 6:<br />
exit(0);<br />
<br />
default:<br />
printf("Invalid Option..\n");<br />
<br />
}<br />
}<br />
<br />
void main()<br />
{<br />
system("cls");<br />
menu();<br />
getch();<br />
<br />
}<br />
<br />
int AddToQueue(struct queuelist** q, int data)<br />
{<br />
struct queuelist** temp;<br />
q = head;<br />
if(q == NULL)<br />
{<br />
printf("First member in queue.\n");<br />
temp = (struct queuelist**)malloc(sizeof(struct queuelist));<br />
if(*temp == NULL)<br />
{<br />
printf("Not enough memory. Stopping...\n");<br />
return -1;<br />
}<br />
else<br />
{<br />
(*temp)->intData = data;<br />
(*temp)->next=NULL;<br />
(*temp)->valid=1;<br />
<br />
(*q)->next = temp;<br />
head = *q;<br />
tail = *q;<br />
<br />
}<br />
<br />
<br />
}<br />
else<br />
{<br />
while((*q)->next!=NULL) (*q) = &(*q)->next;<br />
<br />
temp = (struct queuelist**)malloc(sizeof(struct queuelist));<br />
if((*temp) == NULL)<br />
{<br />
printf("Not enough memory. Quitting...\n");<br />
return -1;<br />
}<br />
else<br />
{<br />
(*temp)->intData = data;<br />
(*temp)->next=NULL;<br />
(*q)->next = *temp;<br />
(*q) = (*q)->next;<br />
(*q)->valid = 1;<br />
tail = *q;<br />
<br />
}<br />
<br />
<br />
}<br />
<br />
<br />
<br />
}<br />
<br />
<br />
void DisplayQueue(struct queuelist* queue)<br />
{<br />
system("cls");<br />
queue = head;<br />
if(queue == NULL || queue->valid != 1)<br />
{<br />
printf("Empty Queue");<br />
}<br />
else<br />
{<br />
while(queue != NULL)<br />
{<br />
printf("||%d|%x||->",queue->intData,queue->next);<br />
queue = queue->next;<br />
}<br />
<br />
}<br />
printf("\n");<br />
<br />
}<br />
<br />
int RemoveFromQueue(struct queuelist* queue)<br />
{<br />
<br />
struct queuelist* prev;<br />
struct queuelist* second;<br />
queue = head;<br />
if(queue->valid !=1)<br />
{<br />
printf("Queue Exhausted. No members.\n");<br />
return -1;<br />
}<br />
else<br />
{<br />
queue = head;<br />
prev = queue;<br />
queue = queue->next;<br />
second = queue;<br />
head = queue;<br />
printf("Popped off : %d at %x\n",prev->intData, prev->next);<br />
prev->next = NULL;<br />
free(prev);<br />
}<br />
<br />
<br />
<br />
}<br />
int DeleteQueue(struct queuelist* queue)<br />
{<br />
struct queuelist* prev;<br />
queue = head;<br />
while(queue!=NULL)<br />
{<br />
prev = queue;<br />
queue = queue->next;<br />
queue->valid=0;<br />
free(prev);<br />
}<br />
<br />
<br />
}
Bye....
 Sreekanth Muralidharan
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Beside writing code for learning new things, I would never ever implement my own linked list or so when there are powerful, well-tested and broadly used collection classes like the STL [^].
--
Affordable Windows-based CMS: www.zeta-producer.de/enu
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Hello friend,
I would not prefer using STL for my small application. If you would refer to the code and find out the bug, it would be of great help to me.
Regards,
Sreekanth Muralidharan
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Firstly, I would offer the same advice, don't write your own linked lists or collections etc, use STL or the MFC CList etc.
The problem in your code appears to be a confusion in the pointers, and the code is littered with such problems, eg in AddToQueue(), you have set temp to be of type struct questlist **, but your call to malloc (btw why are you not using new???), will create a pointer to a single queuelist (i.e. (struct queuelist *)). So you should change the code to something like
struct queuelist *temp = NULL;
.............
temp = (struct queuelist *)malloc( sizeof(struct queuelist) );
if ( temp == NULL )
{
// Not enough memory etc
}
else
{
temp->intData = data;
temp->next=NULL;
temp->valid=1;
*q = temp;
}
The function call to AddToQueue() in your main part should read AddToQueue( &queue ) else the wrong type is being passed to the function.
I must admit that I am surprised that your compiler did not generate warning messages with your code? I think that you would be best of revisiting all of your code, and checking all your pointers and paraeters. Remember that malloc will only return a pointer to a section of memory that you have allocated.
Better still, use STL or perhaps the MFC CList template.
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Hello
Thanks to all who took their time to go through my bugful code.
Regards,
Sreekanth Muralidharan
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2) You are using uninitialised variables (ONE CAUSE OF EXCEPTION).
3) You are passing uneeded queue pointer arguments. Every function can see the global head variable and since you are only using one list you do not need to pass pointer arround.
4) You should be using a loop in the menu() function, instead of recursion, to get usere input.
5) You have variable that are not needed or actualy used.
6) You can use a temporary queue pointer in the function that need access to the queue.
I tried to point out as many problems as I could in your current code (without rewring it).
#include <process.h>
#include <stdio.h>
#include <stdlib.h>
struct queuelist
{
int intData;
int valid;
struct queuelist* next;
};
struct queuelist *head, *tail;
int AddToQueue(struct queuelist*,int);
void menu()
{
int option=0;
struct queuelist* queue;
int data;
printf("Queue Manipulation Menu\n");
switch(option)
{
case 1:
if(AddToQueue(queue,data)==-1)
menu();
case 6:
exit(0);
default:
printf("Invalid Option..\n");
}
}
void main()
{ }
int AddToQueue(struct queuelist** q, int data)
{
struct queuelist** temp;
q = head;
if(q == NULL)
{ }
else
{ }
}
void DisplayQueue(struct queuelist* queue)
{
system("cls");
queue = head;
}
int RemoveFromQueue(struct queuelist* queue)
{
struct queuelist* prev;
struct queuelist* second;
queue = head;
if(queue->valid !=1)
{ }
else
{
queue = head;
prev = queue;
queue = queue->next;
second = queue;
head = queue;
printf("Popped off : %d at %x\n",prev->intData, prev->next);
prev->next = NULL;
free(prev);
}
}
int DeleteQueue(struct queuelist* queue)
{
struct queuelist* prev;
queue = head;
while(queue!=NULL)
{ }
}
Good luck and keep trying!
INTP
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I cleared the above problems with the following updates to my original code:
#include <stdio.h><br />
#include <conio.h><br />
#include <process.h><br />
#include <malloc.h><br />
<br />
struct queuelist<br />
{<br />
int intData;<br />
int valid;<br />
struct queuelist* next;<br />
<br />
};<br />
struct queuelist *head, *tail;<br />
<br />
int AddToQueue(struct queuelist*,int);<br />
int RemoveFromQueue(struct queuelist*);<br />
int DeleteQueue(struct queuelist*);<br />
void DisplayQueue(struct queuelist*);<br />
void menu();<br />
struct queuelist* queue=NULL;<br />
<br />
void menu()<br />
{<br />
<br />
int option=0;<br />
<br />
int data=0;<br />
printf("Queue Manipulation Menu\n");<br />
printf("........................\n\n");<br />
printf("1. Add member to queue.\n");<br />
printf("2. Extract next member.\n");<br />
printf("3. Delete whole queue.\n");<br />
printf("4. Help\n");<br />
printf("5. Display queue contents.\n");<br />
printf("6. Quit.\n");<br />
scanf("%d",&option);<br />
switch(option)<br />
{<br />
case 1:<br />
queue=head;<br />
printf("Adding to queue.\n");<br />
printf("Member: ");<br />
scanf("%d",&data);<br />
if(AddToQueue(queue,data)==-1)<br />
printf("Could not add..\n");<br />
else<br />
printf("Added..\n");<br />
break;<br />
<br />
case 2:<br />
system("cls");<br />
printf("Extract next member.\n");<br />
RemoveFromQueue(queue);<br />
break;<br />
<br />
case 3:<br />
DeleteQueue(queue);<br />
break;<br />
<br />
case 4:<br />
printf("Under Construction.\n");<br />
case 5:<br />
printf("Queue Contents.\n");<br />
DisplayQueue(queue);<br />
break;<br />
<br />
case 6:<br />
exit(0);<br />
<br />
default:<br />
printf("Invalid Option..\n");<br />
<br />
}<br />
}<br />
<br />
void main()<br />
{<br />
system("cls");<br />
while(1)<br />
menu();<br />
getch();<br />
<br />
}<br />
<br />
int AddToQueue(struct queuelist* q, int data)<br />
{<br />
struct queuelist* temp;<br />
q = head;<br />
if(q == NULL)<br />
{<br />
printf("First member in queue.\n");<br />
q = (struct queuelist*)malloc(sizeof(struct queuelist));<br />
if(q == NULL)<br />
{<br />
printf("Not enough memory. Stopping...\n");<br />
return -1;<br />
}<br />
else<br />
{<br />
q->intData = data;<br />
q->valid=1;<br />
q->next=NULL;<br />
head = q;<br />
tail = q;<br />
<br />
}<br />
<br />
<br />
}<br />
else<br />
{<br />
q=head;<br />
while(q->next!=NULL) q = q->next;<br />
<br />
temp = (struct queuelist*)malloc(sizeof(struct queuelist));<br />
if(temp == NULL)<br />
{<br />
printf("Not enough memory. Quitting...\n");<br />
return -1;<br />
}<br />
else<br />
{<br />
temp->intData = data;<br />
temp->next=NULL;<br />
q->next = temp;<br />
q = q->next;<br />
q->valid = 1;<br />
tail = q;<br />
<br />
}<br />
<br />
<br />
}<br />
<br />
<br />
return data;<br />
}<br />
<br />
<br />
void DisplayQueue(struct queuelist* queue)<br />
{<br />
system("cls");<br />
queue = head;<br />
if(queue == NULL || queue->valid != 1)<br />
{<br />
printf("Empty Queue");<br />
}<br />
else<br />
{<br />
while(queue != NULL)<br />
{<br />
printf("||%d|%x||->",queue->intData,queue->next);<br />
queue = queue->next;<br />
}<br />
<br />
}<br />
printf("\n");<br />
<br />
}<br />
<br />
int RemoveFromQueue(struct queuelist* queue)<br />
{<br />
<br />
struct queuelist* prev;<br />
struct queuelist* second;<br />
queue = head;<br />
if(queue->valid !=1 || queue==NULL)<br />
{<br />
printf("Queue Exhausted. No members.\n");<br />
return -1;<br />
}<br />
else<br />
{<br />
queue = head;<br />
prev = queue;<br />
queue = queue->next;<br />
second = queue;<br />
head = queue;<br />
printf("Popped off : %d at %x\n",prev->intData, prev->next);<br />
prev->next = NULL;<br />
free(prev);<br />
}<br />
<br />
return prev->intData;<br />
<br />
}<br />
int DeleteQueue(struct queuelist* queue)<br />
{<br />
struct queuelist* prev;<br />
queue = head;<br />
if(queue == NULL)<br />
return -1;<br />
while(queue!=NULL)<br />
{<br />
prev = queue;<br />
queue = queue->next;<br />
queue->valid=0;<br />
free(prev);<br />
}<br />
<br />
return 1;<br />
}
Tis now working perfectly. I will return with wrappers around this so that these could be included in a class.
Regards,
Sreekanth Muralidharan,;P
Software Consultant.
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Hello
See the code in C++ for linked list implementation of a queue.
<code> #include <iostream.h>
#include <stdlib.h>
#include <process.h>
#include <conio.h>
#include <dos.h>
struct queuelist
{
int intData;
int valid;
struct queuelist* next;
};
struct queuelist *head, *tail;
class CNode
{
private:
struct queuelist* queue;
public:
int AddToQueue(int);
int PopFromQueue();
int DeleteQueue();
void DisplayQueue();
};
void menu();
void menu()
{
textcolor(WHITE);
cout<<" Queue Manipulation Menu"<<endl;
cout<<"........................"<<endl<<endl;
cout<<"1. Add member to queue."<<endl;
cout<<"2. Extract next member."<<endl;
cout<<"3. Delete whole queue."<<endl;
cout<<"4. Help"<<endl;
cout<<"5. Display queue contents."<<endl;
cout<<"6. Quit."<<endl;
}
void main()
{
clrscr();
int data;
int option;
CNode node;
while(1)
{
menu();
cout<<"OPTION: ";
cin>>option;
cout<<endl;
switch(option)
{
case 1:
cout<<"Member: ";
cin>>data;
if(node.AddToQueue(data)==-1)
cout<<"Could not add.."<<endl;
else
cout<<"Added.."<<endl;
break;
case 2:
int pop=0;
clrscr();
cout<<"Extract next member."<<endl;
pop = node.PopFromQueue();
if(pop!=-1)
cout<<node.PopFromQueue();
break;
case 3:
clrscr();
node.DeleteQueue();
break;
case 4:
cout<<"Under Construction."<<endl;
break;
case 5:
clrscr();
cout<<"Queue Contents."<<endl;
node.DisplayQueue();
break;
case 6:
exit(0);
default:
textcolor(RED);
cout<<"Invalid Option.."<<endl;
break;
}
}
getch();
}
int CNode::AddToQueue(int data)
{
struct queuelist* q;
struct queuelist* temp;
q = head;
if(q == NULL)
{
cout<<"First member in queue."<<endl;
temp = (struct queuelist*)malloc(sizeof(struct queuelist));
if(temp == NULL)
{
textcolor(RED);
cout<<"Not enough memory. Stopping..."<<endl;
return -1;
}
else
{
temp->intData = data;
temp->next=NULL;
temp->valid=1;
q->next = temp;
head = temp;
tail = temp;
q = temp;
}
}
else
{
while(q->next!=NULL) q=q->next;
temp = (struct queuelist*)malloc(sizeof(struct queuelist));
if(temp == NULL)
{
textcolor(RED);
cout<<"Not enough memory. Quitting..."<<endl;
return -1;
}
else
{
temp->intData = data;
temp->next=NULL;
q->next = temp;
q = q->next;
q->valid = 1;
tail = q;
}
}
return 1;
}
void CNode::DisplayQueue()
{
struct queuelist* queue;
queue = head;
if(queue == NULL || queue->valid != 1)
{
textcolor(RED);
cout<<"Empty Queue";
}
else
{
while(queue != NULL)
{
if(queue->next!=0)
cout<<"||"<<queue->intData<<"|"<<queue->next;
else
cout<<"||"<<queue->intData<<"|NULL||->";
queue = queue->next;
}
}
cout<<endl;
}
int CNode::PopFromQueue()
{
int tempdat=0;
struct queuelist* queue;
struct queuelist* prev;
queue = head;
if(queue->valid !=1)
{
textcolor(RED);
cout<<"Queue Exhausted. No members."<<endl;
return -1;
}
else
{
queue = head;
prev = queue;
queue = queue->next;
head = queue;
}
tempdat = prev->intData;
prev->next=NULL;
free(prev);
return tempdat;
}
int CNode::DeleteQueue()
{
struct queuelist* prev;
queue = head;
while(queue!=NULL)
{
prev = queue;
queue = queue->next;
queue->valid=0;
free(prev);
}
return 1;
}</code>
Bye,
Sreekanth Muralidharan
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 Much better, but still shows confusion.
 Now you have C and C++ mixed all up together in a Frakeinstineon (the monster) kind of way.
You need to know a little more about C programing and for C++ programing I recommend the Bruce Eckel series of books, since he is good at explaning it. Also, Bruce Eckel has a web-site that has copies of his books in electronic form that you can download (recomend purchasing them though).
After reading you bio and seeing how well you did, I have decided to write my version and will send it to you (when finished).
Mean while:
1) queuelist is still a node.
2) CNode is not a node it represents the list.
3) The fuctions that require a return value do not return a success value.
4) The getch() function will never be reached, because you are still using exit() to exit from the program.
typedef struct tagNode
{
struct tagNode* pNext;
int intData;
} NODE;
static NODE* g_pHead;
int AddNode(int intData);
int DisplayList();
int DeleteNode();
void DeleteAll();
class CIntList
{
struct NODE
{
struct NODE* pNext;
int intData;
};
NODE* m_pHead;
public:
int AddNode(int intData);
int DisplayList();
int DeleteNode();
void DeleteAll();
CIntList() : m_pHead(NULL) {}
~CIntList() { DeleteAll(); }
};
Good Luck!
INTP
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I'm working with MFC42 (the one that came with VS6). Is there any way to gray out buttons in the toolbar which have a handler ?
I have got a base class for all my dialog boxes, which handles the messages. So every dialog box has got a function which handles the Toolbar messages altough the handler doesn't do anything useful. The users want the buttons with unuseful handlers grayed out, so i have to do this programmatically.
Any ideas ?
All the label says is that this stuff contains chemicals "... known to the State of California to cause cancer in rats and low-income test subjects."
Roger Wright
http://www.codeproject.com/lounge.asp?select=965687&exp=5&fr=1#xx965687xx
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Every ToolbUtton must have A ID .
via Using these Function you can disable them
let Button id you want to disable is ID_BUTTON1
then here is little piece of Code.
CButton *But=(CButton*)this->GetDlgItem(ID_BUTTON1);<br />
<br />
if(But)<br />
{<br />
But->EnableWindow(FALSE);<br />
}
-----------------------------
"I Think It Will Help"
-----------------------------
Alok Gupta
visit me at http://www.thisisalok.tk
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You should implement the <a href="http://msdn.microsoft.com/library/en-us/vclib/html/_mfc_on_update_command_ui.asp">ON_UPDATE_COMMAND_UI</a> [<a href="http://msdn.microsoft.com/library/en-us/vclib/html/_mfc_on_update_command_ui.asp" target="_blank" title="New Window">^</a>] handler for your button's control ID and then call pCmdUI->Enable( false ) in that handler.
--
Affordable Windows-based CMS: www.zeta-producer.de/enu
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I do create a CListCtrl (yes, really this is no voting joke! ) with the WS_BORDER style inside a control and later put it into a dialog box by code, too.
The problem is that the control that I create by hand has a 1 pixel black border on XP but not the 1 pixel blue border (i.e. the Windows XP themed border) when being dropped visually on a dialog box.
Question: Can anyone tell me how to acchieve the themed version when creating a control programatically?
Thanks!
--
Affordable Windows-based CMS: www.zeta-producer.de/enu
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Got it myself :
The Control does not have the WS_BORDER style but rather the extended WS_EX_CLIENTEDGE style. Then it looks correctly.
--
Affordable Windows-based CMS: www.zeta-producer.de/enu
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Hi guys ...
I have two questions for you:
1. How can i detect if SP1, or SP2 is installed on a machine(and if is the final release, not beta)
and is there any way to know if the OS is in "Safe Mode" ?
2. I have to install some files from my app, but they are protected by Windows File Protection. Is there any way
to install them? [w/o copying them from safe mode]
Thanks ...
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I this Can help you out
OSVERSIONINFO
The OSVERSIONINFO data structure contains operating system version information. The information includes major and minor version numbers, a build number, a platform identifier, and descriptive text about the operating system. This structure is used with the GetVersionEx function.
<br />
typedef struct _OSVERSIONINFO{ <br />
DWORD dwOSVersionInfoSize; <br />
DWORD dwMajorVersion; <br />
DWORD dwMinorVersion; <br />
DWORD dwBuildNumber; <br />
DWORD dwPlatformId; <br />
TCHAR szCSDVersion[ 128 ]; <br />
} OSVERSIONINFO;
AND
lAST pARAMETER
szCSDVersion
Windows NT/2000/XP: Contains a null-terminated string, such as "Service Pack 3", that indicates the latest Service Pack installed on the system. If no Service Pack has been installed, the string is empty.
Windows 95/98/Me: Contains a null-terminated string that indicates additional version information. For example, " C" indicates Windows 95 OSR2 and " A" indicates Windows 98 Second Edition
-----------------------------
"I Think It Will Help"
-----------------------------
Alok Gupta
visit me at http://www.thisisalok.tk
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Hi every body.
How i'am program same MSN Messenger when has user login.
a program stay in system tray popup dialog message same
MSN Messanger or Norton Antivirus
Thank you.
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My error!
First time!i choice Two.m_cbodata is Two.
Second time!i choice One.m_cbodata is Two.
When i choice ,my Combo Box data is not change.
I don't know what happen.
pls help me.
My code is following......
//MyView.h
public:
//{{AFX_DATA(CMyView)
CString m_cbodata;
//}}AFX_DATA
//MyView.cpp
void Click()
{
UpdateData(TRUE);
if (m_cbodata=="One")
{
AfxMessageBox("One");
}
if (m_cbodata=="Two")
{
AfxMessageBox("Two");
}
}
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i found my error!!!
i change following code!!!!
//MyView.cpp
if (0==m_ctrldevice.GetCurSel( ))
{
AfxMessageBox("One");
}
if (1==m_ctrldevice.GetCurSel( ))
{
AfxMessageBox("Two");
}
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how about this:
CString str;
str.Format("%d",m_ctrldevice.GetCurSel() + 1);
AfxMessageBox(str);
this will display a messagebox with "1","2", or whatever the cursel is.
If I write code in my sleep, does that make me brilliant, or just a lazy programmer?
My articles
www.stillwaterexpress.com
BlackDice - the programmer formerly known as bdiamond
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Hi !
I'm facing many problems (app crashs) when my app is compiled in release mode (problems I don't have in debug mode). I noticed that removing some const_cast improved the situation.
This makes me wonder : am I allowed to use const_cast ? How can I spot the situations where const_cast should be avoided ? If const_cast is dangerous, why is it provided ?
Thanks for your enlightment !
Jerome
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