C / C++ / MFC

18-Apr-11 21:03

HI Guys,

I am using visual studio 2010 and I need to change the Mainframe icon at runtime based on my requirement so I have defined a macro _CHANGEICO. If this macro is defined I need to use some different icon and so I modified the .rc file accordingly and saved. Now If add any string or any new item to the resource all my macro declaration is deleted from the .rc file.

For example I have tried the following i.e. modified the resource file like this

#if defined(_CHANGEICO)
IDR_MAINFRAME ICON "res\\Orbit.ico"
#else
IDR_MAINFRAME ICON "res\\Sun.ico"
#endif

(OR)

#ifdef _CHANGEICO
IDR_MAINFRAME ICON "res\\Orbit.ico"
#else
IDR_MAINFRAME ICON "res\\Sun.ico"
#endif

After the above changes,I have added string to resource from visual studio, the .rc file is getting modified automatically like this

IDR_MAINFRAME ICON "res\\Sun.ico"

Can any one please help me in solving this issue, My changes should not be altered by the visual studio.

Niklas L18-Apr-11 22:04

Niklas L

18-Apr-11 22:04

You should not modify the .rc file by hand, since it's content will be overwritten whenever you edit a resource in the resource editor. You should have a file named *.rc2 which the environment will not touch. Make your edits there. (I think this file is included as the last statement in your .rc file.)

Also, this will not change the icon at runtime, but at compile time.

home

వేంకటనారాయణ(venkatmakam)18-Apr-11 23:32

వేంకటనారాయణ(venkatmakam)

18-Apr-11 23:32

Yes you are right,
and g_satish Check this link for sample example,
http://stackoverflow.com/questions/637900/how-to-conditionally-compile-vc6-resources[^]

g_satish19-Apr-11 0:03

19-Apr-11 0:03

I understood what you have said, I tried the same way the compiler is throwing errors like "res\IMAPP.rc2(75): fatal error RC1004: unexpected end of file found". Could you please give me a sample so that I can use it or instructions need to be followed for achieving this. Thanking u a lot...

Niklas L19-Apr-11 0:33

Niklas L

19-Apr-11 0:33

#ifdef _CHANGEICO
IDR_MAINFRAME ICON "res\\Orbit.ico"
#else
IDR_MAINFRAME ICON "res\\Sun.ico"
#endif

works just fine here. Make sure your #ifdef is properly closed by an #endif, which is the only reason I can think of creating your problem.

home

g_satish19-Apr-11 0:42

19-Apr-11 0:42

Thanks a lot ..it is working perfectly fine now..

David Crow19-Apr-11 7:22

David Crow

19-Apr-11 7:22

I'm not sure how your "I need to change the Mainframe icon at runtime" requirement is being met. Confused | :confused:

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g_satish19-Apr-11 19:12

19-Apr-11 19:12

I am sorry for mentioning as changing the icon at runtime in the question posted earlier, actually I need to change Icon at compile time. For changing it at compile time everyone has helped me to achieve it and it's been achieved.

వేంకటనారాయణ(venkatmakam)19-Apr-11 0:33

వేంకటనారాయణ(venkatmakam)

19-Apr-11 0:33

Syntax:

/////////////////////////////////////////////////////////////////////////////
// Add manually edited resources here...
#if defined _CHANGEICO
    IDR_MAINFRAME ICON "res\\icon1.ico"
#else
    IDR_MAINFRAME ICON "res\\icon2.ico"
#endif
/////////////////////////////////////////////////////////////////////////////

And You have to remove IDR_MAINFRAME From the .rc file

Duplicates in list

sadas232341s18-Apr-11 8:28

18-Apr-11 8:28

How to show only unique elements from this double linked list using UniqueList function? I made something, but it removes only the first...

<pre>
#include "iostream"

using namespace std;

void Add(int n);
void UniqueList();

struct Elem
{
int key;
Elem *prev;
Elem *next;
} *start;

int main()
{
int num;

while(cin >> num)
{
Add(num);
}

cout << endl;

UniqueList();

return 0;
}

void Add(int n)
{
Elem *p = start;
start = new Elem;

start->key = n;
start->next = p;
start->prev = NULL;
}

void UniqueList()
{
Elem *p = start;

if(NULL != start) cout << "The list is:" << endl;
else cout << "Empty list.";

while(NULL != p)
{ if(p->prev != p->next)
cout << p->key << endl;

p = p->next;
}
}
</pre>

C^hris L^osinger18-Apr-11 9:18

18-Apr-11 9:18

one problem is that you're never setting the 'prev' members of the added items to anything but NULL. if you have a double-linked list, you need to do something like this:

void Add(int n)
{
     Elem *p = start;
     start = new Elem;

     start->key = n;
     start->next = p;
     start->prev = NULL;

     p->prev=start;
}

but that will probably blow up the first time through, since start itself hasn't been initialized, and *start is never allocated.

sadas232341s18-Apr-11 9:20

18-Apr-11 9:20

and what about the other main problem with the duplicates?

C^hris L^osinger18-Apr-11 9:27

18-Apr-11 9:27

i'm going to guess that that's probably a side effect of:
a) not setting prev to anything but NULL and
b) not initializing 'start' the first time around.

and, maybe i don't understand the task, but why are you doing this:

if(p->prev != p->next)

why compare prev and next pointers ? and why compare prev and next and not p itself:

if(p->key != p->next->key)

sadas232341s18-Apr-11 9:29

18-Apr-11 9:29

I fixed the prev problem. "if(p->prev != p->next)" is a shot in the dark. Any ideas how to show only uniques Smile | :)

C^hris L^osinger18-Apr-11 9:38

18-Apr-11 9:38

you're on the right track. but the key thing that's missing is that the list needs to be sorted before you can be guaranteed that duplicates will show up in p and p->next.

duplicates, but p, p->next will never be the same: 1,4,3,5,3
this will work: 1,3,3,4,5

sadas232341s18-Apr-11 9:39

18-Apr-11 9:39

it's getting messy. How to sort a list??? (Doubly linked)

Luc Pattyn18-Apr-11 9:53

Luc Pattyn

18-Apr-11 9:53

You do not need to actually sort the list, since that would mean you first compare a lot of them and move around some nodes, then remove some (the duplicates). That is too much effort for what is needed.

What you need to do is compare a lot and remove, but never move. In pseudo-code (always solve an algorithmic problem in pseudo-code first):

foreach(Node n1) {
    foreach (Node n2 before n1) {
        if (n2.value==n1.value) {
            remove(n1);
            break;
        }
    }
}

PS: and that could be done on a single-linked list as well, as both loops are enumerating from the start and never need to go backward.

Luc Pattyn [Forum Guidelines] [My Articles] Nil Volentibus Arduum

Please use <PRE> tags for code snippets, they preserve indentation, improve readability, and make me actually look at the code.

sadas232341s18-Apr-11 9:58

18-Apr-11 9:58

i did not understand anything you said. And whats that code C++?

C^hris L^osinger18-Apr-11 10:02

18-Apr-11 10:02

if you don't want to sort:

for each node, Cur
  for each node, Temp
    if Temp!=Cur
      if Temp.value==Cur.value, duplicate
    Temp=Temp.next
  Cur=Cur.next

basically, for each node, you compare its value to every other node. it's inefficient, but it will work.

you can also sort your list when you add:
1. walk the list, find the first node with a value greater than the new value. this is 'Cur'
2. change the next pointer of Cur->prev to point to your new node.
3. set your new node's prev to Cur->prev. now you're all linked in the prev direction.
4. change the prev pointer of Cur to point to your new node.
5. set your new node's cur to point to Cur. now you're all linked in the next direction.

that way, the list is always sorted, and you can just walk it, looking for duplicates.

sadas232341s18-Apr-11 10:13

18-Apr-11 10:13

OK, I decided to sort the list, but can you tell me why is not working well?

David Crow18-Apr-11 18:02

David Crow

18-Apr-11 18:02

TCPMem wrote:
How to sort a list???

Insert the items in their "sorted" position within the list.

sadas232341s18-Apr-11 9:54