C / C++ / MFC

Re: Can someone (briefly) explain ON_UPDATE_COMMAND_UI?

13-Jun-13 6:53

Some insight here: "When Update Handlers Are Called"[^].

Veni, vidi, vici.

chaau13-Jun-13 18:38

chaau

13-Jun-13 18:38

If the logic that decides if the buttons should be enabled or disabled is too complicated it is advised (do not ask me to find who advised it, I just remember it somehow) that you do not use this method. You could always use CToolBarCtrl::EnableButton() for this and control it from within other parts of the program

Re: Can someone (briefly) explain ON_UPDATE_COMMAND_UI?

Iain Clarke, Warrior Programmer17-Jun-13 0:09

Iain Clarke, Warrior Programmer

17-Jun-13 0:09

One place that can fire off updating is the internal OnIdle. This is a fake message handler, called from the MFC message loop. So, you'll get updates a lot, but only when the message queue has "calmed down". So, if you get it a lot, it's because you don't have a lot else going on.

Iain.

I am one of "those foreigners coming over here and stealing our jobs". Yay me!

Using array of string values

Donguy197613-Jun-13 3:40

Donguy1976

13-Jun-13 3:40

Hello there

I am working on a C++ MFC app that has a user login option and the software will store upto
15 passwords used by a user.

Now i want to store each password used by a user in a string array and make sure that the user
doesn't use an old password when updating the password.

i.e., password once used cannot be re-used and an existing password will expire after a set number of days.

The question is what kind of collection class i need to use for efficient management of old passwords?
CArray?CList? CString array?

Any sample code will help.

Thanks in advance.

Simon Langdon13-Jun-13 4:14

Simon Langdon

13-Jun-13 4:14

It sounds like a trivial issue, use whichever types you're comfortable with. STL vectors and CStringArrays both leap to mind; do you need to save this data somehow? CStringArrays support CArchive but you may want to think about encryption or some other safety feature.

jeron113-Jun-13 4:16

jeron1

13-Jun-13 4:16

If you're only storing CStrings then CStringArray[^] would be a good choice. If you're storing something else, one of the other collections probably would be more appropriate, here[^] are some examples of thier usage, there are lots of others on the web. here[^] is a link that should help you to decide which collection might be best.

David Crow13-Jun-13 4:19

David Crow

13-Jun-13 4:19

Donguy1976 wrote:

The question is what kind of collection class i need to use for efficient management of old passwords?

Since you are only dealing with 15, and only searching the collection when the user is logging in (e.g., once per day), it likely does not matter the data structure you use.

CPallini13-Jun-13 6:45

13-Jun-13 6:45

If you are happy with MFC containers then CStringArray[^] is fine.
As side (though important) note, have a look at out Original's tip: "Password Storage: How to do it."[^].

Veni, vidi, vici.

How to use user defined type in other function.

Freak3014-Jun-13 0:43

Freak30

14-Jun-13 0:43

Personally I would use a vector, add a new password at the end when needed and remove the first one when size() becomes larger than 15. The scurity issues were already mentioned in the otherreplies.

Manoj739012-Jun-13 19:44

Manoj7390

12-Jun-13 19:44

Hi, I have written a code in C++ which works on the "POINT" user defined type i.e. POINT = (x,y).
I am giving input in int form, it is converting it into point might be using "template<int p="">". I am retrieving these point from another function which is a header file of mine.
Now the problem is, I am calling this function in NS-3 software/program, I am unable to convert this point form into integer.
* Can i return more than one value from a function, because point has two values i.e. X and Y.

Please help me out.

Re: How to use user defined type in other function.

Richard MacCutchan12-Jun-13 21:05

Richard MacCutchan

12-Jun-13 21:05

Assuming you mean the POINT structure[^], you could pass it back by pointer, or pass in a pointer or reference that the called function fills in.

Use the best guess

Re: How to use user defined type in other function.

Manoj739012-Jun-13 21:41

Manoj7390

12-Jun-13 21:41

Here is my some part of my code....

XML

int my_encrypt()

{

    typedef EllipticCurve<263> ec_t;

    ec_t   myEllipticCurve(1,1);

ec_t::Point P = myEllipticCurve[2];

cout << "some point P = " << P << ", 2P = " << (P+P) << "\n";

int a = irand(1,myEllipticCurve.Degree()-1);

ec_t::Point Pa = a*G; // public key

cout << "Alice' public key Pa = " << a << "*" << G << " = " << Pa << endl;

C#

ec_t::Point Pk = a*Pb; ec_t::ffe_t c1( m1*Pk.x() ); ec_t::ffe_t c2( m2*Pk.y() );

I need to return these three values (Pa, C1, C2) into my main function.

Re: How to use user defined type in other function.

Richard MacCutchan12-Jun-13 22:29

Richard MacCutchan

12-Jun-13 22:29

Sorry, but you lost me at typedef EllipticCurve<263> ec_t;.

Use the best guess

Re: How to use user defined type in other function.

CPallini12-Jun-13 23:26

Re: How to use user defined type in other function.

12-Jun-13 23:26

then change your function:

int my_encrypt(ec_t::Point * pPa, ec_t::ffe_t * pc1, ec_t::ffe_t * pc2 )
{
//...

 // 'return' the values
 *pPa = Pa;
 *pc1 = c1;
 *pc2 = c2;

 return 0; // or whatever is meaningful for you
}

You may as well use the approach suggested by Richard, that is embed Pa, c1, c2 into a struct and pass the pointer to such a struct to your function.

Veni, vidi, vici.

Manoj739013-Jun-13 23:54

Manoj7390

13-Jun-13 23:54

Hi.. i have used the structure to pass three different variable as shown below...
int main()
{
struct result t1;

t1 = my_encrypt();
cout << t1.pa << t1.c1 << t1.c2 <<;
}

struct result my_encrypt()
{
typedef EllipticCurve<263> ec_t;

struct result
{
ec_t::Point Pa;
ec_t::ffe_t c1;
ec_t::ffe_t c2;
}t;

ec_t::Point Pk = a*Pb;

ec_t::ffe_t t.c1( m1*Pk.x() );

ec_t::ffe_t t.c2( m2*Pk.y() );

return (t);
}

I am getting so many errors.. Please tell me anything wrong declaration here.
Can i declare that structure as global...

Re: How to use user defined type in other function.

CPallini14-Jun-13 0:42

Capturing mouse input outside a dialog

14-Jun-13 0:42

Quote:
int main()
{
struct result t1;

t1 = my_encrypt();

Should be:

int main()
  {
    struct result t1 = {0};

    my_encrypt(&t1);
    //..

Quote:
struct result my_encrypt()
{

should be:

int my_encrypt(struct result * pt1)
  {
    // ...

Please note, there are other (unrelated) errors in your code.

Veni, vidi, vici.

rbrunton12-Jun-13 7:19

rbrunton

12-Jun-13 7:19

I am trying to create a dialog MFC application that reads the cursor position anywhere on the screen, finds the colour of the pixel at that location and reports the information back to the dialog application.

I have tried SetCapture and I must be doing something wrong because the cursor location stops reporting as soon as the cursor leaves the client area of the dialog. I have also looked at the "Screen Color Picker" by Florin Vasilescu. That uses an OnTimer function that allows me to read the screen location, but does not report mouse actions (LBUTTONDOWN) so that I can read the pixel at the cursor location.

I have also tried using SetWindowsHookEx and defining the MouseProc (as described by Vesi in the CodeGuru article "Modal dialog and outside mouse control". That wasn't successful. If I use the WH_JOURNALRECORD hook ID as described there appears to be an indeterminate delay between any mouse (or keyboard) action and interaction with screen objects. If I use the WH_MOUSE no mouse actions are detected.

Could someone help me with how to either properly set SetCapture() or point me to where I might discover how to read mouse actions outside the dialog box? I'm happy to supply code, but at this point it's a bit of a mess since I've been trying everything.

Thanks for any help you may be able to provide. Much appreciated.

David Crow12-Jun-13 10:19

David Crow

12-Jun-13 10:19

rbrunton wrote:
I am trying to create a dialog MFC application that reads the cursor position anywhere on the screen, finds the colour of the pixel at that location and reports the information back to the dialog application.

This sounds like Pixie. I've used it a few times, and it does what I needed it to do.

rbrunton12-Jun-13 11:04

rbrunton

12-Jun-13 11:04

Thanks David,

I'll check it out as a tool, but I'm really looking to find out how to accomplish the task; essentially a programming learning experience.

rbrunton12-Jun-13 11:11

rbrunton

12-Jun-13 11:11

PS - Pixie doesn't seem to address the key problem. Instead of using a left-mouse click to grab the colour at the particular location, pixie require keyboard shortcuts - Ctrl+Alt+c to copy HTML, Ctrl_Alt_X for to bring up the standard windows color dialog and Ctrl+Alt+Z to display a larger background of the color at the cursor. I would like to accomplish the selection with the left-mouse click as that seems a little more "natural" in a windows environment and then have the result in the main dialog screen of the application to manipulate it into various formats (HEX, RGB, HTML, etc.)

Erudite_Eric13-Jun-13 1:15

Erudite_Eric

13-Jun-13 1:15

Take a look at windows hooks.

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Nothing to say.