C / C++ / MFC Discussion Boards

Re: Can someone (briefly) explain ON_UPDATE_COMMAND_UI?

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

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.

Re: Using array of string values

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.

Re: Using array of string values

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.

Re: Using array of string values

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.

"One man's wage rise is another man's price increase." - Harold Wilson

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Re: Using array of string values

CPallini13-Jun-13 6:45

CPallini

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.

Re: Using array of string values

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.

How to use user defined type in other function.

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

CPallini

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.

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

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

CPallini

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.

Capturing mouse input outside a dialog

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.

Re: Capturing mouse input outside a dialog

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.

Re: Capturing mouse input outside a dialog

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.

Re: Capturing mouse input outside a dialog

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.)

Re: Capturing mouse input outside a dialog

Erudite_Eric13-Jun-13 1:15

Erudite_Eric

13-Jun-13 1:15

Take a look at windows hooks.

==============================

Nothing to say.

Re: Capturing mouse input outside a dialog

thanh_bkhn13-Jun-13 16:57

thanh_bkhn

13-Jun-13 16:57

May be you just want to capture the mouse position, and you have no problem in finding the colour, then you can set a new Timer, then in the OnTimer function, you may try GetCursorPos() to retrieve the mouse's position.
If you want to capture other mouse's action like mouse click... then take a look at global hook, as described in this Mouse and KeyBoard Hooking utility with VC++[^]

CToolTipCtrl with TTF_TRACK Flag won't disappear, SetDelayTime doesn't work?

Falconapollo12-Jun-13 0:34

Falconapollo

12-Jun-13 0:34

I found if set TTF_TRACK flag to CTooltipCtrl, SetDelayTime doesn't work anymore, so the tooltip won't disappear automatically. I want to show the tooltip just below specified control, and expect it to disappear after a few seconds(the time can set with SetDelayTime). Anybody can help me?

Here is my steps to construct tool tip:1. Add member variable
CToolTipCtrl m_tooltip;
2. override PreTranslateMessage
BOOL CPF_GetSetNameDlg::PreTranslateMessage( MSG* pMsg )
{
switch (pMsg->message)
{
case WM_KEYDOWN:
case WM_SYSKEYDOWN:
case WM_LBUTTONDOWN:
case WM_RBUTTONDOWN:
case WM_MBUTTONDOWN:
case WM_LBUTTONUP:
case WM_RBUTTONUP:
case WM_MBUTTONUP:
case WM_MOUSEMOVE:
m_tooltip.RelayEvent(pMsg);
break;
}

return CDialog::PreTranslateMessage(pMsg);
}
3. OnInitialDialog
BOOL CPF_GetSetNameDlg::OnInitDialog()
{
CDialog::OnInitDialog();

//tooltip
EnableToolTips();
m_tooltip.Create(this , WS_POPUP | TTS_NOPREFIX | TTS_BALLOON);

m_tooltip.SetDelayTime(TTDT_INITIAL, 0);
m_tooltip.SetDelayTime(TTDT_AUTOPOP, 30000);
m_tooltip.SetDelayTime(TTDT_RESHOW, 30000);
m_tooltip.AddTool(GetDlgItem(IDC_SETNAME), _T(""));

m_tooltip.SetMaxTipWidth(600);
}
4. Control to show tool tip
if(bShow)
{
m_tooltip.UpdateTipText(_T("Hello, money!"), pWnd);
CToolInfo sTinfo;
m_tooltip.GetToolInfo(sTinfo, pWnd);
sTinfo.uFlags = TTF_TRACK;
m_tooltip.SetToolInfo(&sTinfo);

CRect rect;
pWnd->GetWindowRect(rect);
m_tooltip.SendMessage(TTM_TRACKPOSITION, 0, (LPARAM)MAKELONG(rect.left, rect.bottom));
m_tooltip.SendMessage(TTM_TRACKACTIVATE, TRUE, (LPARAM)&sTinfo );
}

LoadImage error

_Flaviu11-Jun-13 22:04

_Flaviu

11-Jun-13 22:04

I have this code:

C++

if(m_Bitmap.GetSafeHandle())
    m_Bitmap.DeleteObject();
HBITMAP hBitmap = (HBITMAP)::LoadImage(NULL, lpszPathName, IMAGE_BITMAP, 0, 0, LR_LOADFROMFILE | LR_CREATEDIBSECTION);
if(NULL == hBitmap)
{
    CString sMessage;
    const DWORD dwError = ::GetLastError();
    sMessage.Format(_T("Failed to load '%s' file. Reason: %s\n"), lpszPathName, GetErrorString(dwError));
    AfxMessageBox(sMessage, NULL, MB_ICONERROR);
    return FALSE;
}
m_Bitmap.Attach(hBitmap);

and work ok, but on the big bitmaps, I get:

C++

Not enough server storage is available to process this command

ok, I read this one[^], and I modified the "IRPStackSize" value to 0x19 (25 decimal), not working ... hoe can I get rid of this error ?

modified 12-Jun-13 4:37am.

Re: LoadImage error

Jochen Arndt11-Jun-13 22:58

Jochen Arndt

11-Jun-13 22:58

Is it really that error message and not the code 8 ERROR_NOT_ENOUGH_MEMORY message 'Not enough storage is available to process this command'?

You might google for 'loadimage ERROR_NOT_ENOUGH_MEMORY'. Reading some of the results, it seems that removing the LR_CREATEDIBSECTION flag might solve the problem. If you need a DIBSECTION bitmap and loading the image as DDB succeeds, you might try the CopyImage()[^] function afterwards to convert the loaded DDB.

Re: LoadImage error

_Flaviu11-Jun-13 23:24

_Flaviu

11-Jun-13 23:24

I had removed LR_CREATEDIBSECTION flag from LoadImage function, and I had the same error ... Frown | :(

Re: LoadImage error

Jochen Arndt11-Jun-13 23:38

Jochen Arndt

11-Jun-13 23:38

How big is your image? If you read some of the Google results, you will find that others had similar problems and solved it by using other methods to load images from files (e.g. the MFC CImage class that uses Gdiplus::Bitmap). Check also if your image is valid by loading it with any painting program. Also check that the image is not RLE compressed.

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