C / C++ / MFC

Re: convert a CString to a char

29-May-02 7:15

use GetAt()

for example if CString temp="test"

out=temp.GetAt(3);

!! Put it in a if statement to prevent a asertation error:

if temp.GetLength()>2{ // e.g. 3
out=temp.GetAt(3);
}

Hope that helped.

An Expert is somone who has previously made ALL the Mistakes, I dream of this day. - Lucky

ed987129-May-02 7:17

ed9871

29-May-02 7:17

You can do it just like it was a char string.

CString m_sTest;
char c;

c = m_sTest[2];

You could also use the Mid function on the CString.

Ed

Re: convert a CString to a char

Martin Ziacek29-May-02 7:23

29-May-02 7:23

The Eclypse wrote:
Unless anyone know how to pick the 3rd character in on a CString

I think this could work:

CString str;

str = "123";

if (str[2] == '3') {
TRACE("Hey, you've got it!\n");
}

Read / Write Registry

Lucky the code machine29-May-02 7:08

29-May-02 7:08

Hiya,
Please halp me! I need some code to read & write registry keys in a particular place that already exists:

"HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings"

above is the location and then i need to write a new key & read a key. DWord and Edit. Is there a simple way to do this?

Thank you for your time. Smile | :)

An Expert is somone who has previously made ALL the Mistakes, I dream of this day. - Lucky

Martin Ziacek29-May-02 7:19

29-May-02 7:19

There is CRegKey class in the VC++ 6.0 installation somewhere, it is easy to use.

Lucky the code machine29-May-02 7:17

29-May-02 7:17

I dont understand (Sory) How do i get at / read that?

An Expert is somone who has previously made ALL the Mistakes, I dream of this day. - Lucky

Martin Ziacek29-May-02 7:28

29-May-02 7:28

This is declaration of that class:

class CRegKey
{
public:
CRegKey();
~CRegKey();

// Attributes
public:
operator HKEY() const;
HKEY m_hKey;

// Operations
public:
LONG SetValue(DWORD dwValue, LPCTSTR lpszValueName);
LONG QueryValue(DWORD& dwValue, LPCTSTR lpszValueName);
LONG QueryValue(LPTSTR szValue, LPCTSTR lpszValueName, DWORD* pdwCount);
LONG QueryValue(BYTE *pbValue, LPCTSTR lpszValueName, DWORD* pdwCount);
LONG SetValue(LPCTSTR lpszValue, LPCTSTR lpszValueName = NULL);
LONG SetValue(BYTE *pbValue, DWORD dwLength, LPCTSTR lpszValueName = NULL);

LONG SetKeyValue(LPCTSTR lpszKeyName, LPCTSTR lpszValue, LPCTSTR lpszValueName = NULL);
static LONG WINAPI SetValue(HKEY hKeyParent, LPCTSTR lpszKeyName, LPCTSTR lpszValue, LPCTSTR lpszValueName = NULL);

LONG Create(HKEY hKeyParent, LPCTSTR lpszKeyName, LPTSTR lpszClass = REG_NONE, DWORD dwOptions = REG_OPTION_NON_VOLATILE, REGSAM samDesired = KEY_ALL_ACCESS, LPSECURITY_ATTRIBUTES lpSecAttr = NULL, LPDWORD lpdwDisposition = NULL);
LONG Open(HKEY hKeyParent, LPCTSTR lpszKeyName, REGSAM samDesired = KEY_ALL_ACCESS);
LONG Close();
HKEY Detach();
void Attach(HKEY hKey);
LONG DeleteSubKey(LPCTSTR lpszSubKey);
LONG RecurseDeleteKey(LPCTSTR lpszKey);
LONG DeleteValue(LPCTSTR lpszValue);
};

and you can do this:

CRegKey reg;

reg.Open(HKEY_CURRENT_USER,"Software\Microsoft\Windows\CurrentVersion\Internet Settings");

and then

reg.QueryValue(...); //to read value
reg.SetValue(...) //to write value

Lucky the code machine30-May-02 2:15

30-May-02 2:15

I hope im not being a pain. I tryed this and it worked fine:

char* text;
//unsigned long* buffer;
DWORD* buffer;
unsigned long PerServer;
unsigned long Per1_0Server;
CRegKey reg;

reg.Open(HKEY_CURRENT_USER,"Software\\Microsoft\\Windows\\CurrentVersion\\Internet Settings");
reg.QueryValue(PerServer,"MaxConnectionsPerServer");

but when i try to read a string (the windows version name) with:

reg.Open(HKEY_LOCAL_MACHINE,"Software\\Microsoft\\Windows\\CurrentVersion");
reg.QueryValue(text,"ProductName",buffer);

i get an assertation error on the line "pdwCount!=null;" (in CRegKey) if i change buffer to anything using "buffer=(unsigned long*)999;" i dont get the error but i get no data.

Am i being stupid? I cant see where im going wrong.

An Expert is somone who has previously made ALL the Mistakes, I dream of this day. - Lucky

Martin Ziacek29-May-02 7:31

29-May-02 7:31

Lucky the code machine wrote:
Date:13:17 29 May '02

You had posted your answer to my message two minutes before I posted it. Confused | :confused:

Lucky the code machine29-May-02 7:29

Window Programming (Saving Results)

29-May-02 7:29

Nice! Im in England so i guess something to do with that? Confused | :confused:

Thanks a lot for that on registrys, i will try that. Looks good. Thanks

An Expert is somone who has previously made ALL the Mistakes, I dream of this day. - Lucky

29-May-02 7:01

I'm a fairly new Windows Programmer (C++). I was wondering if anyone had any good ideas on how saving of results work. For example, if I want to run a loop where a result is achieved every time, how could I save this data so that I could view and print all of the results together?

Trevor

Re: Window Programming (Saving Results)

Nish Nishant29-May-02 7:02

Nish Nishant

29-May-02 7:02

Anonymous wrote:
For example, if I want to run a loop where a result is achieved every time, how could I save this data so that I could view and print all of the results together?

You can use an array. If your data is complicated, you can have an array of structs.

Nish

Regards,
Nish
Native CPian.
Born and brought up on CP.
With the CP blood in him.

Count Number of Items in a struct

Anton A. Loukine29-May-02 6:36

Anton A. Loukine

29-May-02 6:36

What I am trying to do may be considered mental mastrubation, but here is the question:

can I programmatically:
- count the number of items in a structure;
- get access to any of the items by its index (but not by its name) while presersing the names of these items.

The following example should make it clear:

I have a struct:

struct BBG_SECURITIES {
long nRecords; // Number of Entries
CStringArray sName; // Security Name
CStringArray sTicker; // Security Ticker
CStringArray sMarket; // Security Market
CStringArray sIssuer; // Issuer
CStringArray sCoupon; // Coupon
CStringArray sFrequency; // Frequency
CStringArray sMaturity; // Maturity Date
CStringArray sCurrency; // Currency
CStringArray sCountry; // Country
CStringArray sDBRS; // DBRS Bond Rating
CStringArray sSP; // S&P Bond Rating
CStringArray sMoody; // Moody's Bond Rating
CStringArray sBloomberg; // Bloomberg Composite Bond Rating
};

And I am lazy to write all of that each time:

m_strCurrentUniverse
.nRecords = NULL
.sName.SetSize(0)
.sTicker.SetSize(0)
.sMarket.SetSize(0)
.sIssuer.SetSize(0)
.sCoupon.SetSize(0)
.sFrequency.SetSize(0)
.sMaturity.SetSize(0)
.sCurrency.SetSize(0)
.sCoutry.SetSize(0)
.sDBRS.SetSize(0)
.sSP.SetSize(0)
.sMoody.SetSize(0)
.sBloomberg.SetSize(0);

What I want to set up some kind of a loop:
int nItems = GET ITEM COUNT IN THE STRUCT
for (i = 0; i < nItems; i++) {
xxx = GET STRUCT ITEM
xxx.SetSize(0);
}

Any thoughts?

Thank you.

Rama Krishna Vavilala29-May-02 6:49

Rama Krishna Vavilala

29-May-02 6:49

Here are your options

1. Change to array

struct BBG_SECURITIES {
long nRecords; // Number of Entries
CStringArray* entries; // Security Name

BBG_SECURITIES()
{
entries = new CStringArray[13];
}
};

Looping then would be straight forward.

2. Unstructured and unsafe method

BBG_SECURITIES sec;

int nItems = (sizeof(BBG_SECURITIES) - sizeof(long))/sizeof(CStringArray);

CStringArray* pIter = (CStringArray*)&sec.sName;

for(int i = 0; i < nItems; i++)
{
pIter->SetSize(0);
pIter++;
}

Anton A. Loukine29-May-02 6:49

Anton A. Loukine

29-May-02 6:49

Thanks for your reply:

* Wouldn't this fail if the structure is NOT empty (e.g., I have 5 elements in each CStringArray):
int nItems = (sizeof(BBG_SECURITIES) - sizeof(long))/sizeof(CStringArray);

* I am not quite sure what you are doing here:
CStringArray* pIter = (char*)&sec.sName;

sName is supoposed to be unknown.

* Any other reasons for calling this an unsafe method?

Thanks

Rama Krishna Vavilala29-May-02 7:23

Rama Krishna Vavilala

29-May-02 7:23

Anton A. Loukine wrote:
CStringArray* pIter = (char*)&sec.sName;

Sorry a typo it should be,

CStringArray* pIter = &sec.sName;

Rama Krishna Vavilala29-May-02 6:55

Rama Krishna Vavilala

29-May-02 6:55

Actually best thing for you would be to write a devstudio macro.

Anton A. Loukine29-May-02 6:50

Anton A. Loukine

29-May-02 6:50

Can you elaborate on this a little bit. I am not familiar with macros and how they affect performance

Joaquín M López Muñoz29-May-02 8:47

Joaquín M López Muñoz

29-May-02 8:47

Although others have posted very smart ways to have the task you're asking for accomplisedh automatically, please let me warn you'd better stay away of nifty tricks and stick to the boring sequence of resettings. If you ever add another item to your struct, you'd probably have to remember all the places scattered in your code where you put that. Instead, add a method to your struct like this:

struct BBG_SECURITIES {
  ...
  void Reset()
  {
    nRecords = 0; // I guess you meant 0 instead of NULL
    sName.SetSize(0);
    ... //all of the others
  }
};

and use it accordingly. You can do it even better: as CStrings are constructed to the empty string by default, you can have it like:

struct BBG_SECURITIES {
  ...
  BBG_SECURITIES()
  {
    nRecords = 0; // all other member properly cted by default
  }  
  void Reset()
  {
    BBG_SECURITIES clean_struct; // have a fresh item
    (*this)=clean_struct; // and copy to the current object
  }
};

The ability to inspect the contents of a class (its members, methods, etc.) is called reflection and alas is lacking in C++ (altough Java and C# do have it and it's magical for some uses.)

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo