C / C++ / MFC

Casting of _bstr_t to CString

3-Jun-08 10:08

Member 1003415 wrote:
but still the same problem

Have you done a "rebuild all" since?

"Love people and use things, not love things and use people." - Unknown

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

Cancel Print Jobs

zoiomon3-Jun-08 8:32

zoiomon

3-Jun-08 8:32

Hi
I know I can use SNMP to get a lot of information from printers. But I'd like to know if I can stop users from printing if the total number of printed pages exceed some value, say 4000.

The printer in use is Xerox Phaser 4510, there are about 50 of them. I've already tried changing configurations by code, using SNMP++ but many printer attributes are read-only (including the one's to set the print host access list).

I'm open to alternatives!

Thanks, Icaro.

SimplySane3-Jun-08 5:01

SimplySane

3-Jun-08 5:01

How do I cast(not the C style cast plz) _bstr_t to CString?

toxcct3-Jun-08 5:11

toxcct

3-Jun-08 5:11

it's been asked so many times. check this[^] please.

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sudhir_Kumar3-Jun-08 5:17

sudhir_Kumar

3-Jun-08 5:17

Try this code:
_bstr_t bstr(_T("_bstr_t toCString test"));
CString str;
W2A(bstr, str.GetBuffer(256), 256);
strName.ReleaseBuffer();

Sudhir Kumar

toxcct3-Jun-08 5:29

toxcct

3-Jun-08 5:29

you code is not consistent. W2A() gets only one parameter, which is the string to cast.

also GetBuffer() is in its good use here (rarely goodly used, to it's important to notice it !) but it's not necessary. prefer using the CString::operator=() instead, and don't use W2A() but T2A() if the source is unicode independent (otherwise, it's your _b_str construction which shouldn't use _T())

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ThatsAlok4-Jun-08 1:02

ThatsAlok

4-Jun-08 1:02

Please refer this :-
http://www.codeproject.com/script/Forums/View.aspx?fid=1647&msg=2582403[^]

Anyways who voted you down, let me equal it!

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Never mind - my own stupidity is the source of every "problem" - Mixture

cheers,
Alok Gupta
VC Forum Q&A :- I/IV
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David Crow3-Jun-08 6:48

3-Jun-08 6:48

Have you even tried:

_bstr_t b("This is very hard.");
CString c1 = (LPCTSTR) b;
CString c2 = static_cast<LPCTSTR>(b);

"Love people and use things, not love things and use people." - Unknown

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

CPallini3-Jun-08 7:49

CPallini

3-Jun-08 7:49

Hey man, no C-style cast plz!
(coz 2 simple, plz plz urgent!)
Big Grin | :-D

If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.

This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke

Akt_4_U3-Jun-08 18:06

Akt_4_U

3-Jun-08 18:06

You can call copy() function of bstr to convert to CString.

eg:-
_bstr_t strTemp = "hi";
CString csTemp = strTemp.copy();

This will work fine.

akt

ThatsAlok4-Jun-08 1:06

ThatsAlok

4-Jun-08 1:06

Akt_4_U wrote:
_bstr_t strTemp = "hi";
CString csTemp = strTemp.copy();

hai, thats a nice bit of coding, but there is small performance issue, let me explain you, _bstr__t::copy will make a copy of underlining BSTR variable and pass it to csTemp, who again make copy of same and destroyed newly created BSTR variable. thought for small string the performance issue would be less, but for big string, this could present problem

cheers,
Alok Gupta
VC Forum Q&A :- I/IV
Support CRY- Child Relief and You/codeProject$$>

Mahesh Kulkarni3-Jun-08 20:57

Mahesh Kulkarni

3-Jun-08 20:57

_bstr_t bstrStart(bstr); <br />
<br />
CString s;<br />
<br />
s.Format(_T("%s"), (LPCTSTR)bstrStart);<br />
<br />
AfxMessageBox(s);

Try this. Hope this will work for u.

The secret of life is not enjoyment
but education through experience.
- Swami Vivekananda.

SimplySane4-Jun-08 17:19

SimplySane

4-Jun-08 17:19

Thanks.. I'm using this:

bstr_t bstrStart(bstr);

CString s;

s = static_cast<LPCTSTR>bstrStart;

EXECUTE code 1 after the other only

ThatsAlok4-Jun-08 1:01

ThatsAlok

4-Jun-08 1:01

SimplySane wrote:
How do I cast(not the C style cast plz) _bstr_t to CString?

_bstr_t have overloaded LPCTSTR parameter, you can directly cast your _bstr_t object to CString. without any problem.

cheers,
Alok Gupta
VC Forum Q&A :- I/IV
Support CRY- Child Relief and You/codeProject$$>

Trupti Mehta3-Jun-08 4:59

Trupti Mehta

3-Jun-08 4:59

Hello Friends,

I have the following lines of code. The CRHPostMessageToParent() calls parent to parent class methods.

AfxMessageBox(_T("Page2::Inside TellPArent"));

// Update deptStock obj with the parent
this->CRHPostMessageToParent(WM_CHANGED_DS, (int)&deptStock);
this->ShowWindow(SW_HIDE);
this->CRHPostMessageToParent(WM_SHOW_NEXT_VIEW, i);
AfxMessageBox(_T("Page2::Finished TellParent"));

These codes start running untill the previous line code is not completed. I want to ensure, that it should proceed to next line only when the first is completed. The CRHPostMessageToParent() calls PostMessage () to parent & returns void. The parent function OnChanged_DS() returns LRESULT.

In Java, this can be achived by assigning each task in thread and synchronizing it, which makes sure that the process is completed & then only the handle is released.

How do I achive the same in VC++6? I hope I have explained my situation to the best. If yet not, ask me.

Thanks

Terry

David Crow3-Jun-08 5:01

3-Jun-08 5:01

Trupti Mehta wrote:
How do I achive the same in VC++6?

You can also use synchronization.

"Love people and use things, not love things and use people." - Unknown

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

sudhir_Kumar3-Jun-08 5:19

sudhir_Kumar

3-Jun-08 5:19

You can use MFC sync classes like CMutex,CEvent and CSemaPhore.

Sudhir Kumar

JudyL_MD3-Jun-08 6:43

3-Jun-08 6:43

Does your CRHPostMessageToParent call PostMessage or SendMessage? Using SendMessage means that control does not return until the message has been processed which sounds like what you want.

Judy

David Crow3-Jun-08 6:49

3-Jun-08 6:49

JudyL_FL wrote:
Does your CRHPostMessageToParent call PostMessage or SendMessage?

Did you miss:

The CRHPostMessageToParent() calls PostMessage ()...

"Love people and use things, not love things and use people." - Unknown

"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne

JudyL_MD3-Jun-08 6:53

3-Jun-08 6:53

DavidCrow wrote:
Did you miss

Yes and no Smile | :)

. Yes, in that I didn't see the exact API function name and read the function description as "post a message." No, in that the function name implies Post instead of Send. More important was to make sure the OP was aware of the difference between PostMessage and SendMessage - unclear from the original post.

Judy

Trupti Mehta3-Jun-08 21:18

Trupti Mehta

3-Jun-08 21:18

It calls the PostMessage(message, WPARAM, LPARAM)

How do I achieve the goal? Can you give some guidance/example to work with CEvent etc classes as mentioned in ealier post.

Thanks

Terry

JudyL_MD4-Jun-08 3:00

4-Jun-08 3:00

I'm not the one who mentioned using CEvent. My suggestion was to call SendMessage instead of PostMessage to make the caller wait until the message was processed.

Judy

Trupti Mehta4-Jun-08 4:14

Trupti Mehta

4-Jun-08 4:14

Oh sorry Judy. must have read in some website for solution of the problem.

Anyways, I changed from PostMessage to SendMessage. Was just wondering will it make any differnece in using any of those. I mean, i changed from post to send will that make any other impact on the application other than not returning till the message is posted. Am just curious about it.

Thanks Judy.

Thanks

Terry

JudyL_MD4-Jun-08 4:34