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I want to use std::stringstream to format data to a string like sprintf "%02d" as below:
char szWord[MAX_PATH];
int nValue=3;
sprintf(szWord,"%02d",nValue);
How do I do that by std::stringstream?
modified on Friday, April 9, 2010 5:17 AM
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stringstream does not print, but iostream does. Try the cout object as follows:
int x(3);
std::cout.setfill('0');
std::cout.setw(2);
std::cout << x << endl;
stringstream is used similarly, but as I said before it writes to memory, not the console.
Edit: did not pick up on the formating earlier.
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There is (I have been told) a way of using an entire dialog template as a resource in another dialog. This would be very usefull in organising things like a property sheet in one corner and something else in another place. Has anyone tried the mechanics of this?
Regards, 
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You don't use a dialog template as a resource in another dialog - to me this implies merging. I've never seen this done.
What is common is to:
- define the parent dialog template
- on the parent, define where a child dialog is to be placed by using a dummy control
- in the parent WM_INITDIALOG:
- call CreateDialog*() to create the child dialog from its template
- find the dummy control and it's extents
- delete the dummy and resize/position the child dialog to take its place
...cmk
The idea that I can be presented with a problem, set out to logically solve it with the tools at hand, and wind up with a program that could not be legally used because someone else followed the same logical steps some years ago and filed for a patent on it is horrifying.
- John Carmack
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LPWSTR S = L"Hello World!";
for (n = 12; n > 0; n--)
{
if (S[n] == 'W')
{
MessageBox (hwnd, L"Found W!", L"FilePosition", NULL);
}
}
error C2446: '==' : no conversion from 'int' to 'LPWSTR'
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'W' is supposed to be a wide character so use L'W'
You may be right
I may be crazy
-- Billy Joel --
Within you lies the power for good - Use it!
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As a side note, your loop limits are wrong, you should use
for (n=11; n>=0; n--)
or, better
for (n=wcslen(S)-1; n>=0; n--)
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
[My articles]
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If this is your actual code, you aren't getting that error. S[n] returns a wchar_t, not a LPWSTR. 'W' doesn't need to be L'W' since it will auto-promote to wchar_t.
(Plus, for(n should be for(int n.)
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Joe Woodbury wrote: 'W' doesn't need to be L'W' since it will auto-promote to wchar_t.
That should not be true.
It was true with old C++ version, where the wchar_t was not an independent type, and was just a typedef for "unsigned short", and "char" autopromote into "short" and become "unsigned".
In more modern versions, wchar_t can be set up as an independent type with a compiler switch and -now- it becomes a default by standard.
Autopromotion of char-s into wchar-t must not happen, since the "encoding scheme" used in strings may not fit: All negative chars (above 127) are not ASCII and hence may have different meaning if ANSI (depending on the codepage) or UTF (can be UTF-8).
That said, char to wchar_t is not a one-to-one arithmetic conversion. You may have four chars going into a single or a pair of wchar_t (think to UTF-8 to UTF-16 chinese).
2 bugs found.
> recompile ...
65534 bugs found.
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Good to know, but weird, in my opinion.
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
[My articles]
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That's was what i though when that differentiation was introduced.
But it saved me lot of time form char-type mismatching in strings!
The "werid" thing is that C++ is still taking the old C idea of "char are just numbers" and strings don't exist (there are character arrays and string manipulation functions).
Than wchar_t was introduced, and a type semantic was applied to it.
It would be more correct -nowadays- the case that even char should not have number semantic and a different type (may be byte and unsigned byte, or short short int) should be introduced to represent small integers)
I also wander why C and C++ standard are insisting with all those sort of short, long, long long, long long long, etc. instead of simply define integers as int_x where x is the number of bits (MS does it, but it's not "standard").
Then there might be char_x, incompatible with int_x unless of explicit conversions and functions.
2 bugs found.
> recompile ...
65534 bugs found.
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Well, after 'initial shock' I think you are actually right.
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
[My articles]
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This is more funny I don't know if it's related to the new standards or if not.
My program has a linked list data structure in C++.
So...
class Whatever
{
public:
LPWSTR *Info;
};
is my basic data structure.
I store info along the way from a ComboBox in a Whatever data structure.
Eventually I want to process several of Info and divide them in several Strings.
if (Test->Info[n] == L'/')
{
}
I end up getting these errors.
1>main.cpp(686): error C2446: '==' : no conversion from 'int' to 'LPWSTR'
1> Conversion from integral type to pointer type requires reinterpret_cast, C-style cast or function-style cast
1>main.cpp(686): error C2040: '==' : 'LPWSTR' differs in levels of indirection from 'int'
However if I address LPWSTR directly not through the C++ class data structure everything goes smooth as silk. 
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Try to change:
Fareed Rizkalla wrote: class Whatever
{
public:
LPWSTR *Info;
};
...to  :
class Whatever
{
public:
LPWSTR pInfo;
};
virtual void BeHappy() = 0;
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Like I said a ComboBox adds information into Info so their is buffering problem!
So Info size has to be pointer to be sized for the ComboBox text.
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LPWSTR* Info;
Info[n];
Info[n][m];
virtual void BeHappy() = 0;
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But it's not a 2 dimensional array.
int **cha;
cha = new int[10];
for (int r = 0; r < 10; r++)
{
cha[r] = new int[10];
}
So how do you target a character I have to pass 2 locations to Info.
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Yes, I was pointing out what was, not what should be and disagree with you anyway on that point.
char and wchar_t ultimately are just numbers and have no intrinsic meaning on their own--the compiler has no idea what encoding scheme you are using. Is it UTF-16BE, UTF-16LE? Even char doesn't imply what the code page is.
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I want to use multiThread to read and write database,but I do not how how to prevent the thread from reading db again and again,
for example, I want use Thread1 to read record 1 - 100,and use Thread2 to read record 101-200,but I don`t know how to control different threads to read different data?
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Thread synchronization is a big topic. Have a look at MSDN [^].
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
[My articles]
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caiguosen wrote: ...but I don`t know how to control different threads to read different data?
Is thread 2 not supposed to read until thread 1 finishes?
"One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"Man who follows car will be exhausted." - Confucius
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they can read together,but the content which thread one reads can not be read by thread2.
there will be many threads, just like client/server mode,
but how can i control these threads in order to let them read different data from the same database.
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I've never tried anything like this, but my first attempt would be to set some sort of filter (i.e., WHERE clause), like:
SELECT * FROM table WHERE 1 <= rownum AND rownum <= 100
SELECT * FROM table WHERE 101 <= rownum AND rownum <= 200
SELECT * FROM table WHERE 201 <= rownum AND rownum <= 300 Does that sound plausible?
"One man's wage rise is another man's price increase." - Harold Wilson
"Fireproof doesn't mean the fire will never come. It means when the fire comes that you will be able to withstand it." - Michael Simmons
"Man who follows car will be exhausted." - Confucius
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I have a CFormView where I want to display an image and show some buttons over the image. I get the device context for the view, create a compatible bitmap, use the LPPICTURE Render(*) function to display the image file into the DC, then use BitBlt(*) of CDC to display the image. The buttons are placed onto the form. This kind of works, although if I display another window over the form, or move the cursor into the title bar or the system status bar, all the buttons disappear. I would like to place the buttons dynamically, and tried to use SetWindowPos(*) for one of the buttons. But when I called SetWindowPos(*) for that button, everything (image and other buttons) disappeared. Is there a proper way to display buttons over an image so they don't disappear, and also to do so dynamically?
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