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Im using the following code n my program,
CString sAlrm = _T("");
sAlrm.Format("%-16s %-10s %-10s",pTagBase->GetTagName(),pTagBase->GetDescription(),pAlrmDisp->sStatus);
But it shows error as
error C2664: 'void ATL::CStringT<BaseType,StringTraits>::Format(const wchar_t *,...)' : cannot convert parameter 1 from 'const char [18]' to 'const wchar_t *'
with
[
BaseType=wchar_t,
StringTraits=StrTraitMFC_DLL<wchar_t>
]
Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast
The return value of GetTagName,GetDescription all are CString value.
What is the error?how can i avoid it.
Im using VS2008.
Anu
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It would appear that you're compiling with the Unicode character set selected. (Right click on the project in the Solution Explorer, select Properties; it's on the 'Configuration Properties/General' page.)
Your format string is being seen as a string of type char; to convert it to TCHAR's, which will automatically map to wchar_t's when Unicode is selected, use the '_T' macro, just as you did when you initialized the string -
CString sAlrm = _T("");
sAlrm.Format(_T("%-16s %-10s %-10s"),pTagBase->GetTagName(),pTagBase->GetDescription(),pAlrmDisp->sStatus);.
L u n a t i c F r i n g e
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Yes when i changed to UseMultiByte character set,i didnt get such kind of errors.
Thank you.
Anu
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Please mark his answer good by clicking "Good Answer" in his post.
“Follow your bliss.” – Joseph Campbell
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Before I get started, I would like to say that I know I am reinventing the wheel. That being said I would like to state that I am doing this as a new challenge in my programming.
I am wondering if anyone has any resources on developing A GUI toolkit; specifically in windows. My goal is to bypass the windows API entirely by using OpenGL to develop this toolkit, and then develop a small application using it.
I am a near fluent C++ programmer; I understand the STL, pointers, dynamic allocation, classes, OOP, ambiguity and polymorphism in code. I have little knowledge of the windows API, but I do have a working knowledge of OpenGL, using libraries such as Glut, gl, and glu.
I would like to stress that this is not something that has a deadline. It is not a project for a class or company. I am just a kid looking for a new challenge, in hopes to better prepare him self for his declared major in a year.
Regards,
Alex E.
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I found this open source GUI toolkit based on OpenGL - LibUFO[^]
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Thank you kindly. I hadn't thought of looking into open source toolkits and reverse engineering them. ^^;; I'll get right on that.
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I guess this would be your best bet, unless you can get hold of a book that is specific to GUI toolkits.
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Hi,
Is there a Windows Message being broadcast by the system when it enters/leaves Sleep/Hibernation Mode.
Thanks, 
Bram van Kampen
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Thanks,
Fits the bill like a glove.
![Rose | [Rose]](https://www.codeproject.com/script/Forums/Images/rose.gif)
Bram van Kampen
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If the previous answer helped you, please click on "Good Answer" and give it the deserved merit
Regards.
--------
M.D.V. 
If something has a solution... Why do we have to worry about?. If it has no solution... For what reason do we have to worry about?
Help me to understand what I'm saying, and I'll explain it better to you
Rating helpfull answers is nice, but saying thanks can be even nicer.
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Thanks,
You're right,
Just did so.
Bram van Kampen
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I want to run an application (see child) so that it can get the path of the current process (see parent). How?
Thank you masters!
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Your question is a little unclear. Why not simply pass the path to the process on the command line?
Steve
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Are you looking for GetModuleFileName Function?
You can get the path of the executable file of the current process using above function.
Sample code:
TCHAR szBuff[512];
GetModuleFileName(0, szBuff, 512);
--
"Programming is an art that fights back!"
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Well,
I would use GetModuleFileName() in the Parent process, and stuff it into the Environment of the Child Process:-
PARENTPROCESS=C:\Program Files\etc...
The Child Process can then queery the Environment, to get the Paren Process Name back.
Bram van Kampen
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Well you can use getcurrentdirectory to get the directory where the application was executed only if the parent process haven't changed that.
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raja jamwal wrote: Well you can use getcurrentdirectory to get the directory where the application was executed only if the parent process haven't changed that.
No, Not Realy. getcurrentdirectory does exactly what it says. That is not nescessarily the same dir as where the exe is located.
That's why I use GetModuleFileName();
Bram van Kampen
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yeah i know, the current directory variable attached with the module can be changed.
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Amen
Bram van Kampen
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EDIT:
The solution to my problem is to declare certain member variables as protected and use get and set functions to work with them. The reason I was reluctant to do this was because I thought it would be better to be able to read from protected variables directly but the speed difference compared to using a function to read a variable is no different, or so minute that it will never affect performance in any way. This is the standard for working with encapsulated variables so it's definately better than what I was doing before and allows for proper encapsulation.
I've decided to scrap the code below, what I thought was a good solution, because it's poor style and few people would understand exactly the point of it if they were to attempt to edit code that uses it :
#ifdef EDITINGCODE
#define PROTECTED protected
#else
#define PROTECTED public
#endif
class Class1
{
PROTECTED:
int var;
};
Quite often I only want to change member variables of classes using member functions and prevent these from being changed elsewhere in a program but still allow access to the variables data.
A common programming technique for this effect is to have a get function in a class that returns the value of a private / protected variable. But I figured that this technique could be inefficient when lots of accesses have to be made to those encapsulated variables because functions must be used to retrieve data.
So I've come up with a different solution that might be better. Hopefully i'm explaining ok what I want to achieve.
I want to know whether this technique is good or not ?
Basically, all I have to do is create a header file or a macro something like this :
#define FRIENDTOALL \
friend Class1; \
friend Class2; \
friend int function(); \
friend int main();
So it contains all the classes and functions in the program.
And then place the FRIENDTOALL macro in each class that contains encapsulated members.
That way it's possible to access private and protected variable members from anywhere in the program and still be able to see that they are not meant to be modified without using a class's functions.
Would it be wise to use this technique so I can see what variables are not to be modified without using member functions or are there any noticable draw backs to doing it this way ?
modified on Monday, December 28, 2009 9:46 AM
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I wouldn't really call this a good encapsulation technique, it's more like an anti-encapsulation technique. The whole point of making things protected and private is so that other classes can't access them directly, making every class a friend blows that idea out of the water. At that point why not just make everything public?
doug25 wrote: prevent these from being changed elsewhere in a program
Oh yeah, that's why we don't want to make everything public.
Especially with judicious use of inlining, the performance hit of using getters/setters is minimal in the grand scheme of things.
![Badger | [badger,badger,badger,badger...]](https://www.codeproject.com/script/Forums/Images/badger.gif)
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doug25 wrote: But I figured that this technique could be inefficient when lots of accesses have to be made to those encapsulated variables because functions must be used to retrieve data.
I think you're wrong here in the first place.
The latest compilers will definitely optimize the function calls with direct access.
You should turn on full optimization and check the assembly output that is generated.
I recommend you do not worry about optimization unless you're actually facing some sort of bottle neck.
'Cause you're simply ruining code encapsulation and more than that readability which will ultimately lead to a maintenance nightmare.
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Thanks for the comments,
EDIT:
with optimizations turned on, using value = var.var is 1.3 times faster than using a function like value = var.var(). But at millionth's of a second for getting a value 900 million times.
woops, I used an unsigned int for a very big loop, so the value wasn't actually retrieved 900 million times. I recalculated (incrimenting a double for loops) and found that one hundred million value = var.var is 1.0366 times faster than one hundred million value = var.var()
oh, unsigned ints have range 0 to 4,294,967,295
So I guess there isn't much difference in speed using a function to retrieve values.
nevertheless, that was really silly of me, I could easily achieve the same effect as what I originally intended by :
class Class1
{
protected:
int var;
}
and then uncomment public: when building a project.
The reason I would want to do this is because to me, protected values should be values that can be read from but not written to (outwidth the class), so when editing using intellisense it's useful for me to see what variables I intend to be protected in the "Let me know when it's ok and when it's not ok to change them" sense.
But I would probably only do this when i'm editing code, otherwise make variables always public if someone else is editing it. see what I mean.
but given that the speed difference of using a get function is so minute, I'll probably start using get functions. though for certain special cases I might want to treat a variable as "protected" but still be able to change it in different scopes so my technique might be useful there.
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