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And you can read from your CPropertiesData class in each of the OnSetActive method of the property pages and write it back out to the CPropertiesData class in the OnKillActive, in case a different property page has modified some of the data in between the visit to each page.
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Are there any good tutorials of a SDI GUI application, that explains what each line of code is doing? I know C++ but it is understanding the Windows GUI stuff where I need some help. How the framework is set up. How resources are loaded into a Window, etc.
Jerry
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jerry1211a wrote:
Are there any good tutorials of a SDI GUI application, that explains what each line of code is doing?
If you are using MFC, then you have access to the source. Beyond that, a romp through MSDN is in order.
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
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I was doing some MFC for some time and now i want to go in database programming; And i have some qusetions
1- people tell me to go to visual basic to do it easily i want to use vc
2- there are ADO,ODBC and stuff which one should i use ?
3- what online samples/tuts are good to get started with ?
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Leyusha wrote:
1- people tell me to go to visual basic to do it easily i want to use vc
Don't allow others to dictate what tool(s) you use. Each person uses a programming tool for their own reason(s) and those reason(s) are heavily biased. I much prefer to use VC++ over VB, but I'm also smart enough to know that any judgment I have against VB can likely be countered by any VB aficionado. Unless you happen to stumble upon a person that is an expert in both languages, a fair comparison is much like dust in the wind.
Leyusha wrote:
2- there are ADO,ODBC and stuff which one should i use ?
Each is a tool designed for a specific purpose. While they do overlap to a small degree, it all depends on the intended application as to which is better suited for the job. Often times more than one can be used with no noticeable differences. ODBC gives you access too hundreds of 16-bit ODBC data sources. ADO also gives you access too hundreds of ODBC data sources but using a 32-bit OLE DB interface instead. DAO has both 16 and 32-bit support and is native for Jet and ISAM databases.
Per MSDN:
ADO has one common yet extensible programming model for accessing data—thus eliminating the need to choose between DAO and RDO and all of the others. ADO is not a specific “implementation” of a data access interface like RDO or DAO but a programming model. It implements a common programming model against OLE DB.
DAO is an object interface that can be used to access ISAM (and ODBC) functionality using DAO/Jet or the remote RDO functionality using DAO/ODBCDirect. DAO is fairly easy to code and provides a rich set of cursors and cursor-less resultsets as well as DDL functionality.
ODBC is a recognized standard interface to a variety of relational data sources. It is fast and lightweight and provides a universal interface that is not optimized for any specific data source.
OLE DB is a low-level interface designed to be used by driver vendors that wish to expose a data source to ADO-aware applications or by C++ developers wishing to develop custom data components. OLE DB is not callable from Visual Basic as it is not COM automation-compatible.
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
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Or is it possible to reset clipping rectangle of the device context ?
I need to exclude some part of dc from drawing operations for a while and
then enable it again.
How to do this ?
Thank you !
rrrado
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OK I've found out that I can do what I need also by SaveDC and RestoreDC.
rrrado
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I have been asked to see if I can differentiate between when a system crashes and when it is inadvertently powered-off.
The reason for this is that I have a shell created which is used in place of the normal Windows Desktop. This shell application really acts as a locked down version, so as to only allow access to certain functionality. Whilst the Shell is running an audit log is kept of what the user is running. However during the running of the shell application the system may suddenly crash or get powered-off. So I would like to know if its possible when I go back into the system to check some attribute or value to determine if the system was powered off or it crashed.
If there is a way, is it easy or could it get complicated. The Shell is only a small application and I dont want to waste time on it if the returns are not going to be great. I presently write out to a temp file everytime the user goes into a specific application. The name of the file gets changed if the user comes out of the shell correctly. Then if the system crashes or gets powered off I just check for the temp file existing (meaning the shell did not close down properly). I then write something into the file stating that the data could be invalid. This obviously does not state if the reason was due to crash or loss of power.
Thanks,
Simes
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I think there is a windows message sent to all applications before power off/shutdown, but I don't remember which was it, try to search in windows messages.
rrrado
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WM_POWERBROADCAST
The WM_POWERBROADCAST message is broadcast to an application to notify it of power-management events. A window receives this message through its WindowProc function.
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Will the declaration __stdcall fun() will use pascal calling convention.
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Are you wanting to know about the __pascal or __stdcall calling convention? The former is no longer supported. Use of the WINAPI macro will resolve to the appropriate calling convention for the target.
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
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What I want is i would like my c++ fuction to use pascal calling convention? Will __stdcall helps me? Or first of all will it possible
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Anonymous wrote:
What I want is i would like my c++ fuction to use pascal calling convention? Will __stdcall helps me?
I doubt it, since they are nearly opposite of each other in regards to the stack. __stdcall pops arguments from the stack in right-to-left order while __pascal pops arguments from the stack in left-to-right order. See here for more.
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
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Don't you mean pushes arguments on the stack in the order you stated ? Also - I thought the two, _pascal and _stdcall are essentially the same except that _pascal is now obsolete - replaced by _stdcall.
The other difference is that _stdcall functions pop the stack prior to returning while the function caller restores the stack for _cdecl functions which provides support for functions taking variable numbers of arguments.
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Rick York wrote:
Don't you mean pushes arguments on the stack in the order you stated ?
Probably. What gets pushed must eventually get popped! At that level of detail, I'm not sure the OP cared.
With 16-bit code, differences between the two are important. With 32-bit code, __pascal is not used so it effectively resolves to nothing. That's why the WINAPI macro exists.
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
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Will it mean, __stdcall fun(int i, int j) will push i first then j and __cdecl fun(int i, int j) will push j first, then i. In both cases who pushes the parameters to the stack?
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Will it mean, __stdcall fun(int i, int j) will push i first then j and __cdecl fun(int i, int j) will push j first, then i. In both cases who pushes the parameters to the stack?
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I used some assembler files in my project .
But i get following error in my code .
Performing Custom Build Step on ..\Codecs1\Ce\Celpwin.asm
The system cannot find the path specified.
Error executing c:\winnt\system32\cmd.exe.
Please help me.
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Assembly code requires an assembler, which VC++ is not. You can, however, use embedded assembly code via the __asm keyword.
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
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Hi,
1. I have a function
fun(int &i, int&j){}
when i tried to call fun(++i, i++); it is showing the error " cannot convert parameter 2 from 'int' to 'int &'"
What is the reason
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I'm no C++ guru, but I think I remember reading something about the C++ standard that states if you update the value of a variable more than once in between sequence points, the behavior is undefined and the compiler may treat this case as it wishes.
My articles
www.stillwaterexpress.com
BlackDice
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Hi,
Can you please explain what is sequence point.
And one more thing if my function is fun(int&1, int&j, int &k) and if i try to call fun(++i, ++i, i++)
i will get error at 3rd parameter.
It is showing problem for i++ only, not for ++i.
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Anonymous wrote:
It is showing problem for i++ only, not for ++i.
It will show the problem for ++i as well. The reason it doesn't show the error is because the compiler is evaluating the argument right-to-left, and is stopping when it finds one in error - the 3rd one in this case.
Anonymous wrote:
Can you please explain what is sequence point.
A sequence point is a point in the code where all the side-effects up to this point have been evaluated. They occur at the end of a statement, at the comma operator, the && and || operators, and when a function is called after all the arguments have been evaluated. It is at these points that the effects of the ++ and -- operators occur. So in your case, you are modifying the value of i twice within a sequence point (the evalution of the function parameters).
Ryan "Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"
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Hi Ryan,
But each expression one after the other. So in C/C++
Fun(++i, i++) first i++ will be evaluated and then ++i is evaluated and after that only Fun will be called.
But my surprise is why
int i = 10;
printf("%d, %d, %d", ++i, i++, ++i); will print as 12, 11, 11.
But what I anm expecting is 13, 11, 11.
What is the reason?
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