Re: Anyone knows a tool to find C style casts ? - C / C++ / MFC Discussion Boards

_AnsHUMAN_ 24-Jul-07 1:25

24-Jul-07 1:25

void COnlyForU::OnKeyDown(UINT nChar, UINT nRepCnt, UINT nFlags)
{
if(nChar == 'a' || nChar == 'A')
     // Some code
else if(nChar =='b' || nChar == 'B')
     // We do something else
CDialog::OnKeyDown(nChar, nRepCnt, nFlags);
}

Somethings seem HARD to do, until we know how to do them.
Wink | ;-)

_AnShUmAn_

About Threading model

siddharthsan24-Jul-07 0:55

siddharthsan

24-Jul-07 0:55

Hi,

I am using Windows CE platform for my flashlite plugin application development.In the registry file(.rgs),threading model is set to Both to support both the STA and MTA.
Because of the threading model, I am getting fatal error as ,

"Single-threaded COM objects are not properly supported on Windows CE platform, such as the Windows Mobile platforms that do not include full DCOM support. Define _CE_ALLOW_SINGLE_THREADED_OBJECTS_IN_MTA to force ATL to support creating single-thread COM object's and allow use of it's single-threaded COM object implementations. The thr Cry | :((

eading model in your rgs file was set to 'Free' as that is the only threading model supported in non DCOM Windows CE platforms."

So, I changed the apartment type is changed to free,apartment etc.
like ThreadingModel = Both
ThreadingModel = Free
ThreadingModel = Apartment

But I am getting the same error.It is related to _WIN32_WCE macro?

Please help me to solve this error...

Siddharth

Re: About Threading model

DevMentor.org24-Jul-07 12:54

DevMentor.org

24-Jul-07 12:54

Are you sure you're not doing something wrong?

I am sure single-threaded COM is supported in WinCE as this is very easy to do. COM does this by using a hidden window and a message loop to serialize the calls aka com marshalling.

Do you have the source code for the COM object, can you build it for WinCE and then try to register the com object. Possibly the existing COM object was never built to run on WinCE as some one the APIs on WinCE are light-weight and don't transfer easily from Win32 platforms.. this is what I've read as I have never developed for a WinCE platform.

You can't simpley change a COM object that was STA to MTA free threading model because then your object is not thread safe and will have all kinds of data corruption bugs! You also need to build a thread safe COM object besides the registry setting.

Also STA and MTA support has nothing to do with DCOM!

Yours Truly, The One and Only!

Re: About Threading model

Matthew Faithfull25-Jul-07 1:09

Matthew Faithfull

25-Jul-07 1:09

Seems a bit odd. I use COM on CE all the time and have never seen this problem but I suppose that's because all our stuff is multithreaded. If you have control over your CE platform it's possibly worth experimenting with putting DCOM back in. Our CE 5.0 has it, Microsoft just took it out by default because some things don't work. We have plenty of components with ThreadingModel='Both'

I would suggest you develop an empty or dummy COM object specifically targetted at CE, using the EVC4 compiler (which is fussier than the regular VC compilers) to make sure you can get the infrastructure working. Once you've got a working shell you can port the useful code into it. You could always create a free threaded component and simply wrap every entry point with the same critical section so that old single threaded code can be used internally without breaking anything. It's not highly efficient but it should work.

Nothing is exactly what it seems but everything with seems can be unpicked.

Anyone knows a tool to find C style casts ?

sixio24-Jul-07 0:24

sixio

24-Jul-07 0:24

I'd like to have a reliable method to find C style casts in the source code. They can't be easily detected like 'static_cast' and the other C++ cast operators.
If there is a tool that can do the job, please point me to it.
Thanks in advance for your help.

Re: Anyone knows a tool to find C style casts ?

James R. Twine24-Jul-07 2:11

James R. Twine

24-Jul-07 2:11

A C-style cast is generally in the form of (type)ValueToCast. If you are looking for things like that for code-review purposes, also watch out for temporaries that are created using the following syntax: type(ValueToCast).

For example:

int iValueA = (int)dDoubleValue;
int iValueB = int( dDoubleValue );
 
FuncThatTakesACString( CString( "String Literal To Make A CString From" ) );

Things things should be rather easy to do a find-in-files search on, you can even automate VS using a macro to repeat the find using a list of types.

Peace!

-=- James
Please rate this message - let me know if I helped or not!<HR>If you think it costs a lot to do it right, just wait until you find out how much it costs to do it wrong!
Avoid driving a vehicle taller than you and remember that Professional Driver on Closed Course does not mean your Dumb Ass on a Public Road!
See DeleteFXPFiles

Re: Anyone knows a tool to find C style casts ?

DevMentor.org25-Jul-07 9:39

DevMentor.org

25-Jul-07 9:39

That fine for intrinsic C++ type which you know exist, but how about users defined types, which you are not aware of? I think our friend wants a tool that will catch all the type cast.

Yours Truly, The One and Only!

Re: Anyone knows a tool to find C style casts ?

James R. Twine25-Jul-07 11:08

James R. Twine

25-Jul-07 11:08

   Simple - you run something like Doxygen or some other documentation tool to get you all of the types that are being used by your application. You then feed that into my suggestion above.

   Brute force, yes, but it works; especially when you do not what to pay money for a good code review/analysis. Hell, lint with the right rules may do it for you.

   Peace!

Re: Anyone knows a tool to find C style casts ?

jhwurmbach24-Jul-07 2:20

jhwurmbach

24-Jul-07 2:20

sixio wrote:
I'd like to have a reliable method to find C style casts in the source code.

That is near to impossible.
Thats why I usually use the C++-style casts: The stick out.

Failure is not an option - it's built right in.

Re: Anyone knows a tool to find C style casts ?

DevMentor.org25-Jul-07 9:43

DevMentor.org

25-Jul-07 9:43

you don't need to worry about non-class types casting like int, long, wchar_t, etc ... leave them as-is!

what you want to do is a search as someone else said of the form
(class name)

get a list of all the class names in your project and then to a find in file of that c-style casting!

i.e class MyClass {...};

search for "(MyClass)" in the entire solution!

Yours Truly, The One and Only!

Problem with fopen

Maynka24-Jul-07 0:13

Maynka

24-Jul-07 0:13

Hi all,
I am facing problem in creating a file and writing to it.

The code looks like this:
TCHAR path[50];
fpLog = fopen((LPCSTR)path,"wt+");

When i am storing some predefined path in variable path.In this case the file is not created in the directory when fopen is executed but when i directly give path e.g D:\\file.txt the file is created and written also.
May be i am wrong in executing fopen.

Regards,

Re: Problem with fopen

codeII24-Jul-07 0:17

codeII

24-Jul-07 0:17

try _tfopen without casting a TCHAR to a char

Re: Problem with fopen

David Crow24-Jul-07 3:22

David Crow

24-Jul-07 3:22

Maynka wrote:
When i am storing some predefined path in variable path.In this case the file is not created in the directory when fopen is executed but when i directly give path e.g D:\\file.txt the file is created and written also.

Are you confusing an absolute path with a relative path?

"A good athlete is the result of a good and worthy opponent." - David Crow

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

Printing problem for GDI+ in HIMETRIC mode

Md. Ali Naser Khan24-Jul-07 0:03

Md. Ali Naser Khan

24-Jul-07 0:03

I've draw a spline in a view whose DC is in Himetric mode using GDI+.No problem is here. But when I print this same spline, it is not placed at proper location. I've observed that all points that are use for spline drawing, remain same and DC also is in HIMETRIC mode. What I have to do to solve the problem? Do I need to change the pointlist that construct the spline for printing? If so how can I do that?

Re: Printing problem for GDI+ in HIMETRIC mode

bob1697224-Jul-07 3:18

bob16972

24-Jul-07 3:18

Assuming you have the normal printing gotchas out of the way that are typical in GDI based applications, you need to ensure the GDI+ environment does not interfere with the GDI mapping routines if you are using those instead of the GDI+ transformations.

Jonathan de Halleux has some good tips about this general topic...
Tips on printing with GDI+[^]

Specifically, set

graphics.SetPageUnit(UnitPixel);

to prevent GDI+ interference in the mapping mode stuff.

Hope this helps

Re: Printing problem for GDI+ in HIMETRIC mode

Md. Ali Naser Khan27-Jul-07 1:02

Md. Ali Naser Khan

27-Jul-07 1:02

Thanks bob16972
for your help

connection problem

p_23-Jul-07 23:45

23-Jul-07 23:45

hi all
i have made an application in vc++ with mysql as database
i have face a problem that it gives a problem as unhandled exception access voilation
i use debugger but i cannot solve problem becoz debugger does not show error
it show LIBMYSQL! 10007764() and i could not understand this
please help me Rose | [Rose]

Re: connection problem

Rage24-Jul-07 1:41

Rage

24-Jul-07 1:41

paras_s12 wrote:
Wow. That has absolutely nothing related to your first post

Can you post the code that does not work ?

http://www.readytogiveup.com/[^] - Do something special today.
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Re: connection problem

p_24-Jul-07 1:55

24-Jul-07 1:55

if(!mysql_query(myDB,"SELECT passowrd from login WHERE user= \'" + user + "\'")
res=mysql_store_result(myDB);
if (!res)
{
MessageBox("Could not run query");
}
row = mysql_fetch_row(res);
{
i = (int) mysql_num_rows( res );
if (i != 1)
{
MessageBox("WRONG LOGIN PLEASE TRY AGAIN"," pop. ",MB_ICONASTERISK);
mysql_free_result( res ) ;

the problem is that data is not fetched
and i think exception is due to no value in res

Re: connection problem

David Crow24-Jul-07 3:24

David Crow

24-Jul-07 3:24

So why are you not stepping through this code to find the problem? The debugger is your friend. Learn to use it. Roll eyes | :rolleyes:

"A good athlete is the result of a good and worthy opponent." - David Crow

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

Diff. between DestroyWindow() and EndDialog()

Abhijeet Pathak23-Jul-07 23:13

Abhijeet Pathak

23-Jul-07 23:13

i want to execute some code when a dialog is destroyed, but the code in DeatroyWindow() function doesn't executes when i use EndDialog() but executes when i use DestroyWindow().

What is the diff. between these two and which should be best to use?

Re: Diff. between DestroyWindow() and EndDialog()

Rage23-Jul-07 23:26

Rage

23-Jul-07 23:26

I'd go for DestroyWindow(), or OnOK, OnCancel if you are using MFC. I've never done anything with EndDialog().

http://www.readytogiveup.com/[^] - Do something special today.
http://www.totalcoaching.ca/[^] - Give me some feedback about this site !

Re: Diff. between DestroyWindow() and EndDialog()

nitin323-Jul-07 23:52

nitin3

23-Jul-07 23:52

i use EndDialog()for modal dialog boxs and DestroyWindow() for modeless dialog boxes
Smile | :)

Re: Diff. between DestroyWindow() and EndDialog()

Rajkumar R23-Jul-07 23:56

Rajkumar R

23-Jul-07 23:56

Dialog Window Created by DialogBox, DialogBoxIndirect .. should be destroyed using EndDialog. OnOk, OnCancel internally uses EndDialog.

And surely OnDestroy() will get called when EndDialog is used.

Are u using MFC?

Re: Diff. between DestroyWindow() and EndDialog()

Mark Salsbery24-Jul-07 5:19

Mark Salsbery

24-Jul-07 5:19

DestroyWindow is something you call, not something that gets called. In MFC,
CWnd::DestroyWindow() is virtual. If you've overridden it, your override will get called at the
end of DoModal() but that doesn't make it a good place to do something when a dialog is destroyed.
That's a side effect of the way MFC does modal dialogs.

I think a better place is any time at or after you receive a WM_NCDESTROY message.

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

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