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Hi
I am using UnDecorateSymbolName() method get function name and argument data type. but i want actual argument variable name? i try this code like
void ExtractCppSymbol(char *szDecoratedName)
{
char szFunc[512];
if ( UnDecorateSymbolName(szDecoratedName, szFunc, 512, UNDNAME_COMPLETE > 0 ))
{
cout<
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Please do not post the same question in multiple forums. This has already been answered under C++.
Just say 'NO' to evaluated arguments for diadic functions! Ash
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Hi,
In my C++ app I'm recieving callbacks from managed code when some events are raised in a .NET control.
void CGraphControlView::ObjectDoubleClicked(System::Object^ sender, Northwoods::Go::GoObjectEventArgs^ e)
{
TRACE(_T(" Graph object double clicked\n"));
}
- How do I determine if the e->Object is of some class inherited from System::Object e.g. a GraphNode declared as:
public class GraphNode : GoBasicNode
?
/Juri
modified on Saturday, November 20, 2010 11:58 AM
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Call GetType and then check the IsClass property.
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Hi Nish,
I'm more or less a newbe in .NET and C#, could you show an example of how to do that.
Like
if (e->GetType() ..... then what ?
Regards
/Juri
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if(e->Object->GetType()->IsClass)
{
}
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Well if Object is declared as an object, e->Object will always inherit from an object (or be an object or a boxed object).
Do you have any sample of what you are trying to do?
Philippe Mori
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Hi,
i'm working with a itextsharp dll and trying to put a watermark ,but this error of compilation i don't how handled it .
Working in c# is fine but with vc++ 2003 show me Error C2691: 'int __gc[]'
line : iTextSharp::text::pdf::BaseFont *watermarkFont = NULL;
what i should do ?
any ideas please .
private: void WaterMark (String *newPdf,String *PdfIndex,String *TmpPath)
{
iTextSharp::text::pdf::BaseFont *watermarkFont = NULL;
Single watermarkFontSize = 14;
Single watermarkFontOpacity = 0.9;
Single watermarkRotation = 45.0;
String *watermarkText1=NULL;
iTextSharp::text::pdf::PdfReader *reader = NULL;
iTextSharp::text::pdf::PdfStamper *stamper = NULL;
iTextSharp::text::pdf::PdfContentByte *underContent = NULL;
iTextSharp::text::Rectangle *rect = NULL;
iTextSharp::text::pdf::PdfReader *pages = NULL;
try
{
iTextSharp::text::pdf::PdfReader *reader = new iTextSharp::text::pdf::PdfReader(PdfIndex);
int Pages = reader->NumberOfPages;
iTextSharp::text::pdf::PdfStamper *stamper = new iTextSharp::text::pdf::PdfStamper(reader, new System::IO::FileStream(String::Concat(TmpPath,newPdf),System::IO::FileMode::Create));
for (int j = 1; j <= Pages; j++)
{
watermarkText1 = j.ToString();
underContent = stamper->GetOverContent(j);
underContent->BeginText();
watermarkFont = iTextSharp::text::pdf::BaseFont::CreateFont(iTextSharp::text::pdf::BaseFont::HELVETICA, System::Text::Encoding::ASCII->EncodingName , false);
underContent->SetFontAndSize(watermarkFont,6);
underContent->SetColorFill(iTextSharp::text::BaseColor::BLACK);
underContent->ShowTextAligned(iTextSharp::text::pdf::PdfContentByte::ALIGN_CENTER, watermarkText1, 300, 700, 0);
underContent->EndText();
}
stamper->Close();
reader->Close();
}
catch (Exception *ex)
{
throw ex;
}
}
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I am using an old dll which is written in VC6 MFC( Builded with mfc42u.lib), I need to reuse the same in my C++/CLI application which is in VS2008( it use mf90u.lib)
while copying a string buufer to that old dll it cause an exception like "try to read/writing in protected meory"
String^ csMyString = gcnew String( "some value" );
MyClass* fromOldDll = new MyClass();
fromOldDll->m_csSomeString = static_cast<TCHAR*>(Marshal::StringToHGlobalUni(csMyString).ToPointer());
Is any other idea for implementing the same, it is not possible to modify the old dll
Thanks
Radhakrishnan G.
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Unfortunately, you cannot always mix DLLs like that. One solution would be to recompile the old DLL using VC 2008.
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hi all
in neural networks algo of face detection a term is used a lot " training neural network". what does it mean? and a file is used with extension of NNCP which is loaded first. as for as i know that file contains different patterns of faces. i wana implement the neural network algorithm but i don't understand how to train neural network and how to make this NNCp file which contains different face paterens.
any suggestions links will be appreciated.
thanks
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See reply to other reposts.
Just say 'NO' to evaluated arguments for diadic functions! Ash
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I have a function pointer with the following signature:
typedef bool (__stdcall *CB_CheckStatus)(unsigned);
When used as follows in a native app.
bool __stdcall UpdateStatus(unsigned pctCompl)
{
printf("\r%d%%...", pctCompl);
return false;
}
And as an parameter in a native function which uses it:
DLLAPI HRESULT __stdcall ReadFile(size_t Size, BYTE* Buff, CB_CheckStatus UpdateStatus)
Can I change the parameter as a void parameter? I want to map a delegate to this function pointer so I can utilize a BackgroundWorker for a mixed-mode wrapper
How would you do that?
Thanks
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I know that seemed like a bit vague, let me explain. I have in native code a callback that is used for passing to a function for means of acting as a percent complete mechanism in a native console app. The signature is as follows:
typedef bool (APIENTRY *CBUpdateValue)(unsigned PercentComplete);
That is passed as a parameter to a function that uses it for file reads and writes:
DLLAPI HRESULT APIENTRY GetFile(size_t FileSize, BYTE* Data, CBUpdateValue CompletStatus)
In the native code that uses the callback, an example of the use of the callback is
bool APIENTRY UpdateStatus(unsigned PercentComplete)
{
printf("\r%d%%...", PercentComplete);
return false;
}
The goal is to use this signature, but replace the printf call to send information to a BackgroundWorker object. It takes an unsigned and returns a bool. Because of this constraint, is it possible to use this for a BGW? I realize I have to map the function pointer to a delegate. Has anyone used something like this?
Thanks in advance
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Hi,
this article[^] of mine explains P/Invoke, including native code calling callbacks. While all examples use C# or VB.NET, similar things are possible using C++/CLI. Pay special attention to the STDCALL keyword.
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I should have mentioned that I am using IJW. The article provided no help but thanks anyway
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OK. Seems like IJW is a bit of a misnomer then? 
Anyway, managed methods are always called in STDCALL (there is no way to change that), your native code must adhere to that.
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Well perhaps, but compared to using a P/Invoke solution, it seems more natural to use C++/CLI especially when interoperation with native code is required.
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So what part are you stuck on? Converting between the function pointer/delegate? Or handling the background worker?
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Handling the Backgroundworker!
At the risk of being wordy, let me give a little more detail. It may help.
In native code, I have a callback used as a percent complete mechanism. Its signature is below:
typedef bool (APIENTRY *CB_UpdateStatus)(unsigned PercentComplete);
The function is below:
bool APIENTRY UpdateStatus(unsigned PercentComplete)
{
printf("\r%d%%...", PercentComplete);
return false;
}
Passed as an arg to a native function: HRESULT Result = NativeFileRead(Size, Data, UpdateStatus);
I need to wrap this function so it can be used as-is in native code but when wrapped will allow use in a graphical program by use of the background worker to get status back to a UI.
I modified the function pointer signature:
typedef bool (APIENTRY *CB_UpdateStatus)(unsigned PercentComplete, void* context);
and its use by the calling function:
bool APIENTRY UpdateStatus(unsigned PercentComplete, void* context)
{
printf("\r%d%%...", PercentComplete);
return false;
}
The native function that uses the callback now has an added parameter "void* context" - it's signature is below:
DLLAPI HRESULT APIENTRY NativeFileRead(size_t DataSize, BYTE* Data, CB_UpdateStatus UpdateStatus, void* context)
In native code I just pass a NULL so it causes no harm during debug and development. In managed code I need to wrap the function and use a BGW.
In my wrapper class I have this function signature:
Wrapper::FileRead(UInt32 DataSize, String^ managedFileHandle, BackgroundWorker^ worker)
My callback in the wrapper class now looks like:
bool __stdcall UpdateStatus(unsigned PercentComplete, void* context)
{
BackgroundWorker^ worker = static_cast<BackgroundWorker^>(&context);
worker->ReportProgress(PercentComplete);
return false;
}
I want to pass in the worker to the native function.
HRESULT Result = NativeFileRead(DataSize, Data, UpdateStatus, context);
The problem is now handling the BGW for a function that expects a void pointer.
Thanks Nish
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I don't understand why FileRead is passed a BackgroundWorker argument. Shouldn't FileRead be called from the worker thread's DoWork event?
And secondly, you cannot pass a managed reference through a void*. Instead create a delegate with managed arguments, and convert that to a function pointer before invoking the native FileRead method (so when the native FileRead invokes the native callback, what gets called eventually is your managed delegate handler). In the managed version, make the 2nd argument an Object^ (so that it can represent a BackgroundWorker). Hope that made sense.
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FileRead is called from the DoWork event in the C# app. Just left out. As to the second...
In the wrapper.h:
delegate bool UpdateProgressDelegate(unsigned int, Object^);
Wrapper::FileRead(....)
UpdateProgressDelegate^ upd = gcnew UpdateProgressDelegate(UpdateStatus);
GCHandle gch = GCHandle::Alloc(upd);
IntPtr ip = Marshal::GetFunctionPointerForDelegate(upd);
CB_UpdateStatus update = static_cast<HD_CB_UpdateStatus>(ip.ToPointer());
Then calling the native function:
Result = NativeFileRead(DataSize, Data, UpdateStatus &context);
Is that what you are suggesting? How does the native callback return percentcomplete through a BGW? I still need a native callback that takes the two args. Not real clear then
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alleyes wrote: Is that what you are suggesting? How does the native callback return percentcomplete through a BGW? I still need a native callback that takes the two args. Not real clear then
I quickly put together a small sample that should clarify what I am talking about. It's simplified code but you should get the gist:
typedef bool (*CB_UpdateStatus)(unsigned PercentComplete);
HRESULT NativeFileRead(size_t DataSize, BYTE* Data, CB_UpdateStatus UpdateStatus)
{
UpdateStatus(100);
return 0;
}
bool UpdateStatus(unsigned PercentComplete)
{
printf("From native code: %d\r\n", PercentComplete);
return false;
}
ref class Test
{
private:
BackgroundWorker^ worker;
public:
delegate bool ManagedUpdateStatus(unsigned int);
int FileRead(int dataSize, array<byte>^ data, ManagedUpdateStatus^ updateStatus, BackgroundWorker^ worker)
{
pin_ptr<ManagedUpdateStatus^> tmp = &updateStatus;
NativeFileRead(0, NULL, (CB_UpdateStatus)Marshal::GetFunctionPointerForDelegate(updateStatus).ToPointer());
return 0;
}
void Foo()
{
worker = gcnew BackgroundWorker();
worker->WorkerReportsProgress = true;
worker->DoWork += gcnew DoWorkEventHandler(this, &Test::Worker_DoWork);
worker->ProgressChanged += gcnew ProgressChangedEventHandler(this, &Test::Worker_ProgressChanged);
worker->RunWorkerAsync();
}
bool DoManagedUpdateStatus(unsigned int percentage)
{
worker->ReportProgress(percentage);
return false;
}
void Worker_DoWork(Object^ sender, DoWorkEventArgs^ e)
{
FileRead(0, nullptr, gcnew ManagedUpdateStatus(this, &Test::DoManagedUpdateStatus), (BackgroundWorker^)sender);
}
void Worker_ProgressChanged(Object^ sender, ProgressChangedEventArgs^ e)
{
Console::WriteLine("From the worker thread : {0}", e->ProgressPercentage);
}
};
int main(array<System::String ^> ^args)
{
NativeFileRead(0, NULL, UpdateStatus);
(gcnew Test())->Foo();
Console::ReadKey();
return 0;
}
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Thank you Nish, I get the gist.
The signature: typedef bool (*CB_UpdateStatus)(unsigned PercentComplete, void* context); is what I am pursuing although I appreciate the suggestion. Isn't it possible to box a managed object and get a pointer to it?
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