Currently, I'm working on compiling old .cpp classes under C++ Builder XE. Apart from many troubles, there is one which I have completely no idea how to solve.
My code:
String txt = "<Not so long sql query>";
int licz = some_function(txt, dzeFDS); //1
//assigning licz to somewhere
txt = "<much longer query>";
licz = some_function(txt, budFDS); //2
Problem is that during second call of some_function program is stopped and i have this alert:
First chance exception at $75A1C42D. Exception class EDatabaseError with message 'budFDS: Type mismatch for field 'Function', expecting: String actual: WideString'. Process Call.exe (1896)
It's strange form be, bacause first call of some_function works fine, but this second one (with arguments with the same type) doesn't.
some_function code:
int __fastcall some_function(String txt, TIBDataSet *firDS)
{
firDS->Close();
firDS->SelectSQL->Text = txt;
firDS->Open(); //during debugging, exception occurs in this line
int count = 0;
while(!firDS->Eof)
{ count++;
firDS->Next();
}
return count;
}
Any ideas what why it happens?
Thanks in advance
There is much pain in your future.
Anyway, the problem you're having is with the database connection. There's a field in your database called "Function" that holds a string. This field came across as a String with the ancient database driver that this program originally used. Your shiny, new database driver is telling VCL to expect such things as Unicode, and VCL doesn't like to shove such things into plain Strings, so it expects you to have a WideString ready in which to shove it.
Fortunately, there are ways of beating VCL into submission. What you want to do, since you surely don't want to rewrite half the application by changing TIBDataSet, is to tell the connection not to bother with Unicode. In order to do this, you have to set up the TSQLConnection object with UseUnicode=false, which I hope (I have no way of testing VCL code anymore) should look something like this:
connection->Params->Add("UseUnicode=false");
Where connection is the TSQLConnection object. I think you have to do this before connecting to the database.
If that doesn't work, see if you can configure the database driver to not use Unicode.
Problem solved - this one field Function has other type in C++ Builder design view - it was TStringField, and rest fields has TIBStringField...
Related
First of all happy new year to everyone, hope you're doing well!
I'm working on a C++ project in which I need to call a C# DLL I created following the first answer of this post. Once I have the DLL, I need to call it from Qt, so by using dumpcpp and the .tlb file generated by regasm, I managed to get the .cpp and .h files to use my classes. Just as a reference, the namespace of the classes is Wrapper, and the main class is Device with guid {DD4A4896-C105-4C60-839B-B18C99C8FE15}.
Once I have the generated files to use the DLL, if I try to create a Wrapper:: Device instance on Qt, I get the following error:
QAxBase::setControl: requested control {dd4a4896-c105-4c60-839b-b18c99c8fe15} could not be instantiated
QAxBase::qt_metacall: Object is not initialized, or initialization failed
It doesn't give any more information, so I tried to check if the guid was stored on the system registry (I used the regasm command explained on the previously quoted post, and It said that it was successful, but you never know). Opening Registry editor and searching for the Guid revealed that it's present at: Computer\HKEY_CLASSES_ROOT\WOW6432Node\CLSID\{DD4A4896-C105-4C60-839B-B18C99C8FE15}, which, as far as I know, is the right route for these guids, and it points to the right DLL.
I though It may be due to some kind ActiveQt problem, and as the previously quoted post explained how to use that DLL from VS C++, I decided to give it a try, using this as an another reference. I've finished with this code, which is supposed to create an instance of my Device object
#include <iostream>
#include <atlstr.h>
#import "C:\Users\javie\Documents\Wrapper\Wrapper\bin\x86\Release\netstandard2.0\Wrapper.tlb" named_guids raw_interfaces_only
inline void TESTHR(HRESULT x) { if FAILED(x) _com_issue_error(x); };
int main()
{
try
{
TESTHR(CoInitialize(0));
Wrapper::IDevicePtr devPtr = nullptr;
TESTHR(devPtr.CreateInstance("{DD4A4896-C105-4c60-839B-B18C99C8FE15}"));
}
catch (const _com_error& e)
{
CStringW out;
out.Format(L"Exception occurred. HR = %lx, error = %s", e.Error(), e.ErrorMessage());
MessageBoxW(NULL, out, L"Error", MB_OK);
}
CoUninitialize();// Uninitialize COM
std::cout << "Hello World!\n";
}
However, this doesn't work either, the createInstance method throws an exception of Class not registered and HR=80040154. Again, according to Registry editor, the class is registered, so I don't understand the error. I've also tried with devPtr.CreateInstance("Wrapper.Device"), devPtr.CreateInstance("Wrapper::Device") or `devPtr.CreateInstance("Wrapper::CLSID_Device") as the links I posted suggest, but in those cases I get another exception with HR=800401f3 and message Invalid class string.
It doesn't matter whether VS or Qt Creator are opened as administrator or not, I get the exact same error.
I have run out of ideas, and I really need to be able to use that DLL from Qt using the files generated by dumpcpp.
Does any one know what could be happening? It feels quite strange to me.
If your C++ application is 64-bit, that's the answer right there, because your C# component is 32-bit (or MSIL but registered to the 32-bit hive). In situations like these, a simple test using VBScript is always useful.
Write a simple VB Script (test.vbs)
Dim obj
Set obj = CreateObject("Wrapper.Device") ' or whatever your ProgID is
MsgBox TypeName(obj)
Now, run this macro 2 ways: with 32-bit and 64-bit versions of VBScript:
32-bit > c:\windows\SysWow64\cscript.exe test.vbs
64-bit > c:\windows\system32\cscript.exe test.vbs
This is assuming your C# component is dispatch compatible. If it's not, then it will still give you differing results that you can use to debug.
Assuming automation/IDispatch compatible, one will work and one won't if you have registered your component correctly.
Have you registered correctly? When I use regasm, I always use the the switches /tlb /codebase when registering the C# component for COM.
Ok, in case someone find the same error, I'll explain the solution I found.
The problem was that in my case, the C# class I developed depended on another 32 bits dll which was not registered on my PC. Once I registered the other dll, everything worked fine.
I don't know why VS kept telling me that the class was not registered when my class itselft was registered, it was one of its dependencies that wasn't registered.
Anyway, I discovered this thanks to Joseph's comments, so thanks a lot for your help.
I implemented Aspose.Cells and Aspose.PDF into our companies existing application.
While I had some trouble with this (mostly caused by the fact that I tried to implement both APIs into the exat same file which was a bad idea)
I figured out how to make it work more or less.
My Problem now is while Aspose.Cells works perfectly fine and doesn't seem to have any unusual behavior Aspose.PDF already struggles with setting the license and even when I eventually got this to work I can't even initiate a Aspose::Pdf::Document.
So the first totally unusual thing is the way I had to set the License in the Example code given with the Aspose Package and in the official resources the license is set like this.
auto lic = System::MakeObject<Aspose::Pdf::License>();
lic->SetlLicense("c:\\Foo\fooproj\\Aspose.Total.C++.lic");
This code won't run on my machine and cause the error.
Rough Translation
food.exe triggered a breakpoint
Original
food.exe Hat einen Haltepunkt ausgelöst
The same happens when I initialise a System::String with a emtpy constructor like this.
auto lic = System::MakeObject<Aspose::Pdf::License>();
System::String str;
str.FromUtf8("C:\\foo\fooproj\\Aspose.Total.C++.lic");
lic->SetLicense(str);
BUT if I initialise the System::String with an empty String in the first place setting the license seems to work just fine so this works.
auto lic = System::MakeObject<Aspose::Pdf::License>();
System::String str(u"");
str.FromUtf8("C:\\Projekte\\Aspose\\Lizens\\Aspose.Total.C++.lic");
lic->SetLicense(str);
If this code above works and I try to make an object from Aspose::Pdf::Document this will crash.
void Aspose_pdf::helloWorld()
{
auto doc = System::MakeObject<Aspose::Pdf::Document>();
.....
.....
}
I actually have no idea what's going on. I am not using any using namespace commands at the moment.
Would be greate if someone had an idea how to fix this.
Edit:
The error occures exactly in smart_ptr.h in the following function.
typename std::enable_if<!IsSmartPtr<T>::value, SmartPtr<T> >::type MakeObject(Args&&... args)
{
System::Detail::OwnNextObject ownershipSentry;
T *const object = ::new T(std::forward<Args>(args)...);
ownershipSentry.CreatedSuccessfully(object);
return SmartPtr<T>(object);
}
in the second line so T *const object = ::new T(std::forward<Args>(args)...);
is "causing" the error or atleast here the error will ne triggered.
Edit2:
Here you will find a simple example of how my code looks in general.
I Started with implementing Aspose.Pdf into my Programm so I edited my
Additional Library directories,additional dependencies, additional include directories,preprozessor definitions and my stacksize to fit these settings given in the Aspose.Pdf examples.
After this I created my Aspose_Pdf class and tested it. worked perferctly so far.
After this I made the same edits to fit Aspose.Cells aswell. Also I created a class Aspose_Cells and tested it. While this worked now my Aspose_Pdf class stoped working. After a little time passed I managed to atleast get the License Activation for Aspose_Pdf to work from this point on I had the problems described above.
Additional Dependencies:
...
Aspose.PDF_vc141x64d.lib
aspose_cpp_vc141x64d.lib
Aspose.Cells.lib
Additional Librariedirectories:
...
..\Aspose\Aspose.PDF\lib\Debug
..\Aspose\Aspose.Cells\lib64
additional Includedirectories
...
..\Aspose\Aspose.PDF\lib\Debug
..\Aspose\Aspose.PDF\include\asposecpplib
..\Aspose\Aspose.PDF\include\Aspose.Pdf.Cpp
..\Aspose\Aspose.Cells\Include
..\Aspose\Aspose.Cells\Include\icu\include
..\Aspose\Aspose.Cells\Include\boost
I've never heard about Aspose.Pdf neither I know how does System::MakeObject< work. But for me it looks that all the code might be simplified to next:
Aspose::Pdf::License^ lic = gcnew Aspose::Pdf::License();
System::String^ str = "C:\\foo\\fooproj\\Aspose.Total.C++.lic";
lic->SetLicense(str);
When it comes to Pdf.Document the initialization might look like this:
Aspose::Pdf::Document^ doc = gcnew Aspose::Pdf::Document();
I am getting a storage fault when my code destructs a regex and I am mystified as to the reason. I suspect I am missing something stupid about regex.
A little background: I am a reasonably experienced C++ developer but this is my first adventure with the regex class. My environment is a little unusual: I edit and alpha test in MS Visual C++ and then take the code to another environment. The other environment is fully Posix-compliant and just happens to be an IBM mainframe. The code works fine on Windows but fails every time on the mainframe. The problem is not something fundamental to my mixed environment: I have been working in this pair of environments in this way for years with complete C++ success.
I define the regex in the class declaration:
#include <regex>
...
class FilterEvalEGNX : public FilterEval
{
...
std::tr1::basic_regex<char> regexObject;
// I also tried plain regex with no difference
Subsequently in the class implementation I assign a pattern to the regex. The code should be more complex than this but I simplified it down to assigning a static string to eliminate any possible side effects from the way the string would be handled in real life.
std::tr1::regex::flag_type flags = std::tr1::regex::extended;
// I have also tried ECMA and it made no difference
try
{
static const char pat[] = "(ISPPROF|SPFTEMP)";
regexObject.assign(pat, flags);
}
catch (std::tr1::regex_error &e)
{
// handle regex error
}
That works without error. Of course, there is subsequent pattern matching code but it is not part of the problem: if I destruct the class immediately after the above code I get the storage fault.
I don't do anything to the regex in my class destructor. The rest of the class has been working for years; I am adding the regex now. I think some "external" overlay of the regex is unlikely.
Here is the traceback of the calls leading up to the fault:
std::tr1::_EBCDIC::_Destroy(std::tr1::_EBCDIC::_Node_base*)
+00000066 40 CRTE128N Exception
std::tr1::_EBCDIC::basic_regex<char,std::tr1::_EBCDIC::regex
+000000C8 2022 FilterEvalEGNX.C Call
std::tr1::_EBCDIC::basic_regex<char,std::tr1::_EBCDIC::regex
+0000007C 1913 FilterEvalEGNX.C Call
FilterEvalEGNX::~FilterEvalEGNX()
The code in the vicinity of line 1913 of regex is
~basic_regex()
{ // destroy the object
_Tidy();
}
The code in the vicinity of line 2022 of regex is
void _Tidy()
{ // free all storage
if (_Rep && --_Rep->_Refs == 0)
_Destroy(_Rep);
_Rep = 0;
}
_Destroy() appears to be implemented in the run-time and I do not think I have the source.
Any ideas? Thanks,
Believe it or not, it appears to be a bug in the C++ runtime. I tweaked my simple example and now I can duplicate the problem in a 15-line main(). I am going to run this by some peers and then report it to IBM. They actually fix this stuff! They don't just respond with "yes, you have found an issue."
I am some ATL code that uses smart COM pointers to iterate through MS Outlook contacts, and on some PC's I am getting a COM error 0x80004003 ('Invalid Pointer') for each contact. The same code works fine on other PCs. The code looks like this:
_ApplicationPtr ptr;
ptr.CreateInstance(CLSID_Application);
_NameSpacePtr ns = ptr->GetNamespace(_T("MAPI"));
MAPIFolderPtr folder = ns->GetDefaultFolder(olFolderContacts);
_ItemsPtr items = folder->Items;
const long count = items->GetCount();
for (long i = 1; i <= count; i++)
{
try
{
_ContactItemPtr contactitem = items->Item(i);
// The following line throws a 0x80004003 exception on some machines
ATLTRACE(_T("\tContact name: %s\n"), static_cast<LPCTSTR>(contactitem->FullName));
}
catch (const _com_error& e)
{
ATLTRACE(_T("%s\n"), e.ErrorMessage());
}
}
I wonder if any other applications/add-ins could be causing this? Any help would be welcome.
FullName is a property and you do the GET operation (it's probably something like this in IDL: get_FullName([out,retval] BSTR *o_sResult)). Such operation works ok with null values.
My assumption is that contactItem smart pointer points to any valid COM object. In such case the formatting operation done by ATLTRACE can cause the problem. Internally it behaves probably like standard sprintf("",args...) function.
To avoid such problems just do something like below:
ATLTRACE(_T("\tContact name: %s\n"),
_bstr_t(contactitem->FullName)?static_cast<LPCTSTR>(contactitem->FullName):"(Empty)")
Just a guess:
Maybe the "FullName" field in the address book is empty and that's why the pointer is invalid?
hard to tell, because your code doesn't indicate which COM-interfaces you're using.
Does this make any difference?
ATLTRACE(_T("\tContact name: %s\n"), static_cast<LPCTSTR>(contactitem->GetFullName()));
In my example you format NULL value to a proper text value.
If the question is about the difference between FullName(as a property) and GetFullName() (as a method) then the answer is no. Property and method should give the same result. Sometimes property can be mapped to different methods then setXXX and getXXX. It can be achieved by using some specific syntax in IDL (and in reality in TLB after compilation of IDL to TLB). If property FullName is not mapped to method GetFullName then you will achieve different result.
So please examine file *.tlh after importing some type library to your project...
I am writing an background service application that has to automatically read data from Excel 2003 files. But no matter what I try, the method OlePropertyGet() always results in an EAccessViolation error while trying to read from address "00000800".
The error always occurs at the last line of this code snippet, and seems independent of what parameter the method receives:
Variant excel, workbooks;
try
{
excel = GetActiveOleObject("Excel.Application");
}
catch(...)
{
excel = CreateOleObject("Excel.Application");
}
workbooks = excel.OlePropertyGet("Workbooks");
I've done some extensive google search on this, but found nothing that's even remotely helpful, only this forum thread where someone has the same issue, but doesn't give any information about the cause or solution (it's somewhat funny that at one point the author mentions he knows the cause, but doesn't say what it is!).
I'm open to any ideas as to what is causing this and how to solve this problem, but also alternative approaches to Excel OLE automation.
My guess is its a null pointer issue..
It looks like neither GetActiveOleObject() nor CreateOleObject() worked.
Try checkign the validity of 'excel' before calling OlePropertyGet.
And I guess you should make sure you have Excel installed.
You can use Visual Studio Tools for Office (see http://msdn.microsoft.com/en-us/library/d2tx7z6d.aspx).
Or you can use ATL support to instantiate the object model provided by office.
Your code may not be able to resolve "Excel.Application" successfully, leading to a null pointer. It uses a registry lookup with that string to identify Excel. It sounds like you're missing that registry entry.
I use such code to determine validity of created objects(in C++ Builder):
Varaint excel = GetActiveOleObject("Excel.Application");
TAutoDriver<IDispatch> dispatcher;
dispatcher.Bind(excel, false);
if (dispatcher.IsBound())
{
Variant workbooks = excel.OlePropertyGet("Workbooks");
}