Re: about casting
Hello!
I still have a major problem and that is when I do
handle_ds->
in method initRules2 see below no method is listed from the intellisense.
The methods that is located in the coclass Handle_DS are also public at the
moment.
STDMETHODIMP CSyntaxObj::InitRules2(IHandle_DS* handle_ds, BSTR Provider,
BSTR DataSource, BSTR UserId, BSTR Password, BSTR ProductID, BSTR Revision,
BSTR ApplicationID, BSTR ApplicationRev, BSTR SubfileID, VARIANT_BOOL *bRes)
{
....
handle_ds->
....
}
One very strange thing is that I looked in the code to try to find if some
other interface class is sent into some
method in the COM and I found one with name AlterSyntax2. Here StrList is of
type IStringList2.
If I do StrList-> in AlterSyntax2 I get the same problem no method is listed
from the Intellisense.
I looked more into the code and found that in some places is IStringList
used as a parameter instead of IStringList2. So I just changed from
IStringList2 to IStringList in the idl file and h file and cpp file.
If I now do StrList-> in AlterSyntax2 several method is displayed by the
intellisense
I hope somebody can give me a solution to my problem.
STDMETHODIMP CSyntaxObj::AlterSyntax2(IStringList2* StrList, BSTR
ErrFilePath,VARIANT_BOOL *bNew,ISubfileLinesList **ppSubfileLines,
VARIANT_BOOL *bRes)
{
StrList->
}
Here I have listed the idl file containing the IStringList and IStringList2.
I have also listed the header file for StringList further below
import "oaidl.idl";
[
object,
uuid(3A25C87E-DA0D-4265-A70C-E6575406039E),
dual,
helpstring("ISyntaxItem Interface"),
pointer_default(unique)
]
interface ISyntaxItem : IDispatch
{
[propput, id(1), helpstring("property SyntaxError")] HRESULT
SyntaxError([in] BSTR newVal);
[propput, id(2), helpstring("property ErrorMessage")] HRESULT
ErrorMessage([in] BSTR newVal);
[propput, id(3), helpstring("property ErrorType")] HRESULT ErrorType([in]
BSTR newVal);
};
[
object,
uuid(0B8AF80B-B386-49ED-B1FD-FA31CEBB121E),
dual,
helpstring("IGeneralSyntax Interface"),
pointer_default(unique)
]
interface IGeneralSyntax : IDispatch
{
[id(1), helpstring("method CreateSyntaxObject")] HRESULT
CreateSyntaxObject([out, retval]ISyntaxItem **pVal);
[id(2), helpstring("method SyntaxCheckLine")] HRESULT
SyntaxCheckLine([in]BSTR strIn, [out, retval]VARIANT_BOOL *pbRetVal);
[propget, id(3), helpstring("property ErrorType")] HRESULT ErrorType([out,
retval] BSTR *pVal);
[propget, id(4), helpstring("property ErrorText")] HRESULT
ErrorMessage([out, retval] BSTR *pVal);
[propget, id(5), helpstring("property CommandString")] HRESULT
CommandString([out, retval] BSTR *pVal);
};
[
object,
uuid(C0E667AE-6FA0-4C51-9A23-8389F53949D1),
dual,
helpstring("IStringList Interface"),
pointer_default(unique)
]
interface IStringList : IDispatch
{
[id(1), helpstring("method Reset")] HRESULT Reset();
[id(2), helpstring("method MoveFirst")] HRESULT MoveFirst();
[id(3), helpstring("method GetNext")] HRESULT GetNext([out]BSTR* bsValue,
[out, retval]VARIANT_BOOL* bResult);
[id(4), helpstring("method AddString")] HRESULT AddString([in]BSTR
bsValue, [out, retval]VARIANT_BOOL* bResult);
[propget, id(5), helpstring("property Count")] HRESULT Count([out, retval]
long *pVal);
[id(6), helpstring("method LoadFromFile")] HRESULT LoadFromFile([in]BSTR
bsFile, [out, retval]VARIANT_BOOL* bResult);
[id(7), helpstring("method SaveToFile")] HRESULT SaveToFile([in]BSTR
bsFile, [out, retval]VARIANT_BOOL* bResult);
[id(8), helpstring("method GetAt")] HRESULT GetAt([in]long lIndex,
[out]BSTR* bsValue, [out, retval]VARIANT_BOOL* bResult);
[id(9), helpstring("method SetAt")] HRESULT SetAt([in]long lIndex,
[in]BSTR bsValue, [out, retval]VARIANT_BOOL* bResult);
[propget, id(10), helpstring("property ReadFileName")] HRESULT
ReadFileName([out, retval] BSTR *pVal);
[propget, id(11), helpstring("property SaveFileName")] HRESULT
SaveFileName([out, retval] BSTR *pVal);
};
[
object,
uuid(9F61E528-6B15-4f87-996A-7A11E4B692E9),
dual,
helpstring("IStringList2 Interface"),
pointer_default(unique)
]
interface IStringList2 : IStringList
{
[id(12), helpstring("method GetNextAsNumber")] HRESULT
GetNextAsNumber([out]LONG* lValue, [out, retval]VARIANT_BOOL* bResult);
[id(13), helpstring("method AddStringAsNumber")] HRESULT
AddStringAsNumber([in]LONG lValue, [out, retval]VARIANT_BOOL* bResult);
[id(14), helpstring("method GetAtAsNumber")] HRESULT
GetAtAsNumber([in]long lIndex, [out]LONG* lValue, [out, retval]VARIANT_BOOL*
bResult);
[id(15), helpstring("method SetAtAsNumber")] HRESULT
SetAtAsNumber([in]long lIndex, [in]LONG lValue, [out, retval]VARIANT_BOOL*
bResult);
[id(16), helpstring("method DeleteAt")] HRESULT DeleteAt([in] long lIndex,
[out, retval] VARIANT_BOOL* bResult);
[id(17), helpstring("method SaveToFileApp")] HRESULT SaveToFileApp([in]
BSTR bsFile, [in] VARIANT_BOOL bNew, [out, retval] VARIANT_BOOL* bResult);
};
[
object,
uuid(932E6679-DB0A-45AC-BFC5-17FC488DD205),
dual,
helpstring("IDTHTools Interface"),
pointer_default(unique)
]
interface IDTHTools : IDispatch
{
[id(1), helpstring("method InfoAboutPrintOutOnWeb")] HRESULT
InfoAboutPrintOutOnWeb([in]IStringList* pIStringList, [out, retval]
VARIANT_BOOL* bResult);
[id(2), helpstring("method SplitString")] HRESULT SplitString([in]BSTR
bsSearchString, [in] BSTR bsSeparator, [out, retval]IStringList**
pIStringList);
[id(3), helpstring("method GetAt")] HRESULT GetAt([in, out]BSTR*
bstrSource, long lPos,[out,retval] BSTR *bstrDestination);
};
[
uuid(E32C6CDD-7424-482C-BF8F-FAEF9B80E91C),
version(1.0),
helpstring("DTHToolsEx 1.0 Type Library")
]
library DTHTOOLSEXLib
{
importlib("stdole32.tlb");
importlib("stdole2.tlb");
[
uuid(A8B396CE-CE8F-419B-A458-E7F77A4E07A3),
helpstring("GeneralSyntax Class")
]
coclass GeneralSyntax
{
[default] interface IGeneralSyntax;
};
[
uuid(40B19535-CAE6-4F38-BFA4-1C964BACC3A6),
helpstring("SyntaxItem Class")
]
coclass SyntaxItem
{
[default] interface ISyntaxItem;
};
[
uuid(D4EB2809-0D58-4335-AB42-DBD53A02D6DF),
helpstring("StringList Class")
]
coclass StringList
{
//[default] interface IStringList;
[default] interface IStringList2;
};
[
uuid(1D252172-F15F-4CF1-9300-A355401FB67F),
helpstring("DTHTools Class"),
appobject
]
coclass DTHTools
{
[default] interface IDTHTools;
};
};
/****************************************/
/* StringList.h /*
/****************************************
// StringList.h : Declaration of the CStringList
#ifndef __STRINGLIST_H_
#define __STRINGLIST_H_
#include "resource.h" // main symbols
#include "StringLinkedList.h"
#define MAX_NUMBERLEN 64
/////////////////////////////////////////////////////////////////////////////
// CStringList
class ATL_NO_VTABLE CStringList :
public CComObjectRootEx<CComMultiThreadModel>,
public CComCoClass<CStringList, &CLSID_StringList>,
public IDispatchImpl<IStringList2, &IID_IStringList2,
&LIBID_DTHTOOLSEXLib>//,
//public IDispatchImpl<IStringList, &IID_IStringList, &LIBID_DTHTOOLSEXLib>
{
public:
CStringList();
HRESULT FinalConstruct();
HRESULT FinalRelease();
DECLARE_REGISTRY_RESOURCEID(IDR_STRINGLIST)
DECLARE_PROTECT_FINAL_CONSTRUCT()
BEGIN_COM_MAP(CStringList)
COM_INTERFACE_ENTRY(IDispatch)
COM_INTERFACE_ENTRY(IStringList)
COM_INTERFACE_ENTRY(IStringList2)
END_COM_MAP()
// IStringList2
public:
STDMETHOD(SetAtAsNumber)(/*[in]*/long lIndex, /*[in]*/LONG lValue, /*[out,
retval]*/VARIANT_BOOL* bResult);
STDMETHOD(GetAtAsNumber)(/*[in]*/long lIndex, /*[out]*/LONG* lValue,
/*[out, retval]*/VARIANT_BOOL* bResult);
STDMETHOD(AddStringAsNumber)(/*[in]*/LONG lValue, /*[out,
retval]*/VARIANT_BOOL* bResult);
STDMETHOD(GetNextAsNumber)(/*[out]*/LONG* lValue, /*[out,
retval]*/VARIANT_BOOL* bResult);
// IStringList
public:
STDMETHOD(SaveToFileApp)(/*[in]*/ BSTR bsFile, /*[in]*/ VARIANT_BOOL bNew,
/*[out, retval]*/ VARIANT_BOOL* bResult);
STDMETHOD(DeleteAt)(/*[in]*/ long lIndex, /*[out, retval]*/ VARIANT_BOOL*
bResult);
STDMETHOD(get_SaveFileName)(/*[out, retval]*/ BSTR *pVal);
STDMETHOD(get_ReadFileName)(/*[out, retval]*/ BSTR *pVal);
STDMETHOD(SetAt)(/*[in]*/long lIndex, /*[in]*/BSTR bsValue, /*[out,
retval]*/VARIANT_BOOL* bResult);
STDMETHOD(GetAt)(/*[in]*/long lIndex, /*[out]*/BSTR* bsValue, /*[out,
retval]*/VARIANT_BOOL* bResult);
BOOL AddString(LPSTR lpBuffer);
STDMETHOD(SaveToFile)(/*[in]*/BSTR bsFile, /*[out, retval]*/VARIANT_BOOL*
bResult);
STDMETHOD(LoadFromFile)(/*[in]*/BSTR bsFile, /*[out, retval]*/VARIANT_BOOL*
bResult);
STDMETHOD(get_Count)(/*[out, retval]*/ long *pVal);
STDMETHOD(AddString)(/*[in]*/BSTR bsValue, /*[out, retval]*/VARIANT_BOOL*
bResult);
STDMETHOD(GetNext)(/*[out]*/BSTR* bsValue, /*[out, retval]*/VARIANT_BOOL*
bResult);
STDMETHOD(MoveFirst)();
STDMETHOD(Reset)();
private:
BOOL SplitBuffer2Strings(LPSTR lpBuffer, DWORD dwSize);
CStringLinkedList m_StringList;
CString m_strReadFileName;
CString m_strSaveFileName;
};
#endif //__STRINGLIST_H_
//Tony
"Giovanni Dicanio" <giovanniDOTdicanio@REMOVEMEgmail.com> wrote in message
news:O2sCrAmVJHA.4376@TK2MSFTNGP04.phx.gbl...
"Tony Johansson" <johansson.andersson@telia.com> ha scritto nel messaggio
news:MrXZk.4591$U5.34211@newsb.telia.net...
Thanks a lot for you answer.
You have been of great help!
You are welcome.
class MyTest
{
...
IHandle_DS* m_handle_ds;
Question numer 1.
Can I for example assign the passed handle_ds pointer of type IHandle_DS
in class MyTest shown above like this
in InitRules2
MyTest* myTest = new MyTest();
myTest->m_handle_ds = handle_ds
You can do that, but it is important to respect the COM reference counting
rules to avoid resource/object leaks.
Every COM interface derives from IUnknown (so, also you IHandle_DS derives
from IUknown).
IUknown exposes three methods: AddRef(), Release(), and QueryInterface().
QueryInterface() is the equivalent of the C/C++ "cast" (or maybe better:
dynamic cast).
AddRef() and Release() have the purpose of managing reference counting of
COM interfaces.
In fact, in contrast to automatic garbage collection of C#, COM interfaces
are managed using explicit reference counting.
When you pass a COM interface to someone, you call AddRef() to increase
the reference counter (meaning: "I'm going to use this interface").
When you don't need the interface anymore, you call Release() to decrease
the ref counter (meaning: "Thank you, I have finished using it").
When the reference counter reaches 0, it means that the interface is no
required by anyone, so it is deleted (ATL implements the body of AddRef,
Release, and other boilerplate code for you).
So, you can store the COM interface pointer using a data member in another
C++ class, like you asked. But you should pay attention to call
m_handle_ds->Release() when you don't need that interface anymore. You
could do that e.g. in MyTest destructor. Proper thing to do is to also set
the pointer to NULL, to avoid dangling references, et.c.
// Safely release COM interface e.g. in MyTest destructor
if ( m_handle_ds != NULL )
{
m_handle_ds->Release();
m_handle_ds = NULL;
}
There are also smart pointer classes from ATL to automatically manage COM
reference counting, one of these is CComPtr:
http://msdn.microsoft.com/en-us/library/ezzw7k98(vs.80).aspx
So, you could use CComPtr< IHandle_DS > instead of raw pointer
IHandle_DS*.
When the CComPtr goes out of scope, Release() is automatically called,
etc.
Question numer 2.
In this class Handle_DS I have two object defined like this
CDataSource DS;
CSession Session;
Is it any restiction when I want to use these for example passing this
Session object into another method named foo
Could I for example do
foo(handle_ds->Session);
This is not clear to me.
Handle_DS is a C++ class; IHandle_DS is the COM interface. As previously
written, COM interfaces don't have "data members", they just expose pure
virtual methods via v-tables. If you mean the C++ Handle_DS class (without
the "I" prefix), being it a C++ class (and not a COM interface), you can
do everything inside there, as you do for normal C++ classes.
Giovanni