Javascript problem with calling get_External method - COM Discussion Boards

Hi All,

When I try instantiating a component from within a queued component (c# .net BTW), the component won't instantiate and the message moves to the dead queue.

If I remove the code and just print a message box it works,
If I add the code to another non COM+ project it works fine,

I reckon it's a security thing, I'm getting an unspecified error!!!

Any help would be appreciated.

Thanks,

Cian

Hi,

I am trying to do drag and drop to explorer with my own IDataObject implementation.
I tried the MFC class COleDataSource at first. It was quite convenient yet not good enough because it does not support IAsyncOperation. That made the main thread freeze during the D&D operation. So I tended to implement IDataObject by myself.
However, none of the samples I found did delayed rendering with IDataObject, neither is there any documentation over that topic. I post the question on MS groups but got no response.
A google search only hit 14 pages. Only 1 out of that 14 pages helped a little
http://www.parsian.ath.cx/books/0-7897-0844-2/ch14.htm
Seems like OLE is using a hidden window to handle the render request. But how do I do the same thing by myself?

Can anybody throw me some light?

Thanks a lot

;PDear all,

I am developing an application for Windows NT/2000/XP in which I want to create a folder whose size should not exceed 5MB. And should promt for error if data exceeds 5MB
Is there any way to fix size of folder ?
( I know that there is ICopyHook for this but i donot know much about ATL COM)

Please comment!

Ideally, you would implement ICopyHook in an ATL/COM object and use the callback in conjunction with shell folder notifications. this should work for your application. Smile | :)

Can you send some sample code for this ??

I've been getting this error from time to time:
ASP 0177 The component is configured to use synchronization and a thread has timed out waiting to enter the context.

Is anybody familiar with this error message?
Would appreciate any help

Thanx!

;PDear all,

I am developing an application for Windows NT/2000/XP in which I want to create a folder whose size should not exceed 5MB. And should promt for error if data exceeds 5MB
Is there any way to fix size of folder ?
( I know that there is ICopyHook for this but i donot know much about ATL COM)

Please comment!

I am new to COM. I have been trying to incorporate the WebBrowser control into an MFC program. I have been using as an example and article from MSDN -http://www.microsoft.com/mind/0798/webbrowser.asp.
In this example VBScript is used. I have been trying to use JavaScript instead. I am unable to change a value with a COM method when I pass a value from Javascript;

IN VBSCRIPT:
sub get_property_value_onclick()
i=window.external.get_propert(property_name.value, value)
if i<>0 then
property_value.value=value
MsgBox property_name.value & " = " & value, 0, "Successfully retrieved property"
else
MsgBox "Cound not find value for property '" & property_name.value & "'", 0 , ""
end if
end sub

In Javascript:
function get_property_value_onclick(namevalue,value)
{
var value = "test";
var i = window.external.get_property(property_name.value,value)
if (i != 0)
{
property_value.value=value;
var strMsg;
strMsg = "Successfully retrieved property:" + property_name.value + " = " + value ;
alert( strMsg);
}
else
{
var strMsg;
strMsg = "Could not retrieve" + property_name.value + " = " + value ;
alert( strMsg);
}

}

The COM Method:
HRESULT my_application::get_property(LCID lcid,
WORD wFlags,
DISPPARAMS* pdispparams,
VARIANT* pvarResult,
EXCEPINFO* pexcepinfo,
UINT* puArgErr)
{
if (wFlags & DISPATCH_METHOD)
{
if (pdispparams->cArgs!=2)
{
return DISP_E_BADPARAMCOUNT;
}

// force to string
VARIANT arg1;
VariantInit(&arg1);
HRESULT hr=VariantChangeType(&arg1,
&pdispparams->rgvarg[1],
0,
VT_BSTR);
if (FAILED(hr))
{
*puArgErr=1;
return hr;
}

string str;
com_util::bstr2string(arg1.bstrVal,str);

// try to find element
string2variant_map::iterator it=propertymap.find(str);
if (it==propertymap.end())
{
if (pvarResult)
{
V_VT(pvarResult) =VT_BOOL;
V_BOOL(pvarResult)=FALSE;
return S_OK;
}

if (!pexcepinfo)
{
return E_INVALIDARG;
}

// raise exception
memset(pexcepinfo,0,sizeof(EXCEPINFO));
pexcepinfo->wCode =1001;
pexcepinfo->bstrSource =SysAllocString(L"WebBrowser Demo");
pexcepinfo->bstrDescription =SysAllocString(L"No entry for the key");

return DISP_E_EXCEPTION;
}

hr = VariantCopy(pdispparams->rgvarg[0].pvarVal,&(*it).second);

if (pvarResult)
{
V_VT(pvarResult) =VT_BOOL;
V_BOOL(pvarResult)=TRUE;
}

return S_OK;
}

return DISP_E_MEMBERNOTFOUND;
}

The function VariantCopy(pdispparams->rgvarg[0].pvarVal,&(*it).second);
returns a bad varibale HRESULT. Bu tit works OK in VBSCRIPT. Any idea on how to solve this?

thanks,
RAM_MR

I have an MFC application with an atl object. Now I want to know if a user started the application or if the application was started by the scum, so I can (amongst others) deside whether to show or hide the windows of the application. Anyone knows how to do this ?

Never mind, I already found what I was looking for: AfxOleGetUserCtrl().

Hi, I need to create a new Activex control by sub classing another Activex control. This will retain all the old functionality plus some other functions can also be added, i have tried doing it through the MFC ATL wizard, but that only create a wrapper araound it. Also MFC's ActiveX control wizard does seem to support sub classing of some MS standard controls only.
if you have a way to acheive this then please do help.

Mayank Goyal

Hi, I have an MFC application on which I want to put a COM interface so other applications can interface with my application. I succeeded in doing this, but now I have several object that can be created from outside my application. What I want is to provide a single object that creates the other objects. Can (and if so, how?) I shield these objects so they can not be created from outside my own application ?

One solution is containment. Another solution is aggregation, but only allow access to certain interfaces.

Kuphryn

Kuphryn, thanx for your answer, but could you elaborate your answer? How does containment work? Can you show me an example or article?

Concept of containment is as C++'s "has a" inheritance relationship. In other words, the outside COM object containers interfaces that will then utilize the inner object. The outsider exposes whatever functions it wants.

Kuphryn

Your non-creatable object should not have the class-factory. However I don't know how to make it possible in MFC.

With best wishes,
Vita

I found what I was looking for. I just have to remove the coclasses from the idl file, so the classes are not registered. This way external applications can only access the main (co-)class. Now the 'non-coclasses' cannot be created with CoCreateInstance anymore, instead they have to be created by calling their own static CreateInstance method.

I want to export data from a MFC program to EXCEL 97.
The function prototypes are in excel8.h
This is all part of excel8.olb. The only documentation I can find is for VB (vbaxl8.hlp on the MS Office distribution CD)
WHERE CAN I FIND THE DOCUMENTATION FOR THE FUNCTIONS OF excel8.h (for C/C++ not VB)

Anybody who knows COM, and OLE Automation should know...
I am just a rookie when it comes to this part of programming

Ethernal gratitude is guaranteed...

Daniela

I have to reply to my own post...
There is NO documentation for EXCEL Automation for C++.
It is extremely difficult using the VB documentation to get the C++ code right.
For example

range.PasteSpecial(Paste, Operation, SkipBlanks, Transpose)

In VB, all 4 parameters are VARIANTS
in the C prototype file excel8.h, the first two parameters
are of type long.
The "#define" for parameter Paste can nowhere be found

I found a pathetic way to work around my problems.
Just record a bunch of macros in EXCEL and call them from the C program

myapp.Run( COleVariant("MyMacro"),...)

//there are 30!!! optional parameters instead of the periods

Daniela

I am having the same problem. Augh.

If you find any good documentation please let me know.

Mardigin

hi there..

i am enabling mfc in an activex control and what happens is that when i debug it ..it throws an access violation in OLE32.lib..
dont know why..ne ideas? Smile | :)

regards
safee

thanks amigo..
it got resolved..
i logged on today ... sorry for keeping u waiting..

regards
safee

I [users] get this error when the service has run for a long time...
Any idea about this?
the event log shows..
----------------------------------------------------------------------
The COM+ Services DLL (comsvcs.dll) was unable to load because allocation of thread local storage failed.

Process Name: MyExe.exe
Error Code = 0x80070008 : Not enough storage is available to process this command.
COM+ Services Internals Information:
File: .\comsvcs.cpp, Line: 289

----------------------------------------------------------------------

After seraching in the net, I realized that I am not the only one to get this problem... There are many executables which get this error. Apparently we are all doing the same kind of process.. [like calling CoInit many times (with proper un-inits)..etc]

But, nowhere a solution is discussed... any luck here??

Thanks for your time!
Rose | [Rose]

I have done a GIS implementation in VC++ with Ms-access as back end iwant to convert this into Activex control & place it on the web .Can Anybody helpme out? Confused | :confused:

A.Satish Kumar

Hi,

I've created a DCOM Server through the ATL COM Appwizard, I've added a custom (IUnknown) interface and added some methods as below;

[helpstring("method GetComputerName")] HRESULT GetComputerName([out] BSTR *pName);
[helpstring("method GetComputerTime")] HRESULT GetComputerTime([out] long *lTime);

I was able to compile and call these methods thru the client and successfully get the values even from a remote machine.

Now I added a CLIENTINFO Structure in a header file and included the file in the idl using the #import directive,

#import "ClientInfo.h"

I added another method with a pointer to the ClientInfo structure as the parameter as follows

[helpstring("method GetComputerName")] HRESULT GetComputerName([out] LPCLIENTINFO pClInfo);

I was able to compile the code, but when i call this function from the client code, i get an exception and it crashes.

I want to know if we can pass User-Defined Data structures as parameters in a DCOM server? Why is this giving a problem even though i have derived the interface thru IUnknown? Shud we use VARIANTs here, but why shud we since i havent specified an IDispatct \ Automation interface?

The same thing works fine if i create an IN_PROC DLL.

Please tell me how we can achieve this in DCOM, also pls direct me to any examples or tutorials or articles on this.

Thanks,
Anand