Re: Need help to return string value from COM

"Alexander Nickolov" <>
Mon, 19 Jun 2006 12:54:59 -0700
Wow, that much code when a simple API call would suffice...

STDMETHODIMP CMyObj::Echo(BSTR val, BSTR* ret) {
    *ret = SysAllocString(val);
    return (val == NULL) || (*ret != NULL) ? S_OK : E_OUTOFMEMORY;

Alexander Nickolov
Microsoft MVP [VC], MCSD

"Igor Tandetnik" <> wrote in message
news:%23hFfoy6kGHA.1260@TK2MSFTNGP05.phx.gbl... wrote:

I'm trying to create a .dll using ATL, which I want use in C#.

Can anybody please guide me to create a simple method / function which
takes string in input parameters and returns the same(string)..

// in IDL

HRESULT Echo([in] BSTR val, [out, retval] BSTR* ret);

// in C++

STDMETHODIMP CMyObj::Echo(BSTR val, BSTR* ret) {
   CComBSTR bstr;
   HRESULT hr = bstr.CopyTo(ret);
   return hr;

With best wishes,
   Igor Tandetnik

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