DSOFramer closing Excel doc in another window. If unsaved data in file, dsoframer fails to open with “Attempt to access invalid address”

Question

I'm using Microsoft's DSOFramer control to allow me to embed an Excel file in my dialog so the user can choose his sheet, then select his range of cells; it's used with an import button on my dialog.

The problem is that when I call the DSOFramer's OPEN function, if I have Excel open in another window, it closes the Excel document (but leaves Excel running). If the document it tries to close has unsaved data, I get a dialog boxclosing Excel doc in another window. If unsaved data in file, dsoframer fails to open with a messagebox: Attempt to access invalid address.

I built the source, and stepped through, and its making a call in its CDsoDocObject::CreateFromFile function, calling BindToObject on an object of class IMoniker. The HR is 0x8001010a The message filter indicated that the application is busy. On that failure, it tries to InstantiateDocObjectServer by classid of CLSID Microsoft Excel Worksheet... this fails with an HRESULT of 0x80040154 Class not registered. The InstantiateDocObjectServer just calls CoCreateInstance on the classid, first with CLSCTX_LOCAL_SERVER, then (if that fails) with CLSCTX_INPROC_SERVER.

I know DSOFramer is a popular sample project for embedding Office apps in various dialog and forms. I'm hoping someone else has had this problem and might have some insight on how I can solve this. I really don't want it to close any other open Excel documents, and I really don't want it to error-out if it can't close the document due to unsaved data.

Update 1: I've tried changing the classid that's passed in to Excel.Application (I know that class will resolve), but that didn't work. In CDsoDocObject, it tries to open key HKEY_CLASSES_ROOT\CLSID\{00024500-0000-0000-C000-000000000046}\DocObject, but fails. I've visually confirmed that the key is not present in my registry; The key is present for the guide, but there's no DocObject subkey. It then produces an error message box: The associated COM server does not support ActiveX document embedding. I get similar (different key, of course) results when I try to use the Excel.Workbook programid.

Update 2: I tried starting a 2nd instance of Excel, hoping that my automation would bind to it (being the most recently invoked) instead of the problem Excel instance, but it didn't seem to do that. Results were the same. My problem seems to have boiled down to this: I'm calling the BindToObject on an object of class IMoniker, and receiving 0x8001010A (RPC_E_SERVERCALL_RETRYLATER) The message filter indicated that the application is busy. I've tried playing with the flags passed to the BindToObject (via the SetBindOptions), but nothing seems to make any difference.

Update 3: It first tries to bind using an IMoniker class. If that fails, it calls CoCreateInstance for the clsid as a fallback method. This may work for other MS Office objects, but when it's Excel, the class is for the Worksheet. I modified the sample to CoCreateInstance _Application, then got the workbooks, then called the Workbooks::Open for the target file, which returns a Worksheet object. I then returned that pointer and merged back with the original sample code path. All working now.

Answer 1

@Jinjin

1. You can use the #import directive to import your Excel's OLB file. this should generate (and automatically include an Excel .tlh file which contains the structures for _Application (and the rest you need)). Ideally, you should find an OLB file that matches the earliest Excel version that you wish to support. The one on your local system is probably in c:\Program Files\Microsoft Office\Office12 (presuming you have Office 2007 installed). It may be named Excel.olb, or XL5EN32.OLB (different, obviously if you haven't installed the US English verion of Excel.
   So, copy the .olb file to your project source directory, then at the top of the source file, add a line for #import "XL5EN32.olb".

2. Yes, opens older versions. Best way to guarantee that this will be the case is to find an OLB file (mentioned in item 1 above) that is from an installation of Excel that is the earliest version you wish to support. I use an Excel9.olb from Office 2000. Works fine with my testing of Excel versions all the way to the latest from Office 2007.

3. Yes, you should use dsoframer normally after making these changes.

4. I'm afraid I probably can't do that due to restrictions of my employer. However, if you take the "stock" dsoframer project, make the changes described in part 1 of this post, and the changes I described in my earlier post, you have pretty much recreated exactly what I have.

Answer 2

@Jinjin: did you put the import statement (#import "XL5EN32.olb") in the cpp file where you are using the Excel::_Application? If not, do that... can't just add it to the project. If you have already done that, try also adding this statement to the cpp file where you are using those mappings #import "Debug\XL5EN32.tlh". The tlh file is a header that is generated by running the #import; you should find it in your Debug directory (presuming you're performing a Debug build).

Renaming _Application to Application (and the others) is not the right way to go. The _Application structure is the one that has the mappings. That is why you are not finding the app->get_Workbooks.

What file are you looking in that you are finding Application but not _Application?

Answer 3

Assuming you are using the DSOFRAMER project, you need to add this code to dsofdocobj.cpp in the CreateFromFile function, at around line 348:

CLSID clsidExcelWS;
hr = CLSIDFromProgID(OLESTR("Excel.Sheet"),clsidExcelWS);                   
if (FAILED(hr)) return hr;

if (clsid == clsidExcelWS)
{
    hr = InstantiateAndLoadExcel(pwszFile, &pole);
    if (FAILED(hr)) return hr;
}
else
{
    <the IMoniker::BindToObject call and it's failure handling from the "stock" sample goes here>
}

Then, define the following new member function in CDsoDocObject:

////////////////////////////////////////////////////////////////////////
// CDsoDocObject::InstantiateAndLoadExcel (protected)
//
//  Create an instance of Excel and load the target file into its worksheet
//
STDMETHODIMP CDsoDocObject::InstantiateAndLoadExcel(LPWSTR pwszFile, IOleObject **ppole)
{
    IUnknown *punkApp=NULL;
    Excel::_Application *app=NULL;
    Excel::Workbooks *wbList=NULL;
    Excel::_Workbook *wb;

    CLSID   clsidExcel;
    HRESULT hr = CLSIDFromProgID(OLESTR("Excel.Application"), &clsidExcel);
    if (FAILED(hr)) 
        return hr;

    hr = CoCreateInstance(clsidExcel, NULL, CLSCTX_LOCAL_SERVER,  IID_IUnknown, (void**)&punkApp);
    if (SUCCEEDED(hr)) 
    {
        hr = punkApp->QueryInterface(__uuidof(Excel::_Application),(LPVOID *)&app);
        if (SUCCEEDED(hr))
        {
            hr = app->get_Workbooks(&wbList);

            VARIANT vNoParam;
            VariantInit(&vNoParam);
            V_VT(&vNoParam) = VT_ERROR;
            V_ERROR(&vNoParam) = DISP_E_PARAMNOTFOUND;

            VARIANT vReadOnly;
            VariantInit(&vReadOnly);
            V_VT(&vReadOnly) = VT_BOOL;
            V_BOOL(&vReadOnly) = VARIANT_TRUE;

            BSTR bstrFilename = SysAllocString(pwszFile);

            hr = wbList->Open(bstrFilename, vNoParam,vNoParam,vNoParam,vNoParam,vReadOnly,vNoParam,vNoParam,vNoParam,vNoParam,vNoParam,vNoParam,vNoParam,0,&wb);
            if (SUCCEEDED(hr))
                hr = wb->QueryInterface(IID_IOleObject, (void**)ppole);

            VariantClear(&vReadOnly);
            VariantClear(&vNoParam);
            SysFreeString(bstrFilename);
        }
    }

    if (wb != NULL) wb->Release();
    if (wbList != NULL) wbList->Release();
    if (app != NULL) app->Release();
    if (punkApp != NULL) punkApp->Release();

    return hr;
}