How do I pass a C# interface to an external COM object for its use?

Question

UPDATE:

I found that the IID for ITfDocumentMgr was in the registry, but the IID for ITextStoreACP was not. When I removed the [Guid("28888....")] from my ITextStoreACP interface definition, the Push() method did not crash, I suspect because my class was not reporting it had that interface. I then placed it back and made the assembly, class, and interface NOT COM visible. Again, my AdviseSink method is not called.

Any thoughts on this would be appreciated.

---

NEAR ORIGINAL POST:

I am trying to integrate Text Services Framework into my C# application, with my C# application as the TSF client (as opposed to a TSF service). I can get the TSF COM interfaces to create a document manager okay. I have created a text store that implements the ITextStoreACP.

[ComVisible(true)]
public class TextStore : ITextStoreACP
{
    public uint AdviseSink(
        [MarshalAs(UnmanagedType.Struct)] ref IID Iid,
        [MarshalAs(UnmanagedType.IUnknown)]  Object pUnknown,
        uint Mask
        )
    {
        ITextStoreAcpSink Sink = pUnknown as ITextStoreAcpSink;
        return 0;
    }
....
}

After I create a context that uses my ITextStoreACP, I then use DocumentMgr.Push() to use the context that references my text store. In turn, the TSF framework should then call my ITextStoreACP.AdviseSink() method with its sink interface so that I can notify the framework when changes occur to the text store contents.

public partial class Form1 : Form
{
    static ITextStoreACP pStore = new TextStore();
    static Object pIunknown;

    static ITfContext Context;
    static ITfDocumentMgr DocMgr;
    static IThreadMgr ThreadMgr;


    protected override void  OnLoad(EventArgs e)        
    {
        base.OnLoad(e);

        TfClientId Tid = new TfClientId();
        TfEditCookie Cookie = new TfEditCookie();
        uint hr;


        // Get a new thread manager...
        ThreadMgr = TsfInterfaces.CreateManager();
        // Activate the thread manager and get our cookie back...
        hr = ThreadMgr.Activate(out Tid);
        // Create a document manager for our use...
        hr = ThreadMgr.CreateDocumentMgr(out DocMgr);

        // Get the IUnknown interface to pass to CreateContext()...
        pIunknown = pStore as Object;

        // Create a context to work in, designating our text store for our use...
        hr = DocMgr.CreateContext(Tid, 0, pIunknown, out Context, out Cookie);

        try
        {
            // Select our context to work in now. With a text store as part of
            // the context, the Text services framework should call into our
            // text store object with its sink interface. 
            //
            //     But it crashes instead.
            //
            hr = DocMgr.Push(Context);
        }
        catch
        {
        }

    }

}

I am using the ITfDocumentMgr interface definition here:

    [Guid("aa80e7f4-2021-11d2-93e0-0060b067b86e")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public interface ITfDocumentMgr 
{
    uint CreateContext(
        TfClientId Tid, 
        uint Flags,
        [MarshalAs(UnmanagedType.IUnknown)] Object pUnkUnique,
        [MarshalAs(UnmanagedType.Interface)] out ITfContext pContext,
        out TfEditCookie pCookie
        );

    uint Push([MarshalAs(UnmanagedType.Interface)] ITfContext pContext);

    uint Pop(uint Flags);

    uint GetTop(out ITfContext Context);

    uint GetBase(out ITfContext Context);

    uint EnumContexts(out IEnumITfContexts EnumContexts);
}

However, instead of receiving a call to my AdviseSink() method, the app crashes and closes from within the call to Push(). If I do not pass an interface for a text store (which is legal), but rather a null when I call CreateContext, then Push() returns fine, as there is no ITextStoreACP.AdviseSink() to call.

I set the project property "Make Assembly COM-Visible" to true. I set the project property "Register for COM interop" to true, though I don't think this is necessary.

Is there anything else I need to do to make my C# class object based upon the ITextStoreACP interface accessible to an external COM object's method for it to use correctly?

The interface I base my TextStore object from is shown next. All methods are implemented in the text store, with at least the default "Method not implemented" exception, so that I can run the code.

    [Guid("28888fe3-c2a0-483a-a3ea-8cb1ce51ff3d")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public interface ITextStoreACP 
{
    uint AdviseSink(
        [MarshalAs(UnmanagedType.Struct)] ref IID Iid, 
        [MarshalAs(UnmanagedType.IUnknown)] object pUnknown, 
        uint Mask
        );

    uint UnadviseSink([MarshalAs(UnmanagedType.IUnknown)] object pUnknown);

    uint RequestLock(uint LockFlags, out uint hrSession);

    uint GetStatus([MarshalAs(UnmanagedType.Struct)] out TS_STATUS TSS);


    uint QueryInsert(long TestStart, long TestEnd, ulong Count, out long ResultStart, out long ResultEnd);

    uint GetSelection(
        ulong Index,
        ulong Count,
        [MarshalAs(UnmanagedType.Struct)] out TS_SELECTION_ACP Selection,
        out ulong Fetched
        );

    uint SetSelection( 
        ulong Count, 
        [MarshalAs(UnmanagedType.Struct)] ref TS_SELECTION_ACP Selection
        );

    uint GetText(
        long Start,
        long End,
        out string Plain,
        ulong PlainReq,
        out ulong PlainRet,
        [MarshalAs(UnmanagedType.Struct)] out TS_RUNINFO RunInfo,
        ulong RunInfoReq,
        out ulong RunInfoRet,
        out long Next
        );

    uint SetText(
        uint Flags,
        long Start,
        long End,
        string Text, // What kind of marshaling should I specify here for "in WCHAR *" types?
        ulong Count,
        [MarshalAs(UnmanagedType.Struct)] out TS_TEXTCHANCE Change
        );

    uint GetFormattedText(
        long Start, 
        long End, 
        [MarshalAs(UnmanagedType.Interface)] out IDataObject DataObject
        );

    uint GetEmbedded(
        long Pos,
        [MarshalAs(UnmanagedType.Struct)] ref IID GUID_Service,
        [MarshalAs(UnmanagedType.Struct)] ref IID IID_Service,
        [MarshalAs(UnmanagedType.IUnknown)] out object pUnk
        );

    uint QueryInsertEmbedded(
        [MarshalAs(UnmanagedType.Struct)] ref IID GUID_Service,
        [MarshalAs(UnmanagedType.Struct)] ref FORMATETC FormatEtc,
        [MarshalAs(UnmanagedType.Bool)] out bool IsInsertable
        );

    uint InsertEmbedded(
        uint Flags,
        long Start,
        long End,
        [MarshalAs(UnmanagedType.Interface)] IDataObject DataObject,
        [MarshalAs(UnmanagedType.Struct)] out TS_TEXTCHANCE Change
        );

    uint InsertTextAtSelection(
        uint Flags,
        string Text,
        ulong Count,
        out long Start,
        out long End,
        [MarshalAs(UnmanagedType.Struct)] out TS_TEXTCHANCE Change
        );

    uint InsertEmbeddedAtSelection(
        uint Flags,
        [MarshalAs(UnmanagedType.Interface)] IDataObject DataObject,
        out long Start,
        out long End,
        [MarshalAs(UnmanagedType.Struct)] out TS_TEXTCHANCE Change
        );

    uint RequestSupportedAttrs(
        uint Flags,
        ulong FilterAttrs,
        [MarshalAs(UnmanagedType.Struct)] ref TS_ATTRID AttrId
        );

    uint RequestAttrsAtPosition(
        long Pos,
        ulong FilterAttrs,
        [MarshalAs(UnmanagedType.Struct)] ref TS_ATTRID AttrId,
        uint Flags
        );

    uint RequestAttrsTransitioningAtPosition(
        long Pos,
        ulong FilterAttrs,
        [MarshalAs(UnmanagedType.Struct)] ref TS_ATTRID AttrId,
        uint Flags
        );

    uint FindNextAttrTransition(
        long Start,
        long Halt,
        ulong FilterAttrs,
        [MarshalAs(UnmanagedType.Struct)] ref TS_ATTRID AttrId,
        uint Flags,
        out long Next,
        out bool Found,
        out long FoundOffset
        );

    uint RetrieveRequestedAttrs(
        ulong Count,
        [MarshalAs(UnmanagedType.Struct)] ref TS_ATTRVAL Vals,
        out ulong Fetched
        );

    uint GetEndACP(out long Acp);

    uint GetActiveView(out TsViewCookie Cookie);

    uint GetACPFromPoint(
        TsViewCookie Cookie,
        [MarshalAs(UnmanagedType.Struct)] ref POINT Point,
        uint Flags,
        out long Acp
        );

    uint GetTextExt(
        TsViewCookie Cookie,
        long Start,
        long End,
        [MarshalAs(UnmanagedType.Struct)] out RECT Rect,
        out bool IsClipped
        );

    uint GetScreenExt(
        TsViewCookie Cookie,
        [MarshalAs(UnmanagedType.Struct)] out RECT Rect
        );

    uint GetWnd(
        TsViewCookie Cookie,
        [MarshalAs(UnmanagedType.I4)] IntPtr hWnd
        );
}

Answer 1

It turns out that I needed the following signature:

[ComVisible(true)]
[Guid("28888fe3-c2a0-483a-a3ea-8cb1ce51ff3d")]
[InterfaceType(ComInterfaceType.InterfaceIsIUnknown)]
public interface ITextStoreACP 
{
    uint AdviseSink(
        ref Guid Iid, 
        [MarshalAs(UnmanagedType.IUnknown)] object pUnknown, 
        uint Mask
        );
    .......
}


public class TextStore : ITextStoreACP
{
    #region ITextStoreACP Members

    public uint AdviseSink(ref Guid Iid, object pUnknown, uint Mask)
    {
        throw new NotImplementedException();
    }
    .....
}

But now I find a read access violation and it appears that the stack pointer is popping 0 on the way back, which seems to indicate that the call itself is still not quite right.

And then I find that I simply need to add [PreserveSig] to the AdviseSink method declaration and all is good....

... or change the uint (HRESULT) to void (no return code). See the links here:

http://msdn.microsoft.com/en-us/library/system.runtime.interopservices.preservesigattribute%28v=VS.90%29.aspx http://social.msdn.microsoft.com/Forums/en-US/clr/thread/a8c2d872-a42e-441a-907b-62d4a05f75ea

Didn't need to hire anyone, just needed a little direction. Thanks all!!! You are awesome!