IAttachmentExecute interface

Exposes methods that work with client applications to present a user environment that provides safe download and exchange of files through email and messaging attachments.

Methods

The IAttachmentExecute interface has these methods.

Method Description
IAttachmentExecute::CheckPolicy Provides a Boolean test that can be used to make decisions based on the attachment's execution policy.
IAttachmentExecute::ClearClientState Removes any stored state that is based on the client's GUID. An example might be a setting based on a checked box that indicates a prompt should not be displayed again for a particular file type.
IAttachmentExecute::Execute Executes an action on an attachment.
IAttachmentExecute::Prompt Presents a prompt UI to the user.
IAttachmentExecute::Save Saves the attachment.
IAttachmentExecute::SaveWithUI Presents the user with explanatory error UI if the save action fails.
IAttachmentExecute::SetClientGuid Specifies and stores the GUID for the client.
IAttachmentExecute::SetClientTitle Specifies and stores the title of the prompt window.
IAttachmentExecute::SetFileName Specifies and stores the proposed name of the file.
IAttachmentExecute::SetLocalPath Sets and stores the path to the file.
IAttachmentExecute::SetReferrer Sets the security zone associated with the attachment file based on the referring file.
IAttachmentExecute::SetSource Sets an alternate path or URL for the source of a file transfer.

Remarks

This interface assumes the following:

  • The client has policies or settings for attachment support and behavior.
  • The client interacts with the user.
The IID for this interface is IID_IAttachmentExecute.

Here is an example of how an email client might use IAttachmentExecute.


// CClientAttachmentInfo, defined by the client, implements all the
// necessary client functionality concerning attachments. 
class CClientAttachmentInfo;  

// Creates an instance of IAttachmentExecute
HRESULT CreateAttachmentServices(IAttachmentExecute **ppae)
{
    // Assume that CoInitialize has already been called for this thread.
    HRESULT hr = CoCreateInstance(CLSID_AttachmentServices, 
                                  NULL, 
                                  CLSCTX_INPROC_SERVER, 
                                  IID_IAttachmentExecute, 
                                  (void**)&pAttachExec);

    if (SUCCEEDED(hr))
    {
        // Set the client's GUID.

        // UUID_ClientID should be created using uuidgen.exe and 
        // defined internally.
        (*ppae)->SetClientGuid(UUID_ClientID);
        
        // You also could call SetClientTitle at this point, but it is
        // not required.
    }
    return hr;
}

BOOL IsAttachmentBlocked(CClientAttachmentInfo *pinfo)
{
    // Assume that a client function has copied the file from the mail store 
    // into a temporary file.
    PWSTR pszFileName;

    // GetFileName is a method in this class for which we do not provide
    // an implementation here.
    HRESULT hr = pinfo->GetFileName(&pszFileName);
    if (SUCCEEDED(hr))
    {
        IAttachmentExecute *pExecute;

        hr = CreateAttachmentServices(&pExecute);
        if (SUCCEEDED(hr))
        {
            hr = pExecute->SetFileName(pszFileName);

            // Do not call SetLocalPath since we do not have the local path yet.
            // Do not call SetSource since email sources are not verifiable.
            // Do not call SetReferrer since we do not have a better zone 
            // than the default (Restricted sites).

            // Check for a policy regarding the file.
            if (SUCCEEDED(hr))
            {
                hr = pExecute->CheckPolicy();
            }
            pExecute->Release();
        }
        LocalFree(pszFileName);
    }
    return FAILED(hr);
}
    
HRESULT OnDoubleClickAttachment(HWND hwnd, CClientAttachmentInfo *pinfo)
{
    // Assume that a client function has copied the file from the mail store 
    // into a temporary file.
    PWSTR pszTempFile;

    // CopyToTempFile is a method in this class for which we do not provide
    // an implementation here.
    HRESULT hr = pinfo->CopyToTempFile(&pszTempFile);
    if (SUCCEEDED(hr))
    {
        IAttachmentExecute *pExecute;

        hr = CreateAttachmentServices(&pExecute);
        if (SUCCEEDED(hr))
        {
            hr = pExecute->SetLocalPath(pszTempFile);

            // Do not call SetFileName since we already have the local path.
            // Do not call SetSource since email sources are not verifiable.
            // Do not call SetReferrer since we do not have a better zone 
            // than the default (Restricted sites).

            if (SUCCEEDED(hr))
            {
                hr = pExecute->Execute(hwnd, NULL, NULL);
            }
            pExecute->Release();
        }
        LocalFree(pszTempFile);
    }
    return hr;
}

HRESULT OnSaveAttachment(HWND hwnd, CClientAttachmentInfo *pinfo)
{
    // Assume that a client function has copied the file from the mail store 
    // into a location selected by the user.
    PWSTR pszUserFile;

    // CopyToUserFile is a method in this class for which we do not provide
    // an implementation here.
    HRESULT hr = pinfo->CopyToUserFile(hwnd, &pszUserFile);
    if (SUCCEEDED(hr))
    {
        IAttachmentExecute *pExecute;

        hr = CreateAttachmentServices(&pExecute);
        if (SUCCEEDED(hr))
        {
            hr = pExecute->SetLocalPath(pszTempFile);

            // Do not call SetFileName since we have the local path.
            // Do not call SetSource since email sources are not verifiable.
            // Do not call SetReferrer since we do not have a better zone 
            // than the default (Restricted sites).

            if (SUCCEEDED(hr))
            {
                hr = pExecute->Save();
            }
            pExecute->Release();
        }
        LocalFree(pszUserFile);
    }
    return hr;
}

Requirements

   
Minimum supported client Windows XP with SP2 [desktop apps only]
Minimum supported server Windows Server 2003 [desktop apps only]
Target Platform Windows
Header shobjidl_core.h