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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.

Members

The IAttachmentExecute interface inherits from the IUnknown interface. IAttachmentExecute also has these types of members:

Methods

The IAttachmentExecute interface has these methods.

MethodDescription
CheckPolicy

Provides a Boolean test that can be used to make decisions based on the attachment's execution policy.

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.

Execute

Executes an action on an attachment.

Prompt

Presents a prompt UI to the user.

Save

Saves the attachment.

SaveWithUI

Presents the user with explanatory error UI if the save action fails.

SetClientGuid

Specifies and stores the GUID for the client.

SetClientTitle

Specifies and stores the title of the prompt window.

SetFileName

Specifies and stores the proposed name of the file.

SetLocalPath

Sets and stores the path to the file.

SetReferrer

Sets the security zone associated with the attachment file based on the referring file.

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]

DLL

Shdocvw.dll

 

 

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