simpleshlext.cpp

Windows Shell扩展编程完全指南

// SimpleShlExt.cpp : Implementation of CSimpleShlExt

#include "stdafx.h"
#include "resource.h"
#include "SimpleExt.h"
#include "SimpleShlExt.h"

/////////////////////////////////////////////////////////////////////////////
// CSimpleShlExt

STDMETHODIMP CSimpleShlExt::Initialize (
    LPCITEMIDLIST pidlFolder, LPDATAOBJECT pDataObj, HKEY hProgID )
{
FORMATETC fmt = { CF_HDROP, NULL, DVASPECT_CONTENT, -1, TYMED_HGLOBAL };
STGMEDIUM stg = { TYMED_HGLOBAL };
HDROP     hDrop;

    // Look for CF_HDROP data in the data object.
    if ( FAILED( pDataObj->GetData ( &fmt, &stg ) ))
        {
        // Nope! Return an "invalid argument" error back to Explorer.
        return E_INVALIDARG;
        }

    // Get a pointer to the actual data.
    hDrop = (HDROP) GlobalLock ( stg.hGlobal );

    // Make sure it worked.
    if ( NULL == hDrop )
        return E_INVALIDARG;

    // Sanity check - make sure there is at least one filename.
UINT uNumFiles = DragQueryFile ( hDrop, 0xFFFFFFFF, NULL, 0 );
HRESULT hr = S_OK;

    if ( 0 == uNumFiles )
        {
        GlobalUnlock ( stg.hGlobal );
        ReleaseStgMedium ( &stg );
        return E_INVALIDARG;
        }

    // Get the name of the first file and store it in our member variable m_szFile.
    if ( 0 == DragQueryFile ( hDrop, 0, m_szFile, MAX_PATH ) )
        hr = E_INVALIDARG;

    GlobalUnlock ( stg.hGlobal );
    ReleaseStgMedium ( &stg );

    return hr;
}

STDMETHODIMP CSimpleShlExt::QueryContextMenu (
    HMENU hmenu, UINT uMenuIndex, UINT uidFirstCmd,
    UINT uidLastCmd, UINT uFlags )
{
    // If the flags include CMF_DEFAULTONLY then we shouldn't do anything.
    if ( uFlags & CMF_DEFAULTONLY )
        return MAKE_HRESULT ( SEVERITY_SUCCESS, FACILITY_NULL, 0 );

    InsertMenu ( hmenu, uMenuIndex, MF_BYPOSITION, uidFirstCmd, _T("SimpleShlExt Test Item") );

    return MAKE_HRESULT ( SEVERITY_SUCCESS, FACILITY_NULL, 1 );
}

STDMETHODIMP CSimpleShlExt::GetCommandString (
    UINT idCmd, UINT uFlags, UINT* pwReserved, LPSTR pszName, UINT cchMax )
{
USES_CONVERSION;

    // Check idCmd, it must be 0 since we have only one menu item.
    if ( 0 != idCmd )
        return E_INVALIDARG;

    // If Explorer is asking for a help string, copy our string into the
    // supplied buffer.
    if ( uFlags & GCS_HELPTEXT )
        {
        LPCTSTR szText = _T("This is the simple shell extension's help");

        if ( uFlags & GCS_UNICODE )
            {
            // We need to cast pszName to a Unicode string, and then use the
            // Unicode string copy API.
            lstrcpynW ( (LPWSTR) pszName, T2CW(szText), cchMax );
            }
        else
            {
            // Use the ANSI string copy API to return the help string.
            lstrcpynA ( pszName, T2CA(szText), cchMax );
            }

        return S_OK;
        }

    return E_INVALIDARG;
}

STDMETHODIMP CSimpleShlExt::InvokeCommand ( LPCMINVOKECOMMANDINFO pCmdInfo )
{
    // If lpVerb really points to a string, ignore this function call and bail out.
    if ( 0 != HIWORD( pCmdInfo->lpVerb ) )
        return E_INVALIDARG;

    // Get the command index - the only valid one is 0.
    switch ( LOWORD( pCmdInfo->lpVerb) )
        {
        case 0:
            {
            TCHAR szMsg [MAX_PATH + 32];

            wsprintf ( szMsg, _T("The selected file was:\n\n%s"), m_szFile );

            MessageBox ( pCmdInfo->hwnd, szMsg, _T("SimpleShlExt"),
                         MB_ICONINFORMATION );

            return S_OK;
            }
        break;

        default:
            return E_INVALIDARG;
        break;
        }
}