シェルの縮小イメージの取得

#pragma once

#include "ILHelper.h"

_COM_SMARTPTR_TYPEDEF(IExtractImage,    __uuidof(IExtractImage));

/////////////////////////////////////////////////////////////////////////////

// CExtractImageHelper

class CExtractImageHelper

{

protected:

    CExtractImageHelper();                // 実装しない

    virtual ~CExtractImageHelper();

public:

    // 完成

    static HBITMAP GetImage(HWND hWnd, IShellFolderPtr spShellFolder, LPCITEMIDLIST pidl, const CSize& size, DWORD dwDepth = 32)

    {

        if (spShellFolder == NULL || pidl == NULL)

        {

            return NULL;

        }

        HRESULT hr = S_OK;

        IExtractImagePtr spExtractImage;

        hr = spShellFolder->GetUIObjectOf(hWnd, 1, &pidl, IID_IExtractImage, NULL, (void**)&spExtractImage);

        if (FAILED(hr))

        {

            return NULL;

        }

        return GetImage(spExtractImage, size, dwDepth);

    }

    // 完成

    // ショートカットや共有フォルダのイメージは未対応。。

    static HBITMAP GetImage(IExtractImagePtr spExtractImage, const CSize& size, DWORD dwDepth = 32)

    {

        if (spExtractImage == NULL)

        {

            return NULL;

        }

        HRESULT hr = S_OK;

        OLECHAR wszPathBuffer[MAX_PATH];

        DWORD dwPriority = 0;                // IEI_PRIORITY_NORMAL is defined nowhere!

        DWORD dwFlags = IEIFLAG_SCREEN;

        hr = spExtractImage->GetLocation(wszPathBuffer, MAX_PATH, &dwPriority, &size, dwDepth, &dwFlags);

        if (FAILED(hr))

        {

            return NULL;

        }

        HBITMAP hBitmap = NULL;

        hr = spExtractImage->Extract(&hBitmap);

        if (FAILED(hr))

        {

            return NULL;

        }

        return hBitmap;

    }

    // pidlは、フルバージョンを入れる必要あり。。

    static HBITMAP GetImageFromIcon(HWND hWnd, LPCITEMIDLIST pidl, const CSize& size, DWORD dwDepth = 32)

    {

        if (pidl == NULL)

        {

            return NULL;

        }

        SHFILEINFO info;

        ZeroMemory(&info, sizeof(info));

        UINT uFlags = SHGFI_PIDL | SHGFI_ICON | SHGFI_LARGEICON | SHGFI_SYSICONINDEX;

        HIMAGELIST hImageList = (HIMAGELIST)::SHGetFileInfo((LPCSTR)pidl, 0, &info, sizeof(info), uFlags);

        HICON hIcon = ::ImageList_GetIcon(hImageList, info.iIcon, ILD_TRANSPARENT);

        HDC hDC = ::GetDC(hWnd);

        HDC hMemDC = ::CreateCompatibleDC(hDC);

        HBITMAP hBitmap = (HBITMAP)::CreateCompatibleBitmap(hDC, size.cx, size.cy);

        HBITMAP hOldBitmap = (HBITMAP)::SelectObject(hMemDC, (HBITMAP)hBitmap);

        ::FillRect(hMemDC, CRect(0, 0, size.cx, size.cy), ::GetSysColorBrush(COLOR_WINDOW));

        ::DrawIcon(hMemDC, (size.cx - 32) / 2, (size.cy - 32) / 2, hIcon);

//        ::FrameRect(hMemDC, CRect(0, 0, size.cx, size.cy ), ::GetSysColorBrush(COLOR_BTNSHADOW));

        ::SelectObject(hMemDC, hOldBitmap);

        ::DeleteDC(hMemDC);

        ::DeleteDC(hDC);

        return hBitmap;

    }

public:

/*

    // 完成

    static HBITMAP ExtractThumb(LPSHELLFOLDER psfFolder, LPCITEMIDLIST localPidl, const SIZE* prgSize, DWORD dwRecClrDepth)

    {

        LPEXTRACTIMAGE pIExtract = NULL;

        HRESULT hr;

        hr = psfFolder->GetUIObjectOf(NULL, 1, &localPidl, IID_IExtractImage,

            NULL, (void**)&pIExtract);

        if(NULL == pIExtract) // early shell version, thumbs not supported

            return NULL;

        OLECHAR wszPathBuffer[MAX_PATH];

        DWORD dwPriority = 0; // IEI_PRIORITY_NORMAL is defined nowhere!

        DWORD dwFlags = IEIFLAG_SCREEN;

        HBITMAP hBmpImage = NULL;

        hr = pIExtract->GetLocation(wszPathBuffer, MAX_PATH, &dwPriority,

            prgSize, dwRecClrDepth, &dwFlags);

        // even if we've got shell v4.70+, not all files support thumbnails 

        if(NOERROR == hr)

            hr = pIExtract->Extract(&hBmpImage);

        pIExtract->Release();

        return hBmpImage; // callers should DeleteObject this handle after use

    }

*/

};