You want to implement IExtractImage or IExtractImage2 and register it as a Windows Shell extension!Simply implement IExtractImage2, this is required to provide the date stamp for your thumbnails thumbnails. The operating system only uses IExtractImage2 if it has been confirmed that your application knows this interface. So far so good! Now to IExtractImage! IExtractImage2 implements all IExtractImage methods and always the basic interface IUnknown. The IExtractImage interface requests an image of an object, for example an object in a shell folder. You can also implement IExtractImage alone if your namespace extension has to provide thumbnails that should be displayed in a shell view and the date stamp from the IExtractImage2 interface does not play a major role. TIP: Use IExtractImage instead of IExtractImage2 anyway, is better! Optionally, the IThumbnailCache interface from Vista to Windows 10, several image formats are also supported! #ifndef __IExtractImage_FWD_DEFINED__ #define __IExtractImage_FWD_DEFINED__ //BB2E617C-0920-11d1-9A0B-00C04FC2D6C1 DEFINE_GUID(IID_IExtractImage, 0xBB2E617C, 0x0920, 0x11d1, 0x9A, 0x0B, 0x00, 0xC0, 0x4F, 0xC2, 0xD6, 0xC1); #define IEI_PRIORITY_MAX ITSAT_MAX_PRIORITY #define IEI_PRIORITY_MIN ITSAT_MIN_PRIORITY #define IEIT_PRIORITY_NORMAL ITSAT_DEFAULT_PRIORITY #define IEIFLAG_ASYNC 0x0001 // (deprecated) ask the extractor if it supports ASYNC extract (free threaded) #define IEIFLAG_CACHE 0x0002 // returned from the extractor if it does NOT cache the thumbnail #define IEIFLAG_ASPECT 0x0004 // passed to the extractor to beg it to render to the aspect ratio of the supplied rect #define IEIFLAG_OFFLINE 0x0008 // if the extractor shouldn't hit the net to get any content neede for the rendering #define IEIFLAG_GLEAM 0x0010 // does the image have a gleam ? this will be returned if it does #define IEIFLAG_SCREEN 0x0020 // render as if for the screen (this is exlusive with IEIFLAG_ASPECT ) #define IEIFLAG_ORIGSIZE 0x0040 // render to the approx size passed, but crop if neccessary #define IEIFLAG_NOSTAMP 0x0080 // returned from the extractor if it does NOT want an icon stamp on the thumbnail #define IEIFLAG_NOBORDER 0x0100 // returned from the extractor if it does NOT want an a border around the thumbnail #define IEIFLAG_QUALITY 0x0200 // passed to the Extract method to indicate that a slower, higher quality image is desired, re-compute the thumbnaile #define IEIFLAG_REFRESH 0x0400
// returned from the extractor if it would like to have Refresh Thumbnail available //#if defined(__cplusplus) && !defined(CINTERFACE) MIDL_INTERFACE("BB2E617C-0920-11d1-9A0B-00C04FC2D6C1") IExtractImage : public IUnknown { public: virtual HRESULT STDMETHODCALLTYPE GetLocation( /* [size_is][out] */ LPWSTR pszPathBuffer, /* [in] */ DWORD cch, /* [unique][out][in] */ DWORD *pdwPriority, /* [in] */ const SIZE *prgSize, /* [in] */ DWORD dwRecClrDepth, /* [in] */ DWORD *pdwFlags) = 0; virtual HRESULT STDMETHODCALLTYPE Extract( /* [out] */ HBITMAP *phBmpThumbnail) = 0; }; DEFINE_GUID(IID_IExtractImage2, 0x953BB1EE, 0x93B4, 0x11d1, 0x98, 0xA3, 0x00, 0xC0, 0x4F, 0xB6, 0x87, 0xDA); MIDL_INTERFACE("953BB1EE-93B4-11d1-98A3-00C04FB687DA") IExtractImage2 : public IExtractImage { public: virtual HRESULT STDMETHODCALLTYPE GetDateStamp( /* [out] */ FILETIME *pDateStamp) = 0; }; #endif FAQ 11: Updated on: 16 May 2020 09:26 |
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