关于LoadImage

要写一个位图播放软件demo，用定时器每隔100ms从硬盘中读取一副位图然后显示，所以用API LoadImage从硬盘中读取位图，函数调用如下

HBITMAP bmp = (HBITMAP)LoadImage(NULL, strFileName.GetBuffer(), IMAGE_BITMAP, 0, 0, LR_CREATEDIBSECTION | LR_LOADFROMFILE);

结果定时器计数到50~60次时，动画便停止。

本来以为是定时器被堵死，无法响应中断，然后尝试将文件放到内存中直接显示，结果问题还是存在。

然后单步调试跟踪发现是LoadImage在执行了50~60次以后载入位图出错，bmp地址为0x00000000，参阅MSDN

LoadImage

LoadImage

The LoadImage function loads an icon, cursor, animated cursor, or bitmap.

HANDLE LoadImage(  HINSTANCE hinst,   // handle to instance  LPCTSTR lpszName,  // image to load  UINT uType,        // image type  int cxDesired,     // desired width  int cyDesired,     // desired height  UINT fuLoad        // load options);

Parameters

hinst

[in] Handle to an instance of the module that contains the image to be loaded. To load an OEM image, set this parameter to zero.

lpszName

[in] Specifies the image to load. If the hinst parameter is non-NULL and the fuLoad parameter omits LR_LOADFROMFILE, lpszName specifies the image resource in the hinst module. If the image resource is to be loaded by name, the lpszName parameter is a pointer to a null-terminated string that contains the name of the image resource. If the image resource is to be loaded by ordinal, use the MAKEINTRESOURCE macro to convert the image ordinal into a form that can be passed to the LoadImage function.

If the hinst parameter is NULL and the fuLoad parameter omits the LR_LOADFROMFILE value, the lpszName specifies the OEM image to load. The OEM image identifiers are defined in Winuser.h and have the following prefixes. PrefixMeaningOBM_OEM bitmapsOIC_OEM iconsOCR_OEM cursors

To pass these constants to the LoadImage function, use the MAKEINTRESOURCE macro. For example, to load the OCR_NORMAL cursor, pass MAKEINTRESOURCE(OCR_NORMAL) as the lpszName parameter and NULL as the hinst parameter.

If the fuLoad parameter includes the LR_LOADFROMFILE value, lpszName is the name of the file that contains the image.

uType

[in] Specifies the type of image to be loaded. This parameter can be one of the following values. ValueMeaningIMAGE_BITMAPLoads a bitmap.IMAGE_CURSORLoads a cursor.IMAGE_ICONLoads an icon.

cxDesired

[in] Specifies the width, in pixels, of the icon or cursor. If this parameter is zero and the fuLoad parameter is LR_DEFAULTSIZE, the function uses the SM_CXICON or SM_CXCURSOR system metric value to set the width. If this parameter is zero and LR_DEFAULTSIZE is not used, the function uses the actual resource width.

cyDesired

[in] Specifies the height, in pixels, of the icon or cursor. If this parameter is zero and the fuLoad parameter is LR_DEFAULTSIZE, the function uses the SM_CYICON or SM_CYCURSOR system metric value to set the height. If this parameter is zero and LR_DEFAULTSIZE is not used, the function uses the actual resource height.

fuLoad

[in] This parameter can be one or more of the following values. ValueMeaningLR_DEFAULTCOLORThe default flag; it does nothing. All it means is "not LR_MONOCHROME".LR_CREATEDIBSECTIONWhen the uType parameter specifies IMAGE_BITMAP, causes the function to return a DIB section bitmap rather than a compatible bitmap. This flag is useful for loading a bitmap without mapping it to the colors of the display device.LR_DEFAULTSIZEUses the width or height specified by the system metric values for cursors or icons, if the cxDesired or cyDesired values are set to zero. If this flag is not specified and cxDesired and cyDesired are set to zero, the function uses the actual resource size. If the resource contains multiple images, the function uses the size of the first image. LR_LOADFROMFILELoads the image from the file specified by the lpszName parameter. If this flag is not specified, lpszName is the name of the resource.LR_LOADMAP3DCOLORSSearches the color table for the image and replaces the following shades of gray with the corresponding 3-D color: ColorReplaced with Dk Gray,
RGB(128,128,128)COLOR_3DSHADOW Gray,
RGB(192,192,192)COLOR_3DFACE Lt Gray,
RGB(223,223,223)COLOR_3DLIGHT Do not use this option if you are loading a bitmap with a color depth greater than 8bpp.LR_LOADTRANSPARENTRetrieves the color value of the first pixel in the image and replaces the corresponding entry in the color table with the default window color (COLOR_WINDOW). All pixels in the image that use that entry become the default window color. This value applies only to images that have corresponding color tables.

Do not use this option if you are loading a bitmap with a color depth greater than 8bpp.

If fuLoad includes both the LR_LOADTRANSPARENT and LR_LOADMAP3DCOLORS values, LRLOADTRANSPARENT takes precedence. However, the color table entry is replaced with COLOR_3DFACE rather than COLOR_WINDOW.

LR_MONOCHROMELoads the image in black and white.LR_SHAREDShares the image handle if the image is loaded multiple times. If LR_SHARED is not set, a second call to LoadImage for the same resource will load the image again and return a different handle.

When you use this flag, the system will destroy the resource when it is no longer needed.

Do not use LR_SHARED for images that have non-standard sizes, that may change after loading, or that are loaded from a file.

When loading a system icon or cursor, you must use LR_SHARED or the function will fail to load the resource.

Windows 95/98/Me: The function finds the first image with the requested resource name in the cache, regardless of the size requested.

LR_VGACOLORUses true VGA colors.

当加载OEM位图，并且fuLoad为LR_LOADFROMFILE，hinst可以等于NULL，所以将函数调用修改为

HBITMAP bmp = (HBITMAP)LoadImage(AfxGetInstanceHandle(), strFileName.GetBuffer(), IMAGE_BITMAP, 0, 0, LR_CREATEDIBSECTION | LR_LOADFROMFILE);

一切OK。但是问题是能够正常运行一段时间，然后动画终止？