HANDLE IMAPI ImgXBeginWriteMem (lpszExt, lpDIB, hOptBlk, lpInfo, hMemBlk, dwUsed)

This function is used to begin exporting an image to a memory block.

 

Parameter	Type	Description
lpszExt	LPCSTR	Points to a string which identifies the extension of the file type to use for writing this image (i.e., TIF).
lpDIB	LPBITMAPINFO	Points to a BITMAPINFO struct which defines the image.
hOptBlk	HANDLE	Handle to an option block for this image. If this is NULL, ImageMan will assume logical defaults.
lpInfo	LPXINFO	Points to an XINFO struct defining the export procedure for this image.
hMemBlk	HPSTR	Globally Allocated memory block to write the image into. If this is NULL, a memory block will be allocated.
dwUsed	DWORD	Offset of first byte to begin writing image into in hMemBlk.

 

Return Value

The return value is the handle to use when referencing this export job in future ImageMan functions; it is NULL if an error occurred.

Comments

This is the function which initiates the export of an image to a memory buffer. Before calling this function, you should create an OptBlk with the desired options (or leave this NULL), Fill in the XINFO struct pointed to by lpInfo with the desired values, and determine the type of file you will be exporting.

 

ImageMan will resize hMemBlk as needed during the export process, so it is important that hMemBlk be a globally allocated memory block which can be resized.

Note

If ImageMan is forced to reallocated hMemBlk, the value for hMemBlk could potentially be altered. It is therefore amazingly important that your application pay attention to the memory block returned from ImgXEndWriteMem, as that will be the new handle value. The original handle value will no longer be valid!

 

 

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