L_CaptureWindow

#include "l_bitmap.h"

L_INT EXT_FUNCTION L_CaptureWindow(pBitmap, uBitmapStructSize, hWnd, wctCaptureType, pCaptureInfo, uInfoStructSize, pfnCaptureCallback,pUserData)

pBITMAPHANDLE pBitmap;	/* pointer to the bitmap handle */
L_UINT uBitmapStructSize;	/* size in bytes, of pBitmap */
HWND hWnd;	/* window handle */
WINDOWCAPTURETYPE wctCaptureType;	/* flag */
pLEADCAPTUREINFO pCaptureInfo;	/* pointer to info structure */
L_UINT uInfoStructSize;	/* size in bytes, of the structure pointed to by pCaptureInfo */
CAPTURECALLBACK pfnCaptureCallback;	/* optional callback function */
L_VOID * pUserData;	/* pointer to more parameters for the callback */

Captures an image of a window handle.

Parameter	Description
pBitmap	Pointer to a bitmap handle that references the captured data.
uBitmapStructSize	Size in bytes, of the structure pointed to by pBitmap, for versioning. Use sizeof (BITMAPHANDLE).
hWnd	Handle of the window to capture.
wctCaptureType	Flag that indicates the capture type. Possible values are:
	Value	Meaning
	CAPTURE_CLIENT_AREA	[0x01] Captures the client area of the window.
	CAPTURE_WINDOW	[0x02] Captures the complete window.
pCaptureInfo	Pointer to the LEADCAPTUREINFO structure to be updated with information regarding the captured image's source. Pass NULL if you are not interested in extra information about the capture.
uInfoStructSize	Size in bytes, of the structure pointed to by pCaptureInfo, for versioning. Use sizeof (LEADCAPTURE).
pfnCaptureCallback	Optional callback function for additional processing. If you do not provide a callback function, use NULL as the value of this parameter. If you do provide a callback function, use the function pointer as the value of this parameter. The callback function must adhere to the function prototype described in CAPTURECALLBACK Function.
pUserData	Void pointer that you can use to pass one or more additional parameters that the callback function needs. To use this feature, assign a value to a variable or create a structure that contains as many fields as you need. Then, in this parameter, pass the address of the variable or structure, casting it to L_VOID ;. The callback function, which receives the address in its own pUserData* parameter, can cast it to a pointer of the appropriate data type to access your variable or structure. If the additional parameters are not needed, you can pass NULL in this parameter.

Returns

SUCCESS	The function was successful.
< 1	An error occurred. Refer to Return Codes.

Comments

The callback can be used to do multiple captures, depending on the options set using L_SetCaptureOption.

Required DLLs and Libraries

LTSCR

For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.

Platforms

Windows 95 / 98 / Me, Windows 2000 / XP, Windows CE.

See Also

Functions:	L_SetCaptureOption, L_SetCaptureOptionDlg, CAPTURECALLBACK, L_StopCapture
Topics:	Capture Functions
	Implementing Screen Capture

Example

static L_INT EXT_CALLBACK pfnCaptureCallback(pBITMAPHANDLE pBitmap, pLEADCAPTUREINFO pCaptureInfo, L_VOID* pUserData)
{
   UNREFERENCED_PARAMETER(pCaptureInfo);
   UNREFERENCED_PARAMETER(pUserData);

   /* save the captured image */
   Return (L_SaveBitmap (TEXT("C:\\Program Files\\LEAD Technologies, Inc\\LEADTOOLS 14.5\\Images\\test.bmp"), pBitmap, FILE_BMP, 0, 0, NULL));
}

L_INT CaptureWindowExample (L_VOID)
{
   BITMAPHANDLE    Bitmap;
   LEADCAPTUREINFO CaptureInfo;

   /* Get the window handle */
   HWND hWnd = GetForegroundWindow();

   /* To call the L_CaptureWindow */
   L_INT nRet = L_CaptureWindow(&Bitmap, sizeof(BITMAPHANDLE), hWnd, CAPTURE_WINDOW, &CaptureInfo, sizeof(LEADCAPTUREINFO), pfnCaptureCallback, NULL);

    L_FreeBitmap (&Bitmap);
   return nRet;
}