L_CaptureWindow

#include "l_bitmap.h"

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

pBITMAPHANDLE pBitmap;	/* pointer to the bitmap handle */
L_UINT uBitmapStructSize;	/* size, in bytes, of the structure */
HWND hWnd;	/* window handle */
WINDOWCAPTURETYPE wctCaptureType;	/* flag */
pLEADCAPTUREINFO pCaptureInfo;	/* pointer to info structure */
L_UINT uInfoStructSize;	/* size, in bytes, of the structure/
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	Value that represents the size, in bytes, of the structure pointed to by pBitmap parameter, 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] Capture 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	Value that represents the size, in bytes, of the structure pointed to by pCaptureInfo parameter, for versioning. Use sizeof(LEADCAPTUREINFO).
pfnCaptureCallback	Optional callback function for additional processing. If you do not provide a callback function, pass NULL as the value of this parameter. If you do provide a callback function, pass 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 function.

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.

See Also

Functions:	L_SetCaptureOption, L_SetCaptureOptionDlg, CAPTURECALLBACK, L_StopCapture
Topics:	Screen Capture API Function Groups: 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;
}