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: |
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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; }