Powerbuilder WebCam

Question

我使用powerbuilder应用程序中的EZTWAIN从HP扫描仪获取图像。最近我尝试了一个柯达模型（i1120），似乎它不被支持。具体而言，应用程序在扫描过程中会冻结（可能问题与duplex扫描有关）。

您能否推荐您使用过的另一个库，并且可以为您工作，并为可从Powerbuilder使用的TWAIN API提供易于使用的包装？

Answer 1

查看该公司：http://www.data-tech.com/我们使用他们的ImageMan ActiveX套件与PB 10.5，它没有问题。

Answer 2

我有一个与多个库双面扫描类似的问题。解决方案是在使用双面扫描而不是ActiveX组件时直接使用扫描仪界面。大多数库都有一个可以随时启用的选项来使用扫描仪界面。

我目前使用Viscomsoft Scanner Pro ActiveX库。

Answer 3

**object : n_webcam** 
================================================================================ 

forward 
global type nvo_webcam from nonvisualobject 
end type 
end forward 

global type nvo_webcam from nonvisualobject autoinstantiate 
end type 

prototype type 

function ulong capCreateCaptureWindowA (string lpszWindowName, ulong dwStyle, long li_x, long li_y, long nWidth, long nHeight, ulong ParentWin, long nId) LIBRARY 'AVICAP32.DLL' alias for "capCreateCaptureWindowA; ansi" 



Function ulong GetDC (ulong hWnd) Library "user32.dll" 
Function long ReleaseDC (ulong hWnd, ulong hdcr) Library "USER32.DLL" 
Function ulong CreateCompatibleDC (ulong hdc) Library "gdi32.dll" 
Function ulong CreateCompatibleBitmap (ulong hdc, ulong nWidth, ulong nHeight) Library "gdi32.dll" 
Function boolean DeleteDC (ulong hDC) Library "Gdi32.dll" 

Function boolean BitBlt (ulong hdcDest, long nXDest, long nYDest, long nWidth, long nHeight, ulong hdcSrc, long nXSrc, long nYSrc, long dwRop) Library "gdi32.dll" 
Function boolean StretchBlt (ulong hdcDest, long nXOriginDest, long nYOriginDest, long nWidthDest, long nHeightDest, ulong hdcSrc, long nXOriginSrc, longnYOriginSrc, long nWidthSrc, long nHeightSrc, long dwRop) Library "gdi32.dll" 

Function ulong SelectObject (ulong hdc, ulong HGDIOBJ) Library "gdi32.dll" 

Function along GetDIBits (ulong hdc, ulong hbmp, uint uStartScan, uint cScanLines, Ref blob lpvBits, Ref BITMAPINFO lpbi, uint uUsage) Library "gdi32.dll" alias for "GetDIBits" 
Function long GetDIBits (ulong hdc, ulong hbmp, uint uStartScan , uint cScanLines, ulong lpvBits, ref bitmapinfo lpbi, uint uUsage) Library "gdi32.dll" alias for "GetDIBits" 

Subroutine CopyBitmapFileHeader (Blob Ref Destination, bitmapfileheader Source, long Length) Library "kernel32.dll" Alias For "RtlMoveMemory" Subroutine CopyBitmapInfo (Blob Ref Destination, Source bitmapinfo, long Length) Library "kernel32.dll" Alias For "RtlMoveMemory"  


Function boolean OpenClipboard (ulong hWndNewOwner) Library "user32.dll" 
Function boolean CloseClipboard() Library "user32.dll" 
Function boolean EmptyClipboard() Library "user32.dll" 
Function ulong GetClipboardData (ulong uFormat) Library "user32.dll" 

end prototypes 

such variables 
Uint LHand 
Constant long GET_FRAME = 1084 
Constant long COPY = 1054 
Constant long WM_USER = 1024 
Constant long WM_CAP_START = WM_USER 
Constant long WM_CAP_STOP = WM_CAP_START + 68 
Constant long WM_CAP_DRIVER_CONNECT = WM_CAP_START + 10 
Constant long WM_CAP_DRIVER_DISCONNECT = WM_CAP_START + 11 
Constant long WM_CAP_SAVEDIB = WM_CAP_START + 25 
Constant Long WM_CAP_GRAB_FRAME = WM_CAP_START + 60 
Constant LongWM_CAP_SEQUENCE = WM_CAP_START + 62 
Constant long WM_CAP_FILE_SET_CAPTURE_FILEA = WM_CAP_START + 20 
Constant long WM_CAP_FILE_SAVEAS = WM_CAP_START + 23 
Constant long WM_CAP_SEQUENCE_NOFILE = WM_CAP_START + 63 
Constant long WM_CAP_SET_OVERLAY = WM_CAP_START + 51 
Constant long WM_CAP_SET_PREVIEW = WM_CAP_START + 50 
Constant long WM_CAP_SET_CALLBACK_VIDEOSTREAM = WM_CAP_START +6 
Constant long WM_CAP_SET_CALLBACK_ERROR = WM_CAP_START + 2 
Constant Long WM_CAP_SET_CALLBACK_STATUSA = WM_CAP_START +3 
Long Constant WM_CAP_SET_CALLBACK_FRAME = WM_CAP_START +5 
Long Constant WM_CAP_SET_SCALE = WM_CAP_START + 53 
Long Constant WM_CAP_SET_PREVIEWRATE = WM_CAP_START + 52 
end variables 

forward prototypes 
public subroutine of_close() 
public subroutine of_initialize_webcam (unsignedlong a_handle, string a_title, integer a_width, integer a_height) 
public function blob of_copy_clipboard_to_blob() 
public subroutine of_capture_pic() 
end prototypes 

public subroutine of_close(); send (lhand, WM_CAP_DRIVER_DISCONNECT, 0, 0) 
end subroutine 

public subroutine of_initialize_webcam (unsigned long a_handle, string a_title, integer a_width, integer a_height); string lpszName 

lpszName = a_title 
if lhand = 0 then 
lhand = capCreateCaptureWindowA (lpszName, 262144 + 12582912 + 1073741824 + 268435456, 1.40, a_width, a_height, a_handle, 0) 
end if 
if lhand <> 0 then 
send (lhand, WM_CAP_SET_CALLBACK_VIDEOSTREAM, 0, 0) 
send (lhand, WM_CAP_SET_CALLBACK_ERROR, 0, 0) 
send (lhand, WM_CAP_SET_CALLBACK_STATUSA, 0, 0) 

send (lhand, WM_CAP_DRIVER_CONNECT, 0, 0) 
send (lhand, WM_CAP_SET_SCALE, 1, 0) 
send (lhand, WM_CAP_SET_PREVIEWRATE, 66, 0) 
send (lhand, WM_CAP_SET_OVERLAY, 1, 0) 
send (lhand, WM_CAP_SET_PREVIEW, 1, 0) 
end if 
end subroutine 

public function blob of_copy_clipboard_to_blob(); BitmapInfo lstr_Info 
BitmapFileHeader lstr_Header 
Blob lblb_header, lblb_info, lblb_bitmap, lbl_final 
ULong lul_hdc, lul_hdcMem, lul_hBitmap, lul_hWnd, lul_blpos 
UInt DIB_RGB_COLORS 
Integer li_pixels 
Boolean lb_result 
long al_width, ll_height, ll_ret 

constant integer BITMAPTYPE = 19778 // 4D42 = BM 
constant integer CF_BITMAP = 2 
constant integer CF_DIB = 8 

lul_hWnd = Handle (this) 
lb_result = OpenClipboard (lul_hWnd) 

// Get the device context and allocate memory 
lul_hdc = GetDC (lul_hWnd) 
lul_hdcMem = CreateCompatibleDC (lul_hdc) 
lul_hBitmap = getclipboarddata (CF_BITMAP) 

// try to store the bitmap into a blob so we can save it 
lstr_Info.bmiHeader.biSize = 40 
ll_height = 480 // ... 480 should be enough for everyone? ;) 
DIB_RGB_COLORS = 0 
// Get the bitmapinfo 
If GetDIBits (lul_hdcMem, lul_hBitmap, 0, ll_height, 0, lstr_Info, DIB_RGB_COLORS)> 0 Then 
li_pixels = lstr_Info.bmiHeader.biBitCount 
lstr_Info.bmiColors [li_pixels] = 0 
lblb_bitmap = Blob (Space (lstr_Info.bmiHeader.biSizeImage), EncodingANSI!) 
ll_height = lstr_Info.bmiHeader.biheight 
// get the actual bits 
ll_ret = GetDIBits (lul_hdcMem, lul_hBitmap, 0, ll_height, lblb_bitmap, lstr_Info, DIB_RGB_COLORS) 
// ls_msg = hexdump_blob (lblb_bitmap, false) 
// create a bitmap header 
lstr_Header.bfType = BITMAPTYPE 
lstr_Header.bfSize = lstr_Info.bmiHeader.biSizeImage 
lstr_Header.bfOffBits = 54 + (li_pixels * 4) 
// copy the header structure to a blob 
lblb_header = Blob (Space (7)) // 
14/2 CopyBitmapFileHeader (lblb_header, lstr_Header, 14) 
// copy the info structure to a blob 
lblb_Info = Blob (Space (40 + li_pixels * 4)/2)) 
CopyBitmapInfo (lblb_Info, lstr_Info, len (lblb_Info)) 
// add all together and we have a window bitmap in a blob 
lbl_final = lblb_header + lblb_info + lblb_bitmap 
End If 

CloseClipboard() 
ReleaseDC (lul_hwnd, lul_hdc) 
DeleteDC (lul_hdcMem) 

return lbl_final 
end function 

public subroutine of_capture_pic(); Send (lhand, GET_FRAME, 0, 0) 
Send (lhand, COPY, 0, 0) 


end subroutine 

we have nvo_webcam. create 
call super :: create 
TriggerEvent (this , "constructor") 
end on 

we have nvo_webcam. destroy 
TriggerEvent (this , "destructor") 
call super :: destroy 
end on 

**instantiate the object and initialize it:** 
================================================================================ 

n_webcam.of_initialize_webcam (handle (this), "Webcam" , il_width, il_height) 

**capture:** 
================================================================================ 

n_webcam.of_capture_pic() 

**image processing:** 
================================================================================ 

lb_blob = n_webcam..of_copy_clipboard_to_blob() 
// reinitialize for the webcam to continue live 
i_nvo_webcam.of_initialize_webcam (handle (this), "Webcam" , il_width, il_height) 

**Close:** 
================================================================================ 

n_webcam.of_close() 

观看视频https://youtu.be/ojcJs1ajWRc