[ Show ]
Support VoyForums
[ Shrink ]
VoyForums Announcement: Programming and providing support for this service has been a labor of love since 1997. We are one of the few services online who values our users' privacy, and have never sold your information. We have even fought hard to defend your privacy in legal cases; however, we've done it with almost no financial support -- paying out of pocket to continue providing the service. Due to the issues imposed on us by advertisers, we also stopped hosting most ads on the forums many years ago. We hope you appreciate our efforts.

Show your support by donating any amount. (Note: We are still technically a for-profit company, so your contribution is not tax-deductible.) PayPal Acct: Feedback:

Donate to VoyForums (PayPal):

Login ] [ Contact Forum Admin ] [ Main index ] [ Post a new message ] [ Search | Check update time | Archives: 12[3]45678910 ]

[ Next Thread | Previous Thread | Next Message | Previous Message ]

Date Posted: 11:29:28 05/02/03 Fri
Author: Don
Subject: Re: Testing Envision Image Library C Builder
In reply to: Michel 's message, "Re: Testing Envision Image Library C Builder" on 18:33:39 05/01/03 Thu


So are you saying that I can create and use my own method of passing parameters and defining the OnAcquire event?
Also can I control other Scanner parameters such as contrast, brightness, landscape, etc.. ?

>Hi Don,
>I do not have a CBuilder demo complete like the
>example program. Usually the port from C++ to Object
>Pascal is quite straight forward, replacing
>TObject.Create with new TObject() from Free with
>Delete. Remember all VCL objects must be created
>explicitely in CBuiler.
>I think the problem you are having is that your type
>TpScanInfo is not pointer type, but an "alias" for the
>structure. The convention I use is that a structure
>type has the format TStructure, and the typedef for a
>pointer to the structure is TpStructure. I know there
>are various ways to identify the name of a struct in C
>(whether you use straight C or C++ extensions), but I
>don't recall the exact differences.
>The cast you have is trying to cast from an integer
>(CallBackData) to a user defined structure, to the
>compiler complains. This will probably work,
>pScanInfo = TpScanInfo*(CallBackData);
>The idea is that a pointer is 4 bytes just like an
>Note that a proper value (ie, the address of a
>TScanInfo structure) must be passed to
>TScanner->Acquire(), to use this call back data
>You can avoid the call back data mechanism, by simply
>holding the information globally on the form.
>Best regards,
>>I am testing your Library with C++ Builder 5 Pro. I am
>>trying to create a C++ Builder App to test with based
>>on your Delphi/Pas Demo. Do you have the same code in
>>Here is a sample of my code and the current error I am
>>In Header file:
>>private: // User declarations
>> void __fastcall OnAcquire( const THandle
>>DibHandle, const unsigned short XDpi,
>> const unsigned
>>short YDpi, const int CallBackData);
>> typedef struct TpScanInfo
>> {
>> bool MultiPage;
>> const TTiffGraphic* Graphic;
>> TFileStream *ScanStream;
>> long int ImageCount;
>> } TScanInfo;
>>In CPP Unit:
>>void __fastcall TForm1::OnAcquire( const THandle
>>DibHandle, const unsigned short XDpi,
>> const unsigned short YDpi,
>>const int CallBackData)
>>TScanInfo *pScanInfo = new TScanInfo;
>>pScanInfo = TpScanInfo(CallBackData);
>>Here is where the error is generated:
>>[C++ Error] MainUnit.cpp(77): E2031 Cannot cast from
>>'const int' to 'TForm1::TpScanInfo'

[ Next Thread | Previous Thread | Next Message | Previous Message ]


[ Contact Forum Admin ]

Forum timezone: GMT-5
VF Version: 3.00b, ConfDB:
Before posting please read our privacy policy.
VoyForums(tm) is a Free Service from Voyager Info-Systems.
Copyright © 1998-2019 Voyager Info-Systems. All Rights Reserved.