delphi

delphi JvPasswordForm1

hello experts I had an old JVC components with JvPasswordForm1. It seems this component does not exist any more: what component is it replaced by ? reagrds ...

NaN giving an error depending on Python startup?

Hi, I am using Python4Delphi to embed Python in a Delphi program. Versions: Python 2.6.4, Delphi 2009, Windows XP. The Delphi program crashes with EInvalidOp when importing json. I tracked it to the line NaN, PosInf, NegInf = float('nan'), float('inf'), float('-inf') in json.decoder. Sure enough, the command float('nan') raises an ...

OpenOffice Automation Delphi how use a callfunction

Hello, please help me with the following: I want to determine the maximum value in an open office calc column using the OOoTools.pas interface. This as fas as I come: Procedure FindMaximum(oMySheet : Variant); Var oFuncService : Variant; Begin oFuncService := CreateUnoService('com.sun.star.sheet.FunctionAccess'); ShowMes...

How to convert a integer to float in Delphi?

Hi, How to convert a integer to float in Delphi? E.g int_h:= int_var/1.5* int_var; ...

insert to a diffrent table onNewRecord

got an ADOQuery that has OnNewRecord event. on the procedure i try to add data automaticaly to another table. the data is a few rows that are needed and handled in clientDataSet in case of cancellation. at the loc OtherAdoQuery.insert; i get error that ADOQuery failed to insert null into a non null field. i am in insert mode, howev...

Delphi - External exception C0000008 when application is run from within the IDE

When an application is run from within the IDE and the debugger is attached the exception 'External exception C0000008' is raised when it tries to connect to an imported ActiveX control. If the application is ran standalone or the Rad Studio options/ Debugger Options/ Integrated debugging is unchecked, the program works as expected, no ...

Store a Password Securely.

I need to "password protect" my application but need advice on where to store the password securely. How I intend to do this: The first time the program is run, I will prompt the user to create a password. The password will be salted and hashed in SHA-256 then stored in either the Registry or a file. The Problem: If I store the hashe...

Getting equavalent of strings like chr(33)+'test line'+chr(33)

Above string equals "3test line3" When I enter above line into an editbox, and say; StrVar := Edit1.text; StrVar is "chr(33)+'test line'+chr(33)" How can i get the result 3test line3 as a variant; To achieve this, i use pascal scripting engine from rem-objects. Might be a simpler way to do this.. Any ideas are welcomed... ...

Connecting Windows desktop applications to a remote location.

I would like to know how I can connect remote offices to a central database. Here is the scenario: Office with several users working on a windows desktop application This application get it’s data from the database in the office server. Now 1 or more remote (offices, stores, whatever) need to have access to the same data. How can we...

I can't get Delphi Context-sensitive help working in open and save dialogs

I have a Delphi 2006 app with a CHM help file. It all works OK except that I cannot get any help to connect to the "Help" button on the TOpenDialog and TSaveDialog. A simple program demonstrating this is shown below. Clicking button 2 opens the help file and displays the correct page. Clicking button 1 opens the dialog, but clicking ...

error in Delphi loadlibrary()

i have given a chance to my software user to select dll from openfile dialog.(so my user can download dlls form my website and use it with the main project ). everything is working fine and it can even find that dlls is provided by me or selected an invalid dll.but the problem raises if the user selects a renamed file(eg : apple.txt file...

Check if a directory is readable

How we can check if a directory is readOnly or Not? ...

Canon EOS 1000 / Nikon + Delphi

hi! I am looking for a way to be able to control my Canon or Nikon camera from delphi, Basically I need to find a way to receive the new image while the camera is connected with USB on the fly, i.e. detect when a new picture was taken, so I can take action in my application for example cropping the image, adjusting brightness etc etc I...

40 million page faults. How to fix this?

I have an application that loads 170 files (let’s say they are text files) from disk in individual objects and kept in memory all the time. The memory is allocated once when I load those files from disk. So, there is no memory fragmentation involved. I also use FastMM to make sure my applications never leaks memory. The application comp...

Bresenham's line drawing in Delphi - problems with Sign(x) function

I've been tasked to draw eight lines, forming something like a regular eight-point star, with Bresenham's line drawing algorithm. It was to be done in Delphi language. As I'm not really good at canvas drawing, I simply copy-pasted the algorithm from Wikipedia for Object Pascal, with minimum changes. But the Wikipedian algorithm had the ...

Component Streaming and automatic source file updating

I'll start by saying my previous experience with component design was limited to fixing minor bugs in a pretty standard collection of visual controls. I am currently working on a project which uses a tree of TPersistent descendants to define, store and retrieve data. The top of this tree is a descendant of TComponent. It has a publishe...

Loading large image in parts in Timage component

I have a large images on server. When user request for any one I download them on to the client machine and once it is complete I load it into Timage control. Now what client is requesting that the image must come in chunks(parts) and as soon as a chunk is downloaded it must be shown in Timage control and as soon as other chunk download...

How reliable is the Random function in Delphi

I am writing a program which write statistical tests in Delphi (must be Delphi) and I've heard that the Random functionality is somewhat odd. You have to call randomize to randomize the seed of the random function when the program starts. I'm wondering if the random function (after calling randomize) is random enough for statistical t...

How can I automatically give an .exe a unique name at compile time?

I want the exe name of an application given 'ProgramExeName + version number' at compilation time (exemple: Filename18190.exe, Filename18191.exe...) - so the exe name is never the same. Considering i have the version number put in a str variable, how to automatically append this number to the exe name currently built? Tx (Note: i want...

Delphi TAdoQuery - Multiple Inserts?

Is it possible with a Delphi TAdoQuery to execute multiple inserts in one go, or do you have to execute each statement separately? What I want to do is this: AdoQuery.SQL.Clear; AdoQuery.SQL.Add('INSERT INTO user VALUES (1, "User 1");'); AdoQuery.SQL.Add('INSERT INTO user VALUES (2, "User 2");'); AdoQuery.SQL.Add('INSERT INTO user VALUE...