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Common Delphi Question and Answers

Questions and Answers

Install Issues
Multitier/Remote Datasets
Object Pascal Issues
Quick Reports
Windows API

Questions and Answers


'DAX Error: Access is denied' error
'DAX Error: Server execution failed' error
'DAX Error: Unexpected failure.' error
'EOleSys..operation unavailable' error
'Error 0: RLINK32 error opening file (TypeLibrary).tlb' error
'Error saving I(Interface)'
'TActiveFormX declaration missing or incorrect' error
Access violations with VC++ created OCX controls
ActiveForms not displaying in Internet Explorer
Automating Word 7
Client launching
Missing ProviderName in TClientDataSet
New methods not showing in code insight window
Old ActiveForm information displayed
Propigating constraints from middle-tier to client
What directory is the ActiveForm in


'Duplicate resource' error
Big-endian and little-endian formated integers
Cannot write EXE or DLL to disk.
Conditional defines for all Delphi versions
Data segment too large error.
Resizing an array


About Deploying DBClient in a Web Application
Accessing Server Methods from Client
Application Server Forms
Benefits of the ConstraintBroker
Checking for NULL in OnUpdateData handler
Comparison of Sockets, DCOM, OLE Enterprise
Connection Checklist
Database login for multiple clients
Dataset event handlers
Dataset event handlers not fired
Deploying Midas
Displaying a list of constraint error messages
Error: "DAX Error - Name not unique in this context"
Error: 'Interface not supported'
Error: "Application is not licensed to run this feature"
Error: "Cannot load IDAPI service library"
Error: "Could not find IDataBroker in type library"
Error: "DAX Error class not registered."
Error: "EOleSysError : Error loading type library/DLL"
Error: 'DAX Error - Name not unique in this context'
Error: 'DAX Error class not registered.'
Error: 'EOleSysError : Error loading type library/DLL'
Error: 'General SQL Error : Connection does not exist' in threaded application
Error: 'Interface not supported'
Error: 'Missing Data Provider or Data Packet'
Error: 'Name Conflicting'
Error: 'RPC Server is unavailable'
Error: 'Trying to append data to a non-partial dataset'
Error: 'Windows Socket Error: (10060), on API 'connect''
Error: 'Windows Socket Error: (10060), on API 'connectĘ'
Files necessary to run Application Server
How to use the TUpdateSQLProvider.OnUpdateRecord method
Locating the servers available in the registry
Logging in to the remote datamodule
MasterSource/MasterFields behavior
Minimizing Connections
Modifying application server SQL from the client.
Moving the application server to another machine
Multiple Transports
ODBC Constraints
Providing lookup capability
Re-executing export From Table
Resource Usage
Sending a file via DCOM
Server Termination
ServerName property (TMidasConnection or TRemoteServer)
Single Tier Applications
Single and multiple application server instances
Sorting on Calculated fields
TCP/IP: DCOM Dependency?
TCP/IP: Load balancing, OLE Enterprise
TCP/IP: Retrieving Client IP and Host Name
TCP/IP: TMidasConnection, Socket Server
TClientDataSet, auto-increment fields
TClientDataSet.Data property
TProvider Component vs. Provider Property
Table data subset through IProvider
Testing IDispatch Descendants
Un-registering a server
Using Multiple Servers
Using Stored Procedures
Where to get TUpdateSQLProvider component


'Object not found' with STANDARD database
'Your application is not enabled for use with this driver' error
Copying a information from one memo field to another using TBlobStream Creating a Lookup field at runtime
Debugging into the VCL source code
Displaying the selected row of a DBGrid in a different color
Getting values in a TDBGrid before they are posted
How can I place a string that is padded with spaces into a
Making sure changes survive a power failure Making the drop-down list appear faster MaxLength property of a DBEdit is not automatically set
Native Access driver and ISAPI/NSAPI
Retrieving BDE system information
Sharing data dictionaries
Specify a DefaultExpression for a TField object
Storing/Playing an .AVI file in a database
open or create a project using the TReport component
using the Lookup method to return values from multiple columns


"Error reading symbol file." error
'Tried to search marked block but is invalid' error
Auto increment Build Number
Changing delphi default directory Changing the default form size
Changing the default project directory
Changing the default width/height of the editor
Changing the location of the object repository
Compile Error: Too many files open
Compiler options.
Delphi starup failure.
Determining if you have Delphi v3.02 installed
Error Setting Exception Debug Hook
Error warnings too long
Going to the next compiler error
How can I disable the Delphi / Borland C++ Builder splash screen
How can I retrieve a list of assigned properties
IDE highlighting the incorrect line
Illegal Operation, Windows Lockup, IDE
Indenting a block of code
Inserting a file at the cursor
Is there any way to record a keyboard macro in the IDE?
KeyStrokes: Opening files in Delphi editor.
Object Inspector and Enter Key
Placing multiple copies of a component on a form. Preventing system lockup in Win95.
Recompiling complib.


'Invalid configuration parameter for alias
'Invalid filename' error
Native Access driver and ISAPI/NSAPI
Returning an image from a Web Server Application

Install Issues

'$2109 Cannot initalize the BDE' error when deploying InstallShield application
Availability of Delphi/400 Client Server Suite
Benefits to AS/400 developers and users
Component Palette Corruption Problems
Determining the version/release of Delphi 3
Doing a complete reinstallation of Delphi 3
Evaluation Copies of Delphi/400 Client Server Suite
How does Delphi/400 complement and add to Borland's strategy?
Local InterBase: 'Internal Error; Near: query shellmgr' error
Local Interbase Startup Configuration.
Minimum Hardware and Software Requirements
Minimum Hardware and Software Requirements for Delphi/400
More Info on Delphi/400 Client Server Suite
Purchasing Delphi/400 Client Server Suite
Raize components: 'Can't Load Package' error
Run-time Error 255
Technical Support for Delphi/400
Upgrade to Delphi/400 for Delphi Developer users
What is Delphi/400 Client Server Suite?
Why isn't a network install of Delphi 3 supported?


Converting a TColor value to a HTML Color string
Disabling autodial when using internet controls.
Displaying documents in the default browser
Getting the local internet machine name and IP address.
InterBase access from a web server application
Launching a web browser
Loading a local html file in the HTML control
Loading a locale file into the THTML component
Multi-Threaded ISAPI DLLs
Newsrc file format
Printing a WEB page with the HTML control?
Printing a web page using the HTML control
TClientSocket and TServerSocket
Testing if you are connected to the internet
Windows Dialer dials out when I am already connected to the internet


Adding hint windows to applications
Adjusting form size to accommodate a required client size
Changing com port config via Win95 CommConfig Dialog
Clearing the window in a console application
Component palette shown incorrectly
Control Panel Applets
Converting a number from one base to another
Converting in between RGB and CMYK
Converting strings to dates Creating a Resource only DLL
DBGrid fixed leftmost column
Declaring a SafeArray in the type library editor
Deleting an executable while it is running
Detecting if there's a disk in a drive Duplicate resource errors
How can I capture an image from a video source?
How can I convert a .dfm file to text and vise versa.
How can I determine the week number of a given day in the year?
How do I launch the Control Panel (and its applets)
Images conflicts between different versions of IE
Installing old Delphi 2 components
Intel's Lan Desk management Suite causes lockup
Migrating a project from Delphi 1 or 2 to Delphi 3
Notifying applications that the registry has changed
Opening an application's help file
Painting a rainbow color spectrum onto a form
Parameter value not in allowed range
Play an AVI file that has sound, silently
Querying the Audio Cd Autorun feature of Win32
Rebuilding components
Sending an image to the printer
Setting a transaprent background color for TImageList
Setting comm port configuration programmatically under Win95
Show a AVI clip in full screen zoom mode
Specify an overlay image for a node in a treeview
TTollBar and TSpeedButton misaligned
Testing/setting the CD autorun option under Win32
Text in Windows metafiles
Turning the screen saver off?
Using Visual Basic arrays in Delphi
Using an AVI file with TAnimate
getting DLL function parameter listings

Multitier/Remote Datasets

'Cannot load IDAPI service library' error during connect
'Could not find interface IDataBroker in type library' error
'Provider name was not recognized by the server' error
Accessing new interfaces in a RemoteDataModule
Client application hang
Error reading Database1.SessionName
Error reading Session1.SessionName
Error: 'Mismatch in datapacket'
Invalid class string' error during connect
Remote datasets for multiple clients
Using TClientDataSet with local data

Object Pascal Issues

Assigning a comp type to an integer
Bitwise AND evaluates different under Delphi 3
Calculating a point using angles and distance Calculating an angle from two points Calling DeleteFile function Converting 16bit resource to 32bit. Converting a number from one base to another Converting an RGB color to a CMYK color. Covert string of (zeros and ones) to binary. Creating resource files.
Delphi .dcu format Detecting display changes. Disabling ALT-F4 to prevent form closing
Embedding a copyright symbol in a string? Embedding a quite in a string.
Explaination of rounding
Finding distance between two points. Flush binary file from disk cache to disk
Formatting and displaying integers with commas
Getting a handle on your files
Getting the Lowest common denominator. Handling command line params with spaces How can I assign a file variable in a Record?
How can I avoid an access violation when using the move procedure
How can I create a dynamic array of TPoints to draw a polygon?
How can I easily move a Window control at runtime?
How can I prevent the user from moving or sizing my form?
How can I test if a given string contains a valid number?
How do I create a Resource only DLL?
How do I create a power function?
How do I recurse sub directories?
Integer to 'Binary String' Linking and animated cursor to a resource file. Passing a function to a procedure or vice versa.
Porting strings from 16 to 32-bit
Read and BlockRead file function failure in 32bit. Reassigning events at runtime
Record alignment in 32bit pascal. Returning application's exit code.
Setting the MaxPage property of the PrintDialog component
Stack Overflow, Runtime error 202;
Storing icons in your application for use at runtime?
StrPCopy and long strings String Trim functions.
The TDateTime component commonly ignores key input
Using far pointers. Using global values in your application.
Working with Floating Point, Double, Single, Real, Extended types
Working with objects and functions in other units
calling windows Beep() function passing functions/procedure to other functions/procedures

Quick Reports

A sum(if(...,...,0)) always returns 0 Adding sums of fields Blank form at design or run time
Font problems on NT 4.0 Getting AddPrintable to work Getting the summary function to work Improving performance Is there a TQRDBMemo? No default printer selected Printing Delphi controls Printing a footer on only the last page Printing calculated text Printing to another printer than the default one Saving a QuickReport custom preview to text
Setting the caption of the preview window Stretching memos Switching between different data sources TQRExpr does not recognize DisplyFormat settings
The Count function Using a TQRExpr component at run-time Using additional data sets in expressions


Accessing HKEY_LOCAL_MACHINE under NT without Admin. rights
Accessing a grid's column/row by name
Adding accelerator characters to TTabsheets
Adjusting number and with of columns in a TFileListBox
Aligning maximized forms
Arrow and Function Keys
Avoiding an Application Error when using EM_POSFROMCHAR
Avoiding flicker on DrawCell
Bitmaps and captions on TBitBtn
Calls to the abort method fail to compile
Can I use the AssignPrn method to write directly to a port?
Changing RichEdit Font styles with HotKey combinations
Changing font color on standard win controls.
Changing the font in a hint window
Changing the input caret
Changing the main form of an app. at runtime
Changing the owner of a component at runtime
Changing the printer setup between pages
Changing the root key
Clearing the contents of a Canvas
Click a speed button in code
Color problems in 256 color mode.
Colored text on a TStatusBar
Converting a color to its VCL string value
Create hints for Menu items
Creating Non-Visual Components Without Icons Creating a PolyPolygon using a point array. Creating new constructors Creating temporary canvas
Custom InPlace Editor in StringGrid Customizing TTrackBar
Deleting a directory and all the directories files
Detecting print errors
Detecting tab key press
Determining if a combobox is in dropped state. Determining if an object supports a property. Dialogs displaying 'No to all' button instead of mbHelp
Differences between Create(Self) and Create(Application)
Disabling a radio button in a TRadioGroup
Disabling system menu in code
Displaying a 24 bit True Color bitmap image on a 256 color display
Displaying the first frame of an AVI File
Does Delphi have an equivalent to the Visual Basic SendKeys function?
Does my CD-ROM Drive contain an Audio CD?
Draw on frame
Dynamically drawing a transparent image
Endless looping with the TMediaPlayer
Error 'There are no fonts installed'. Extracting RGB components of a color.
Forcing edit mode in a TListView via a keypress
Frame count of an AVI
Freeing an object stored in a list. Get a count and list all the controls on a TNoteBook
Getting a string representation of a Windows error code
Getting property information
Getting stronger type checking
Getting the actual size of a TComboBox
Getting the current line number of a TMemo?
Getting the path to the directory where Windows was installed from
Hiding your application from the Windows Taskbar.
How can I abort a lengthy operation?
How can I activate different hints for each cell in a grid
How can I change the drive that MediaPlayer uses to play Audio
How can I create a transparent form?
How can I detect if a non-menu key has been pressed?
How can I determining if a given machine has a math coprocessor.
How can I eject a CD-ROM in code?
How can I get the serial number of an Audio CD?
How can I have a TBitBtn component that has a word wrapped caption?
How can I place a bitmap in a Metafile?
How can I tell if the mouse is over my form?
How can I tell in code if my application is running on Windows NT
How can I use a true DWORD value passed to my Delphi application?
How do I Print a TStringGrid / TDBGrid?
How do I create a bitmap from an icon?
How do I make changes to the VCL code?
How do I plot a line? Implementing the VB TwipsPerPixel in Delphi Intercepting the Ctrl-V key in a TMemo
Justifying edit text.
Keeping a glyph's transparent area transparent.
Keeping an application minimized
Keyboard shortcut to a component that has no caption
Limiting the amount of text entered in a TEdit
Listbox selected property Memo Input and line breaks.
Metafile fonts and the VCL Moving a control at runtime with the mouse. Moving a form by clicking in its client area
Moving controls at runtime
Notifying forms of global changes
Overcomming Stream read error.
Overwrite in TMemo and TEdit
Performing undo on an edit control.
Placing a grid in edit mode programatically. Playing MPEG files in Delphi apps
Positioning the caret in an edit control.
Prevent the TEdit component from beeping when invalid
Preventing Components from Resizing Programmatically dropping down a menu
Radiogroups and focus
Raster operations. Reducing flicker on component redraw
Reducing the resource requirements of TNotebook and TTabbedNotebook
Refreshing the TDriveComboBox drive list
Registering a file extension and context menu operations Removing drives listed in a TDriveComboBox
Resizing StringGrid Columns
Retrieving the line number that a memo's cursor is on.
Save and load metafiles in a BLOB field without using DBImage
Saving a TFont Object.
Selecting a cell in a DBGrid
Selection rectangle
Sending a message to all controls on a form
Sending keystroke #255 to a windows control. Seting the number of fixed columns in a TDbGrid
Setting custom tabstops in a ListBox.
Shift, Ctrl, Alt key checking
Showing dbgrid is disabled
Showing two forms allowing the first to retain focus
Simulating a mouse move in code. Small bitmaps in a TPopUpMenu
Stopping TScrollbar button from blinking
StretchDraw on an icon
Subclass the window procedure for a TForm
TCombobox drop down size. TTimer not firing at correct interval
Transparent property to work for a CoolBar background bitmap
Trap scrolling messages for the ScrollBars of a TScrollBox
Trapping messages in non client area of a form. Trapping non client areas
Using Amperands inside Delphi
Using JPEGs from resource files
Using Resident Font
Using an Icon as the Glyph in a TSpeedButton
Using an animated cursor.
Using an instance of TPrinter
Using escape codes with the format() function
Using the Application's OnIdle Event.
Virtual key constants.
What is the tag property useful for?
Where is SYNCOBJS.pas unit?
Why Delphi drawing functions draw one pixel short.
adjusting the tab location in a TMemo component
displaying seconds, minutes, tracks of an AVI
doing work while application is Idle
drawing transparent text onto a TBitmap
inserting contents of a file at current position in TMemo
making a Delphi DLL with as little in the uses clause as possible
printing a TStringGrid or a TDBGrid
printing in color
responding when the user minimizes or maximizes a Form
saving TFont information

Windows API

Adding TrueType fonts to windows in code.
Adding a document to the Windows 95 Start Button's documents
Adding install to Win95 Add/Remove programs. Alloting CPU time
Broadcasting a message.
Calling windows RegisterClass function. Can I get function params from a dll.
Changing the background color of Text
Changing the display mode settings in code.
Changing the papersize of a print job.
Changing the port of a printer
Changing the printer port in code. Changing the printer setup between printed pages? Changing windows default printer in code.
Chaning Windows Default Printer
Chaning the Windows wallpaper in code?
Checking available disk space on large drives.
Checking drive ready status.
Checking if TrueType fonts are available.
Clearing the recent Documents from the Start Menu
Closing popup menu in system tray application
Color reduction techniques for graphics.
Controlling shortcut keystrokes in a string grid
Converting from Long to Short file names and paths
Converting resources from 16bit to 32bit.
Copying contents of a control to the clipboard.
Copying files using the Standard Windows Copy file dialog box
Creating a Win95 Shell icon application. Creating a bitmap form a pixel array
Creating a custom word break procedure
Creating a delay without a timer.
Creating a file association for my application? Creating a flashing icon
Creating a non-VCL console project.
Creating a palette with more than one entry
Creating a rotated font.
Detecting PlugNPlay hardware changes? Detecting how many jobs are in the print spooler
Detecting if the PrintScreen key has been pressed
Detecting if the system time has been changed
Detecting the full path/filename of a DLL
Detecting what direction a printer will rotate for a portrait
Determine the last access time of a given file
Determining Drive Type
Determining if Delphi Running.
Determining if a given printer is capable of printing a PostScript file
Determining is a canvas is a Metafile Canvas? Determining minor version number
Disabling Full Window Drag
Disabling close button of a window
Disabling the Win95 start button
Displaying a bitmap on the client area of an MDI parent form.
Displaying a file's associated icon.
Does Delphi have an equivalent for the VB function DoEvents?
Drag and Drop with Files
Drawing in scale without using Windows Mapping Modes?
Dropping a combobox's list in code.
Embedding a page break in the Rich Edit control
Executing a '.LNK' file
Executing a program from my application
Executing and application by extention. Executing the explorer find file dialog
External function failure when passing boolean parms.
Extracting Icons
Extracting an icon from a .exe or .dll.
Fast way to clear a given canvas
Formatting a drive under Win32
Generating a Windows Console Application
Getting a list of the available drives on a system
Getting a list of valid time zones from windows. Getting a printers capabilities. Getting an handle to a window in another application.
Getting bin names from your printer
Getting modem status under Win32
Getting printer capabilities
Getting the Printer driver and port name from TPrinter's
Getting the Win95 Desktop ListView Handle
Getting the Windows version in code?
Getting the filename and path of a local table.
Getting the handle of a Window containing a DOS box
Getting the longfilename from a file.
Getting the printing margin of the page
Getting the serial number of a disk.
Getting the size of the desktop.
Getting the taskbar handle.
Getting the time and date in Universal Time
Getting the windows directory.
Getting user name and company info from Windows.
Handing bitmap display.
Hiding the windows taskbar.
How can I beep the PC Speaker?
How can I close the CD Tray in code? How can I detect if a given key was pressed during application during startup?
How can I determine the names of the installed comm ports?
How can I dial out through the modem under Win32?
How can I draw directly on the Windows Desktop? How can I get serial number of my drive
How can I get the default Windows folders
How can I simulate a button click in code?
How do I convert a color to a shade of gray?
How do I create an icon from an bitmap?
How do I draw using LoEnglish Mapping Modes?
How do I launch a control panel applet? How do I move a file or directory?
How do I print in color?
How do I restart Windows in code.
How do I rotate a Metafile?
How do I tell if a sound card is installed?
How do I use Paths and Geometric Pens?
How many colors will my display mode support
Is my machine connected to the network.
Keeping an application in a minimized state?
Launching your default browser on a URL. Making ini file changes permanent. Making text background transparent
Maping a DLL into another process
No default printer selected error message.
Non VCL Bitmap buffering
Opening an explorer window to a given folder
Passing TPrinter handle to GetDeviceCaps() Prevent window update
Preventing multiple application instances
Preventing windows task switching
Printing in Delphi without using the TPrinter Unit
Printing to file.
Programatically installing printer driver
Programmatically closing another application
PtInRegion pixel function Reading dos environment variables Refreshing the windows desktop
Removing a forms caption bar?
Retrieving a long file name from the command line.
Retrieving a users login name.
Retrieving the program that is associated with a given extension
Running apps on Windows startup
Sending a file to the Windows Recycle Bin?
Setting a form's maxwidth in code.
Simultaneous printing to multiple printers
System Modal Windows on WinNT
Temporarily turning off range checking.
Timed beeps from the PC speaker
Trapping for when a user is done resizing a window
Trapping the Windows system key 'PrintScreen'
Trying to delete a running .exe?
Turning an low power compliant monitor off?
Turning on Screen saver with code.
Typecasting a PChar to a longint.
Using FindFirst to search for files.
Using GetTimeZoneInformation() function? Using InvalidateRect()to repaint the entire form
Using Tapi
Using mouse_event() to similate mouse events
Using the LzExpand functions in your applications
Using the Shell API function SHBrowseForFolder()
Using the WIN API high resolution performance counter
Using the WinApi GetObject to get a bitmap.
Writting a raw string of data to the printer.
Yielding cycles to other applications
adding system menu items to a form
displaying an application associated icons
re-mark a Delphi 16-Bit executable to be a Windows 4.0 application
rotating a Metafile

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