Essential Delphi 3 fast : Includes ActiveX Development

197 Pages·1998·11.1 MB·English

by  John Cowell BSc (Hons)

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John Cowell
Essential
Delphi 3 fast
Includes ActiveX Development
With 179 figures
, Springer
Author and Series Editor
John Cowell, BSc (Hons), MPhil, PhD
Department of Computer and Information Sciences
De Montfort University, Kents Hill Campus,
Hammerwood Gate, Kents Hill, Milton Keynes, MK7 6HP, UK
ISBN-13: 978-3-540-76150-1 e-ISBN-13: 978-1-4471-1518-2
001: 10.1007/978-1-4471-1518-2
British Library Cataloguing in Publication Data
Cowell, John, 1957-
Essential Delphi 3.0 fast : includes ActiveX control development
I.Delphi (Computer program language)
1.Title II.Delphi 3.0 fast
005.2'62
Library of Congress Cataloging-in-Publication Data
Cowell, John, 1957-
Essential Delphi 3.0 fast : jincludes ActiveX control development 1
John Cowell.
p. cm. -- (Essential series)
Incl udes index.
ISBN-13: 978-3-540-76150-1
1. Computer software--Development. 2. Delphi (Computer file)
1. Title. II. Series: Essential series (springer-Verlag)
QA76.76.D47C68 1997 97-40559
005.26'8--dc21 CIP
Apart from any fair dealing for the purposes of research or private study, or criticism or review,
as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be
reproduced, stored or transmitted, in any form or by any means, with the prior permission in
writing of the publishers, or in the case of repro graphic reproduction in accordance with the
terms oflicences issued by the Copyright Licensing Agency. Enquiries concerning reproduction
outside those terms should be sent to the publishers.
© Springer-Verlag London Limited 1998
Softcover reprint of the hardcover 1s t edition 1998
Microsoft, MS, Visual Basic, Windows and Windows 95 are trademarks of Microsoft Corporation
Ltd. Delphi is a trademark of Borland Ltd.
The use of registered names, trademarks etc. in this publication does not imply, even in the
absence of a specific statement, tlIat such names are exempt from the relevant laws and
regulations and therefore free for general use.
The publisher makes no representation, express or implied, with regard to the accuracy of the
information contained in this book and cannot accept any legal responsibility or liability for any
errors or omissions that may be made.
Typesetting: Camera ready by author
34/3830-543210 Printed on acid-free paper
Contents
1 WHY USE DELPHI 3? .................................................................................. 1
Introduction .............................................................................................. 1
What this book covers .............................................................................. 2
Getting started .......................................................................................... 2
What computer you need to run Delphi 3 ................................................. 3
What's new in Delphi 3 ............................................................................. 3
Converting from Delphi 2 to Delphi 3 ...................................................... 4
Conventions .............................................................................................. 4
2 THE DELPHI ENVIRONMENT ..................................................................... 5
Introduction .............................................................................................. 5
Running Delphi ........................................................................................ 5
The Delphi Environment .......................................................................... 7
The design form ........................................................................................ 8
The Component Palette ............................................................................ 9
The Object Inspector .............................................................................. 10
The unit window ..................................................................................... 11
The menu ................................................................................................ 11
The SpeedBar ......................................................................................... 12
Finding windows .................................................................................... 12
3 THE STANDARD COMPONENT PALETTE .............................................. 13
Introduction ............................................................................................ 13
Event Driven Software ........................................................................... 13
Changing component properties ............................................................. 14
The Label component ............................................................................. 16
The Edit component ............................................................................... 16
The Memo component ............................................................................ 17
The Button component ........................................................................... 18
The CheckBox component ..................................................................... 19
The RadioButton component .................................................................. 20
The ListBox component ......................................................................... 20
The ComboBox component. ................................................................... 21
The ScrollBar component ....................................................................... 22
The GroupBox and RadioGroup components ........................................ 23
The Panel component ............................................................................. 23
MainMenu and PopupMenu ................................................................... 24
Using the components ............................................................................ 24
vi Contents
4 USING THE STANDARD COMPONENTS ................................................ 25
Introduction .................................................................................... ". ...... 25
The Changeling application ................................................................... 25
Creating the user interface ...................................................................... 26
Adding the Memo and Panel components .............................................. 27
Adding the ListBox and ComboBox components .................................. 27
Adding the RadioButtons ....................................................................... 27
Completing the user interface ................................................................ 28
Changing the text colour ........................................................................ 29
Changing the background colour ........................................................... 31
Changing the text size ............................................................................ 31
Changing the font ................................................................................... 32
Italic ising the text and closing the application ....................................... 33
The completed code ............................................................................... 33
An easier technique ................................................................................ 35
5 THE ADDITIONAL COMPONENT PALETTE ............................................ 37
Introduction ............................................................................................ 37
The BitBtn component ........................................................................... 37
The SpeedButton component ................................................................. 38
The MaskEdit component ...................................................................... 39
The StringGrid component ..................................................................... 41
The DrawGrid component ...................................................................... 42
The Image component ............................................................................ 43
The Shape component ............................................................................ 43
The Bevel component ............................................................................ 44
The ScrollBox component. ..................................................................... 45
The CheckListBox component ............................................................... 46
The Splitter component .......................................................................... 46
The StaticText component ..................................................................... 47
The Chart component ............................................................................. 47
6 DISPLAYING AND READING TEXT ......................................................... 51
Introduction ............................................................................................ 51
The ShowMessage procedure ................................................................. 51
The MessageDlg function ...................................................................... 52
What button was pressed? ...................................................................... 53
Creating input forms .............................................................................. 54
Standard dialog boxes ............................................................................ 55
Displaying dates and times ..................................................................... 57
Displaying numbers ............................................................................... 59
Contents vii
7 USING FORMS .......................................................................................... 61
Introduction ............................................................................................ 61
Creating new forms ................................................................................ 61
Finding forms ......................................................................................... 63
Modal and modeless forms ..................................................................... 63
Displaying forms .................................................................................... 64
Unit files ................................................................................................. 65
The Dialogs page .................................................................................... 68
The OpenDialog component. .................................................................. 68
The SaveDialog component ................................................................... 70
The OpenPictureDialog component ....................................................... 70
The SavePictureDialog component ........................................................ 71
The FontDialog component .................................................................... 71
The ColorDialog component .................................................................. 72
The PrintDialog component ................................................................... 73
The PrinterSetupDialog component ....................................................... 74
The FindDialog component .................................................................... 74
The ReplaceDialog component .............................................................. 75
SDI and MDI forms ................................................................................ 75
Creating parent and child forms ............................................................. 76
Displaying child forms ........................................................................... 76
Closing child forms ................................................................................ 77
Arranging forms ..................................................................................... 78
The Object Repository ............................................................................ 78
8 OBJECT PASCAL ..................................................................................... 80
Introduction ............................................................................................ 80
Standard data types ................................................................................. 80
Declaring variables ................................................................................. 82
Declaring constants ................................................................................ 82
Converting between types ...................................................................... 82
Operators ................................................................................................ 85
Bitwise operators .................................................................................... 86
Controlling program flow ....................................................................... 87
If then else statements ............................................................................. 87
Case statements ....................................................................................... 89
Repeat statements ................................................................................... 90
While statements ..................................................................................... 92
For statements ......................................................................................... 92
Calling procedures and functions ........................................................... 93
Passing by value and address .................................................................. 94
Using functions ....................................................................................... 95
viii Contents
9 CREATING RECORDS, CLASSES AND OBJECTS ................................ 97
Introduction ............................................................................................ 97
Defming data types ................................................................................ 97
Enumerated types ................................................................................... 98
Sub-range types ...................................................................................... 99
Arrays ................................................................................................... 100
Records ................................................................................................. 101
Why bother with object orientation? .................................................... 102
Classes and Objects .............................................................................. 102
Using properties and methods .............................................................. 103
Creating classes .................................................................................... 104
10 CREATING ACTIVE FORMS ................................................................. 107
Introduction .......................................................................................... 107
Writing Web pages ............................................................................... 107
Using Java ............................................................................................ 108
ActiveX components ............................................................................ 109
ActiveX and Java ................................................................................. 109
The Active Form .................................................................................. 109
Starting the application ......................................................................... 110
What the application does .................................................................... 111
Creating the User Interface .................................................................. 111
The Object Pascal code ........................................................................ 112
Web Deployment ................................................................................. 116
The Web page created .......................................................................... 117
Running the application ....................................................................... 118
11 MOUSE AND KEYBOARD EVENTS ..................................................... 120
Introduction .......................................................................................... 120
The mouse events ................................................................................. 120
Tracking mouse movement .................................................................. 121
OnMouseDown and OnMouseUp events ............................................. 122
Dragging and dropping ........................................................................ 122
Dragging to the right position .............................................................. 123
The keyboard events ............................................................................ 125
Using the OnKeyDown event .............................................................. 126
The KeyPreview property .................................................................... 127
12 CREATING AND USING GRAPHICS .................................................... 128
Introduction .......................................................................................... 128
The graphics controls ........................................................................... 128
Creating Images ................................................................................... 129
Contents ix
The Tools Palette .................................................................................. 129
Editing images ...................................................................................... 131
Testing bitmaps, icons and cursors ....................................................... 132
Images, cursors and icons ..................................................................... 133
Using Text ............................................................................................ 133
Using Colour ........................................................................................ 134
Adding graphics at run-time ................................................................. 135
The Pen property .................................................................................. 135
Drawing lines ........................................................................................ 136
Drawing shapes .................................................................................... 137
The Brush property ............................................................................... 138
The Style property ................................................................................ 139
The Pixels property ............................................................................... 140
The ColorDialog ................................................................................... 140
Using the clipboard. .............................................................................. 141
13 MENUS ................................................................................................... 142
Introduction .......................................................................................... 142
Main menus and popup menus ............................................................. 142
Adding, inserting and deleting menu items .......................................... 143
Separator bars, accelerator and shortcut keys ....................................... 143
Creating sub-menus .............................................................................. 144
Designing popup menus ....................................................................... 145
Menu events ......................................................................................... 145
Changing the font and colour ............................................................... 148
The Menu Designer speed-menu .......................................................... 149
Menu templates .................................................................................... 150
Creating menu templates ...................................................................... 151
14 USING DATABASES ............................................................................. 152
Introduction .......................................................................................... 152
Relational data ...................................................................................... 152
What databases can Delphi use ............................................................. 153
Creating database applications fast.. ..................................................... 153
The Data Forms Wizard ....................................................................... 154
The Database Desktop .......................................................................... 159
Creating a new table ............................................................................. 159
Desktop tools ........................................................................................ 161
Adding data to a new table ................................................................... 162
Reading the table .................................................................................. 162
Using data controls ............................................................................... 163
The Table component ........................................................................... 163
The DataSource component ................................................................. 164
x Contents
Data aware components ....................................................................... 164
15 FIXING BUGS ........................................................................................ 165
Introduction .......................................................................................... 165
Types of errors ..................................................................................... 165
Code Insight......................................................................................... 166
Run-time errors .................................................................................... 168
Logic errors .......................................................................................... 169
Stopping the application ....................................................................... 170
Using breakpoints ................................................................................. 171
Restarting after breakpoints ................................................................. 171
Viewing breakpoints ............................................................................ 171
Stepping ............................................................................................... 172
The Debug toolbar. ............................................................................... 172
Viewing data ........................................................................................ 173
Conditional breakpoints....................................................................... 174
Using watchpoints ................................................................................ 174
Pausing programs ................................................................................. 175
16 THE VISUAL COMPONENT LIBRARy ................................................. 176
Introduction.......................................................................................... 176
The Win32 page ................................................................................... 177
The System page .................................................................................. 178
The Internet page .................................................................................. 179
The Data Access page .......................................................................... 179
Data Controls page ............................................................................... 180
The Dialogs page .................................................................................. 181
The Win 3.1 page ................................................................................. 182
INDEX ......................................................................................................... 188