Fundamentals of Visual Basic / PDF

Table of Contents

Fundamental facts

Kinds of modules

Visual Basic files

Visual Basic vs. VBA

How to insert new stuff

Variables

String à numeric value

Numeric value à string

Declaring variables explicitly (optional)

WHERE should variables be declared?

Indicating variable type in the variable names (optional)

Using variables

Private vs. public variables

What is the different between public and global variables?

Learning about objects with the Object Browser

Leftover notes

Creating a desktop shortcut

Creating applications

Setting the starting place for a new form

Using variables and procedures in multiple forms and event procedures

Creating menus

Creating nonstandard menus

Common dialog objects

DriveListBox, DirListBox and FileListBox controls

I/O controls

Radio buttons

Input boxes

Message boxes

Combo boxes

Creating nonstandard dialog boxes

Loading and unloading forms during runtime

Setting the properties of windows

Modal, nonmodal

Minimizing, maximizing

Parent and child windows

Various notes on creating applications

Creating the user interface: windows

Declaring arrays

Creating an executable file

Using an OLE object to launch applications

Viewing an Access DB

Using the ADO Data Control and DataGrid Control

Second method

Loops and decision structures

Existing a loop

Programming technique

Image Box

Branching back from a GoTo destination

Enabling Drag and Drop

Something is to occur even in the absence of any event

Events occur for a certain time span

Running a DIFFERENT event procedure while some event is being processed

Calling another procedure from within an event procedure

Start an application without automatically showing a specific form

A control covers the entire area of a form

Width vs. ScaleWidth, Height vs. ScaleHeight

Interpreting and using keypresses

The event procedures of what objects can be used to trap keypresses?

Using the Form_KeyDown(), Form_KeyUp(), and Form_KeyPress() procedures

Using text

Make the text box cover the entire form area

Displaying text in a text box

Displaying text in a form

Displaying text in a picture box

Print/display formatting

Displaying table columns

Formatting text in a text box

Setting font size in a text box

Setting font name in a text box

Accessing a specific font

Using the Clipboard

Properties for manipulating text marked by the user

Clearing the clipboard

Sending text to the clipboard Ctrl + C

Sending text box text to the Clipboard

Sending combo box text to the Clipboard

Sending list box text to the Clipboard

Sending picture box images to the Clipboard

Cutting text Ctrl + X

Deleting text box text

Deleting combo box text

Deleting list box text

Deleting picture box images

Pasting text Ctrl + V

Pasting text to a text box

Pasting text to a combo box

Pasting text to a picture box

Pasting text to a list box

Determining what kind of stuff is currently in the clipboard

Printing

Printing a form

High-resolution printing

Printing a text string

Printing any text

Interesting Printer properties

Graphics

Easiest way to quickly move shapes around the screen

Programming artwork

Clear an image

When the programming calculates a new position for an object, when is the object repainted (moved)?

Refreshing the screen with the Refresh method

CurrentX, CurrentY

Specifying relative position

What is the difference between Width and ScaleWidth, Height and ScaleHeight?

Obtaining the color of a given pixel

FillStyle, FillColor

Horizontal and vertical scroll bars

Debugging

Program command equivalent to pressing the Break button

Frills, neat stuff

Allowing access to command buttons with the Tab key

Allowing access to command buttons with Alt + some key

Creating an application icon

Spelling dictionaries, detecting a document's language

Active spelling dictionaries

Custom dictionaries

A document's language

Reading text files, with the FileSystemObject

Important concepts

Basic procedure

Creating a text file

Opening a text file

Writing to a text file

Closing an open file

Reading from a text file

Writing and then reading, etc.

VBScript

Basics

Adding an ActiveX Control to a page in FrontPage

Viewing or modifying control properties

Programming techniques

Accessing objects

Accessing a single object in an array kind of way

Accessing a single object by its name

Accessing an entire collection of objects

Working with multiple forms

Setting the contents of the browser's status bar

Clicking on a button evokes a hyperlink

Appendix

Visual Basic Web sites

Reds

Scrawlings

Arbitrary text

ListFonts

Creating game screens with fonts and VB graphics

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Sample of the pdf document

How to insert new stuff

In Visual Basic, select the Tools menu.

There, select Macros.

Select a macro.

Click on the Edit button.

You will see the current macro code in the Code window.

Modify it as you want.

Click on Run Sub.

Variables

Data types: Halvorson, p. 130

Naming conventions: Halvorson, p. 261

It is not true that all VB variables default to the string type. However, note the following:

Any time your application receives user input from an input box, that input is always automatically a string. You must use Val if you want to have numeric values.

Also, label captions must be strings. Anything else results in a type mismatch error.

String values are assigned to variables like this:

LastName = "Jefferson"

not LastName = Jefferson

See Halvorson, p. 121, the code at item 6

Salary = 5000

Salary is a number and can be directly manipulated mathematically.

String à numeric value

Use the function Val

Example: Halvorson, p. 137 – 8, application \Vb6Sbs\Less05\BasicOp

Input à mathematical manipulation

Any time your application receives user input from a text box, that input is always automatically a string. You must use Val if you want to have numeric values.

Do not confuse Val with the Asc function. The latter converts an ASCII character into the corresponding integer.

Numeric value à string

Use the function Str

Mathematical manipulation à output

The obvious use: You have done a lot of mathematical manipulations. In order to display the result in a label, with the caption property, you must first convert the number result to a string.

Do not confuse Str with the Chr function. The latter converts an integer into the corresponding ASCII character.

Declaring variables explicitly (optional)

Use the Dim statement.

Dim Interest%

Dim Intest as Boolean …

The specification of variable type (such as %) is optional. If you specifiy no variable type (simply Dim Interest), the variant type is used by default.

The variable types are listed in Halvorson, p. 130.

You can force yourself to always make explicit variable type specifications. Halvorson describes how on p. 120.

WHERE should variables be declared?

Variables for all procedures (public variables) must be declared in a standard module (=General/Declarations). See Halvorson, Lesson 10.

Variables for only one procedure (local variables) are declared within that procedure.

Indicating variable type in the variable names (optional)

· Use the symbols on p. 130 in the table's Sample usage column. Example:

· Or add a prefix to the variable name, such as strName, if Name is a string variable.

Using variables

For a good example, refer to \Vb6Sbs\Less05\Data. This app is discussed in Halvorson, p. 132.

Private vs. public variables

Standard modules contain public variables, used in multiple procedures. Refer to Halvorson, Ch. 10.

Halvorson provides an example of private variables on p. 132.

What is the different between public and global variables?

Declaring the ggFlag variable means that this variable is visible by all procedures in all modules and forms:

Global ggFlag As Integer...........