VBA development technology. (Lecture 6) презентация

data;
GUI design;
code writing;
implementation with IDE;
application analysis;
testing;
performing of a program;
analysis of results.

names are:
UserForm1; TextBox1, TextBox2; Label1, Label2.
Prefix naming:

frmCheck; lblPrice; txtPrice; cmdCalculate

and understand
txtNewPrice, txtNew_Price
No spaces, dots and other special symbols instead underscore

own default property which may be used without dot notation, e.g.

txtCost.Text = txtPrice.Text*txtQuantity.Text

is the same as

txtCost = txtPrice * txtQuantity

in case if all controls are TextBoxes.

used to describe such variables

Constants are used for constant variables like PI (3.14) etc.

Const operator is used to describe such variables

possible values for this variable

Dim i As Integer … i = 0 … i = i + 1

Dim operator reserves memory field of specific type for corresponding data type.

CompanyName= “Microsoft” … L = 2 * PI * R …

Embedded into VBA constants start with vb prefix.
vbRed – red color
vbSunday – sunday
vbCrLf – new line
vbYesNo – Yes and No buttons

true or false.

is statement that is opposite to operand: 5 > 2 =True Not (5 > 2) = False

Logical AND is a statement when both its operands are true, e.g.
a < x < b is the same as (a < x) And (x < b)
Logical OR is a statement when at least one of its operands is true.
(i=5) Or (i = n)

19:40#

to date,
DateDiff("ww",#1.01.2001#,Date) – amount of weeks between date and begin of century.

AND (And);
3) Logical OR (Or).

Arithmetical:
1) powering (^);
2) negation (-);
3) multiplication and division (*, /);
4) integer division (\);
5) modular summation (Mod);
6) addition and subtraction;
7) string concatenation (&).

Comparison:
=, <>, <, <=, >, >=

then result is assigned to variable.

txtCost = txtPrice * txtQuantity

may use only variables those were described with Dim earlier.
Option Explicit operator allows VBA environment to look about this rule

причем выбор зависит от условия.

than single operator

Block model is used when at least one branch has more than one operator

max = a Else max = b

If txtPrice = "" Then MsgBox “Please input price", _ vbExclamation, “Attention"

Else
Operators2
End If

If Condition Then
Operators
End If

If Condition1 Then
Operators1
ElseIf Condition2
Operators2
…
[Else
OperatorsN]
End If