Пример 2 (ListBox)

Private Sub ListBox1_Change()

Select Case ListBox1.ListIndex

Case 0

Me.BackColor = vbYellow

Case 1

Me.BackColor = vbGreen

Case 2

Me.BackColor = vbRed

End Select

End Sub

Private Sub UserForm_Initialize()

ListBox1.AddItem "Желтый"

ListBox1.AddItem "Зеленый"

ListBox1.AddItem "Красный"

'ListBox1.ListIndex = 0

End Sub

В завершение разберем следующий пример:

Дана функция F(x)=2x-sin(x)-0,5.

Ø Найти корень уравнения на интервале [-1,1],

Ø вычислить значение на интервале [-1,1] с шагом =0,1 и

Ø построить график функции

Текст программного кода приведен ниже

Function f(x As Double) As Double

f = 2 * x - Sin(2 * x) - 0.25

End Function

Private Sub CommandButton1_Click()

Dim a As Double

Dim b As Double

Dim c As Double

Dim h As Double

Dim x As Double

Dim y As Double

a = CDbl(TextBox1.Text)

b = CDbl(TextBox2.Text)

h = CDbl(TextBox4.Text)

eps = 0.0001

If OptionButton1.Value = True Then

Do While Abs(b - a) > eps

c = (a + b) / 2

If f(a) * f(c) > 0 Then

a = c

Else

b = c

End If

Loop

c = (a + b) / 2

Label3.Caption = "Результат" & Chr(13) & _

"Значение корня = " & c

'TextBox3.Text = c

Label3.Visible = True

End If

If OptionButton2.Value = True Then

x = a: i = 0

Do While x <= b

y = f(x)

ListBox1.ColumnCount = 2

ListBox1.ColumnWidths = "30;40"

ListBox1.AddItem x

ListBox1.List(i, 1) = y

i = i + 1

x = x + h

Loop

ListBox1.Visible = True

Label4.Visible = True

End If

If OptionButton3.Value = True Then

x = a: i = 1

Do While x <= b

y = f(x)

Worksheets(2).Cells(i, 1) = x

Worksheets(2).Cells(i, 2) = y

i = i + 1

x = x + h

Loop

График

End If

End Sub

Private Sub CommandButton2_Click()

Hide

End Sub

Private Sub UserForm_Initialize()

TextBox1.Text = " "

TextBox2.Text = ""

TextBox4.Text = ""

TextBox1.SetFocus

End Sub

Sub График()

'

' График Макрос

' Макрос записан 28.05.2009 (Татьяна Донец)

'

'

i = 1

While Worksheets(2).Cells(i, 1) <> ""

i = i + 1

Wend

i = i - 2

Range("A1:B" & i).Select

Charts.Add

ActiveChart.ChartType = xlXYScatterSmoothNoMarkers

ActiveChart.SetSourceData Source:=Sheets("Лист2").Range("A1:B" & i), PlotBy:= _

xlColumns

ActiveChart.Location Where:=xlLocationAsObject, Name:="Лист2"

With ActiveChart

.HasTitle = True

.ChartTitle.Characters.Text = "График функции"

.Axes(xlCategory, xlPrimary).HasTitle = False

.Axes(xlValue, xlPrimary).HasTitle = False

End With

End Sub