Лекция: Площадь фигуры

Абстрактный класс

MustInherit Class Figure

Public MustOverride Function Ploshad() As Single

End Class

Класс четырехугольник

Class Quadrangle

Inherits Figure

'Сторона четырехугольника

Private a, h As Single

'Конструктор

Public Sub New(ByVal a1 As Single, ByVal h1 As Single)

a = a1

h = h1

End Sub

'Реализуем метод Ploshad

Public Overrides Function Ploshad() As Single

Return a * h

End Function

End Class

Класс круг

Class Circle

Inherits Figure

'Радиус

Private r As Single

'Конструктор

Public Sub New(ByVal r1 As Single)

r = r1

End Sub

'Реализуем метод Ploshad

Public Overrides Function Ploshad() As Single

Return Math.PI * r * r

End Function

End Class

Основная программа

Public Class frmSFigure

Private Sub btnExit_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnExit.Click

End

End Sub

Private Sub rdbQuadrangle_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles rdbQuadrangle.CheckedChanged

Dim SQuad As New Quadrangle(Convert.ToSingle(txtA.Text), Convert.ToSingle(txtH.Text))

lblS.Text = «S=» & Convert.ToString(SQuad.Ploshad)

End Sub

Private Sub rdbCircle_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles rdbCircle.CheckedChanged

Dim SCircle As New Circle(Convert.ToSingle(txtR.Text))

lblS.Text = «S=» & Convert.ToString(SCircle.Ploshad)

End Sub

End Class