frmseating.vb

这是一个飞机订票的软件

    ' for each airplane type.
    Private Const cintCheckBoxHeight As Integer = 15
    Private Const cintCheckBoxWidth As Integer = 15

    Private Const cint757Seats As Integer = 6
    Private Const cint757Rows As Integer = 38

    Private Const cint777Seats As Integer = 8
    Private Const cint777Rows As Integer = 45

    ' The variables mintFull and mintEmpty store the number of
    ' occupied and empty seats on the airplane.
    Private mintFull As Integer
    Private mintEmpty As Integer

    ' pntCurrent is used to create a Point structure.
    Private pntCurrent As System.Drawing.Point

    ' All of the work takes place in the ConfigureSeating procedure. This
    ' procedure is called by the constructor. See the New procedure in the
    ' Windows Form Designer generated code.
    Private Sub ConfigureSeating(ByVal AircraftType As String)

        ' Variables to store the current seat and the current row.
        Dim pintSeatCurrent, pintRowCurrent As Integer

        ' The Select Case statement configures the airplane based on the
        ' type of airplane. This value is passed to the procedure, and is
        ' obtained from the argument passed through the constructor.
        Select Case AircraftType


            Case "757"
                ' Redimension the arrays containing the check boxes and 
                ' labels based on the current airplane configuration.
                ReDim chkSeats(cint757Seats, cint757Rows)
                ReDim lblRow(cint757Rows)

                ' Define the number of empty seats.
                mintEmpty = cint757Seats * cint757Rows

                ' Create each check box representing a seat.
                For pintSeatCurrent = 0 To cint757Seats - 1
                    For pintRowCurrent = 0 To cint757Rows - 1
                        pntCurrent = New Point((pintSeatCurrent + 1) * cintCheckBoxWidth, _
                            (pintRowCurrent + 1) * cintCheckBoxHeight)
                        Call CreateCheckBox(pintSeatCurrent, pintRowCurrent, pntCurrent)
                    Next
                Next

                ' Create the labels to identify the rows.
                For pintRowCurrent = 0 To cint757Rows - 1
                    Call CreateLabel(pintRowCurrent)
                    lblRow(pintRowCurrent).Left = 120
                    lblRow(pintRowCurrent).Top = (pintRowCurrent + 1) * cintCheckBoxHeight
                    lblRow(pintRowCurrent).Height = 15
                    lblRow(pintRowCurrent).Width = 25
                Next

            Case "777"

                ReDim chkSeats(cint777Seats, cint777Rows)
                ReDim lblRow(cint777Rows)
                mintEmpty = cint777Seats * cint777Rows
                For pintSeatCurrent = 0 To cint777Seats - 1
                    For pintRowCurrent = 0 To cint777Rows - 1
                        pntCurrent = New Point((pintSeatCurrent + 1) * cintCheckBoxWidth, _
                            (pintRowCurrent + 1) * cintCheckBoxHeight)
                        Call CreateCheckBox(pintSeatCurrent, pintRowCurrent, pntCurrent)
                    Next
                Next

                For pintRowCurrent = 0 To cint777Rows - 1
                    Call CreateLabel(pintRowCurrent)

                    lblRow(pintRowCurrent).Left = 220
                    lblRow(pintRowCurrent).Top = (pintRowCurrent + 1) * cintCheckBoxHeight
                    lblRow(pintRowCurrent).Height = 15
                    lblRow(pintRowCurrent).Width = 25
                Next
        End Select

    End Sub

    ' The CreateCheckBox procedure is responsible for actually creating
    ' each CheckBox control instance and adding a reference to the array.
    ' The current seat and row are passed as arguments, along with the 
    ' position of the check box.
    Private Sub CreateCheckBox(ByVal pintSeatCurrent As Integer, ByVal pintRowcurrent As Integer, ByVal pnt As Point)

        ' Create an instance of the CheckBox control and make it visible.
        chkSeats(pintSeatCurrent, pintRowcurrent) = New CheckBox()
        chkSeats(pintSeatCurrent, pintRowcurrent).Visible = True

        ' Define the size of the CheckBox control instance by creating an 
        ' instance of the Size structure and assigning a value to the Size
        ' property.
        chkSeats(pintSeatCurrent, pintRowcurrent).Size = _
            New System.Drawing.Size(cintCheckBoxWidth, cintCheckBoxHeight)

        ' Define the position of the CheckBox control instance.
        chkSeats(pintSeatCurrent, pintRowcurrent).Location = pnt

        ' Add the event handler for the newly created CheckBox control instance. 
        ' The procedure named chkSeats_CheckChanged will handle the CheckedChanged event for
        ' all of the created check boxes.
        AddHandler chkSeats(pintSeatCurrent, pintRowcurrent).CheckedChanged, _
            AddressOf chkseats_CheckedChanged

        ' Finally, add the newly creted CheckBox control instance to the Controls 
        ' collection for the Panel. Note that by adding the control instance to the
        ' Controls collection of the Panel rather than the form, the control instances
        ' will be contained by the Panel. The reason is simple. The CheckBox control
        ' instances will scroll with the Panel instead of the form.
        Me.pnlSeats.Controls.Add(chkSeats(pintSeatCurrent, pintRowcurrent))
    End Sub

    ' The CreateLabel procedure is responsible for actually creating each
    ' Label control instance and adding a reference to the array.
    Private Sub CreateLabel(ByVal pintRowCurrent As Integer)
        lblRow(pintRowCurrent) = New Label()
        lblRow(pintRowCurrent).Visible = True
        lblRow(pintRowCurrent).Text = (pintRowCurrent + 1).ToString()
        Me.pnlSeats.Controls.Add(lblRow(pintRowCurrent))
    End Sub

    ' The CheckedChanged event handler is a multicast event handler and
    ' handles the CheckedChanged event for all of the CheckBox control instances.
    ' The statements in the event handler update the number of full or empty
    ' seats on the airplane.
    Private Sub chkseats_CheckedChanged(ByVal sender As System.Object, ByVal e As System.EventArgs)

        ' Declare a varible to store the CheckBox.
        Dim chkCurrent As System.Windows.Forms.CheckBox

        ' Again, because sender is of type System.Object, explicitly convert
        ' the argument to a check box using the CType function
        chkCurrent = CType(sender, System.Windows.Forms.CheckBox)

        ' If the check box is checked, increment the number of occupied seats
        ' and decrement the number of empty seats. If the check box is not checked,
        ' then do the reverse.
        Select Case chkCurrent.Checked
            Case True
                mintFull += 1
                mintEmpty -= 1
            Case False
                mintFull -= 1
                mintEmpty += 1
        End Select

        ' Display the results in the labels.
        lblFull.Text = mintFull.ToString()
        lblEmpty.Text = mintEmpty.ToString()
    End Sub

    Private Sub btnClose_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClose.Click
        Me.Close()
    End Sub

    ' Uncheck all of the check boxes by enumerating the Controls collection
    ' of the Panel.
    Private Sub btnClear_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClear.Click

        Dim ctlCurrent As Control
        Dim chkCurrent As CheckBox

        ' The For Each loop enumerates the Controls collection for the 
        ' Panel rather than the form.
        For Each ctlCurrent In pnlSeats.Controls
            ' Check that the type of the control instance is a CheckBox. 
            ' Labels are also contained by the Panel. If the control instance
            ' is a CheckBox, then remove the check mark by setting the Checked property
            ' to False.
            If TypeOf (ctlCurrent) Is System.Windows.Forms.CheckBox Then
                chkCurrent = CType(ctlCurrent, System.Windows.Forms.CheckBox)
                chkCurrent.Checked = False
            End If
        Next
        lblFull.Text = ""
        lblEmpty.Text = ""
    End Sub


End Class