form1.vb

Source code for VB.NET book - Chapter 2

Public Class Form1
    Inherits System.Windows.Forms.Form

#Region " Windows 窗体设计器生成的代码 "

    Public Sub New()
        MyBase.New()

        '该调用是 Windows 窗体设计器所必需的。
        InitializeComponent()

        '在 InitializeComponent() 调用之后添加任何初始化

    End Sub

    '窗体重写 dispose 以清理组件列表。
    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub

    'Windows 窗体设计器所必需的
    Private components As System.ComponentModel.IContainer

    '注意: 以下过程是 Windows 窗体设计器所必需的
    '可以使用 Windows 窗体设计器修改此过程。
    '不要使用代码编辑器修改它。
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    Friend WithEvents TextBox2 As System.Windows.Forms.TextBox
    Friend WithEvents TextBox3 As System.Windows.Forms.TextBox
    Friend WithEvents Label1 As System.Windows.Forms.Label
    Friend WithEvents TextBox4 As System.Windows.Forms.TextBox
    Friend WithEvents Button1 As System.Windows.Forms.Button
    Friend WithEvents Button2 As System.Windows.Forms.Button
    Friend WithEvents Label2 As System.Windows.Forms.Label
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.TextBox1 = New System.Windows.Forms.TextBox
        Me.TextBox2 = New System.Windows.Forms.TextBox
        Me.TextBox3 = New System.Windows.Forms.TextBox
        Me.Label1 = New System.Windows.Forms.Label
        Me.TextBox4 = New System.Windows.Forms.TextBox
        Me.Button1 = New System.Windows.Forms.Button
        Me.Button2 = New System.Windows.Forms.Button
        Me.Label2 = New System.Windows.Forms.Label
        Me.SuspendLayout()
        '
        'TextBox1
        '
        Me.TextBox1.Location = New System.Drawing.Point(8, 48)
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.Size = New System.Drawing.Size(72, 20)
        Me.TextBox1.TabIndex = 0
        Me.TextBox1.Text = ""
        '
        'TextBox2
        '
        Me.TextBox2.Location = New System.Drawing.Point(96, 48)
        Me.TextBox2.Name = "TextBox2"
        Me.TextBox2.Size = New System.Drawing.Size(32, 20)
        Me.TextBox2.TabIndex = 1
        Me.TextBox2.Text = ""
        '
        'TextBox3
        '
        Me.TextBox3.Location = New System.Drawing.Point(136, 48)
        Me.TextBox3.Name = "TextBox3"
        Me.TextBox3.Size = New System.Drawing.Size(88, 20)
        Me.TextBox3.TabIndex = 2
        Me.TextBox3.Text = ""
        '
        'Label1
        '
        Me.Label1.Font = New System.Drawing.Font("Microsoft Sans Serif", 14.25!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Label1.Location = New System.Drawing.Point(232, 48)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(24, 16)
        Me.Label1.TabIndex = 3
        Me.Label1.Text = "="
        '
        'TextBox4
        '
        Me.TextBox4.Location = New System.Drawing.Point(264, 48)
        Me.TextBox4.Name = "TextBox4"
        Me.TextBox4.Size = New System.Drawing.Size(72, 20)
        Me.TextBox4.TabIndex = 4
        Me.TextBox4.Text = ""
        '
        'Button1
        '
        Me.Button1.Location = New System.Drawing.Point(72, 96)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size(80, 24)
        Me.Button1.TabIndex = 5
        Me.Button1.Text = "计  算"
        '
        'Button2
        '
        Me.Button2.Location = New System.Drawing.Point(208, 96)
        Me.Button2.Name = "Button2"
        Me.Button2.Size = New System.Drawing.Size(72, 24)
        Me.Button2.TabIndex = 6
        Me.Button2.Text = "退  出"
        '
        'Label2
        '
        Me.Label2.Font = New System.Drawing.Font("Microsoft Sans Serif", 12.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(0, Byte))
        Me.Label2.Location = New System.Drawing.Point(24, 136)
        Me.Label2.Name = "Label2"
        Me.Label2.Size = New System.Drawing.Size(320, 112)
        Me.Label2.TabIndex = 7
        Me.Label2.Text = "程序说明：本程序是一个简单的计算器，请在第一个和第三个文本框中输入数值，在第二个文本框中输入运算符（""＋""（加法）、""－""（减法）、""/""（除法）、""*""（乘法）" & _
        "）"
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.ClientSize = New System.Drawing.Size(360, 266)
        Me.Controls.Add(Me.Label2)
        Me.Controls.Add(Me.Button2)
        Me.Controls.Add(Me.Button1)
        Me.Controls.Add(Me.TextBox4)
        Me.Controls.Add(Me.Label1)
        Me.Controls.Add(Me.TextBox3)
        Me.Controls.Add(Me.TextBox2)
        Me.Controls.Add(Me.TextBox1)
        Me.Name = "Form1"
        Me.Text = "计算器"
        Me.ResumeLayout(False)

    End Sub

#End Region

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim a, b, c As Double
        Dim op As Char
        a = CDbl(TextBox1.Text)
        b = CDbl(TextBox3.Text)
        op = CChar(TextBox2.Text)
        Select Case op
            Case "+"
                c = a + b
            Case "-"
                c = a - b
            Case "/"
                c = a / b
            Case "*"
                c = a * b
            Case Else
                GoTo errhandler
        End Select
        TextBox4.Text = CStr(c)
errhandler:
        Exit Sub
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        End
    End Sub
End Class