三个变量 分别存储 操作数 被操作数 和操作

　　根据对按钮的点击分别设置三个变量的值

　　创建一个窗口 画一个 文本框Text1

　　画一个按钮 Command1 设Index属性为0 粘贴如下代码

　　Option Explicit

　　Private dblOper1 As Double, dblOper2 As Double

　　Private lpType As String, b As Boolean

　　Private Sub Command1_Click(Index As Integer)

　　Select Case Index

　　Case 3, 7, 11, 15 '+-*/

　　lpType = Command1(Index).Caption

　　Me.Caption = CStr(dblOper1) & lpType

　　Text1.Text = ""

　　b = True

　　Case 12 '按下的是清屏

　　Text1.Text = ""

　　b = False

　　dblOper1 = 0

　　dblOper2 = 0

　　Case 14 '按下的是等于

　　Me.Caption = CStr(dblOper1) & lpType & CStr(dblOper2) & "="

　　Text1.Text = Calc()

　　b = False

　　dblOper1 = 0

　　dblOper2 = 0

　　Case Else '按下的是数字

　　Text1.Text = Text1.Text & Command1(Index).Caption

　　If b = False Then

　　dblOper1 = CDbl(Text1.Text)

　　Else

　　dblOper2 = CDbl(Text1.Text)

　　End If

　　End Select

　　End Sub

　　Public Function Calc() As String

　　Select Case lpType

　　Case "+"

　　Calc = CStr(dblOper1 + dblOper2)

　　Case "-"

　　Calc = CStr(dblOper1 - dblOper2)

　　Case "*"

　　Calc = CStr(dblOper1 * dblOper2)

　　Case "/"

　　Calc = CStr(dblOper1 / dblOper2)

　　End Select

　　End Function

　　Private Sub Form_Load()

　　Dim i As Integer

　　Me.Width = 4635

　　Me.Height = 2505

　　Text1.Left = 120

　　Text1.Top = 120

　　Text1.Width = 4275

　　Text1.Height = 315

　　Text1.Text = ""

　　Command1(0).Left = 120

　　Command1(0).Top = 480

　　Command1(0).Width = 1035

　　Command1(0).Height = 315

　　For i = 1 To 15

　　Load Command1(i)

　　If (i Mod 4) <> 0 Then

　　Command1(i).Left = Command1(i - 1).Left + 1080

　　Command1(i).Top = Command1(i - 1).Top

　　Else

　　Command1(i).Left = Command1(0).Left

　　Command1(i).Top = Command1(i - 4).Top + 360

　　End If

　　Command1(i).Visible = True

　　Next i

　　Command1(0).Caption = "1"

　　Command1(1).Caption = "2"

　　Command1(2).Caption = "3"

　　Command1(3).Caption = "+"

　　Command1(4).Caption = "4"

　　Command1(5).Caption = "5"

　　Command1(6).Caption = "6"

　　Command1(7).Caption = "-"

　　Command1(8).Caption = "7"

　　Command1(9).Caption = "8"

　　Command1(10).Caption = "9"

　　Command1(11).Caption = "*"

　　Command1(12).Caption = "C"

　　Command1(13).Caption = "0"

　　Command1(14).Caption = "="

　　Command1(15).Caption = "/&q