form1.frm

1） 文本框的双向作用（即输入与输出） 2） 窗体的双重作用（容器与输出） 3） 事件过程的编写 4） 输入输出的简单实现 5） 窗体、文本框、标签、命令按钮等基本控件的常用属性的动

VERSION 5.00
Begin VB.Form Form1 
   Caption         =   "Form1"
   ClientHeight    =   7860
   ClientLeft      =   60
   ClientTop       =   450
   ClientWidth     =   11190
   LinkTopic       =   "Form1"
   ScaleHeight     =   7860
   ScaleWidth      =   11190
   StartUpPosition =   3  '窗口缺省
   Begin VB.TextBox Text1 
      Alignment       =   1  'Right Justify
      BeginProperty Font 
         Name            =   "宋体"
         Size            =   42
         Charset         =   134
         Weight          =   400
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   855
      Left            =   3480
      TabIndex        =   19
      Top             =   1320
      Width           =   5895
   End
   Begin VB.CommandButton Command1 
      Caption         =   "+"
      Height          =   615
      Index           =   11
      Left            =   6720
      TabIndex        =   18
      Top             =   3600
      Width           =   615
   End
   Begin VB.CommandButton Command1 
      Caption         =   "-"
      Height          =   615
      Index           =   12
      Left            =   8160
      TabIndex        =   17
      Top             =   3480
      Width           =   615
   End
   Begin VB.CommandButton Command1 
      Caption         =   "*"
      Height          =   615
      Index           =   13
      Left            =   6840
      TabIndex        =   16
      Top             =   4680
      Width           =   615
   End
   Begin VB.CommandButton Command1 
      Caption         =   "/"
      Height          =   615
      Index           =   14
      Left            =   8160
      TabIndex        =   15
      Top             =   4800
      Width           =   615
   End
   Begin VB.CommandButton Command1 
      Caption         =   "Mod"
      Height          =   615
      Index           =   15
      Left            =   6840
      TabIndex        =   14
      Top             =   5880
      Width           =   615
   End
   Begin VB.CommandButton Command1 
      Caption         =   "C"
      Height          =   1215
      Index           =   16
      Left            =   9120
      TabIndex        =   13
      Top             =   3600
      Width           =   975
   End
   Begin VB.CommandButton Command1 
      Caption         =   "="
      Height          =   615
      Index           =   17
      Left            =   8280
      TabIndex        =   12
      Top             =   5880
      Width           =   615
   End
   Begin VB.CommandButton Command1 
      Caption         =   "EXIT"
      Height          =   1095
      Index           =   18
      Left            =   9240
      TabIndex        =   11
      Top             =   5760
      Width           =   975
   End
   Begin VB.CommandButton Command1 
      Caption         =   "0"
      Height          =   615
      Index           =   0
      Left            =   1560
      TabIndex        =   10
      Top             =   6240
      Width           =   1575
   End
   Begin VB.CommandButton Command1 
      Caption         =   "1"
      Height          =   615
      Index           =   1
      Left            =   1560
      TabIndex        =   9
      Top             =   3360
      Width           =   615
   End
   Begin VB.CommandButton Command1 
      Caption         =   "2"
      Height          =   615
      Index           =   2
      Left            =   2520
      TabIndex        =   8
      Top             =   3360
      Width           =   615
   End
   Begin VB.CommandButton Command1 
      Caption         =   "3"
      Height          =   615
      Index           =   3
      Left            =   3480
      TabIndex        =   7
      Top             =   3360
      Width           =   615
   End
   Begin VB.CommandButton Command1 
      Caption         =   "4"
      Height          =   615
      Index           =   4
      Left            =   1560
      TabIndex        =   6
      Top             =   4320
      Width           =   615
   End
   Begin VB.CommandButton Command1 
      Caption         =   "5"
      Height          =   615
      Index           =   5
      Left            =   2520
      TabIndex        =   5
      Top             =   4320
      Width           =   615
   End
   Begin VB.CommandButton Command1 
      Caption         =   "6"
      Height          =   615
      Index           =   6
      Left            =   3480
      TabIndex        =   4
      Top             =   4320
      Width           =   615
   End
   Begin VB.CommandButton Command1 
      Caption         =   "7"
      Height          =   615
      Index           =   7
      Left            =   1560
      TabIndex        =   3
      Top             =   5280
      Width           =   615
   End
   Begin VB.CommandButton Command1 
      Caption         =   "8"
      Height          =   615
      Index           =   8
      Left            =   2520
      TabIndex        =   2
      Top             =   5280
      Width           =   615
   End
   Begin VB.CommandButton Command1 
      Caption         =   "9"
      Height          =   615
      Index           =   9
      Left            =   3480
      TabIndex        =   1
      Top             =   5280
      Width           =   615
   End
   Begin VB.CommandButton Command1 
      Caption         =   "."
      Height          =   615
      Index           =   10
      Left            =   3480
      TabIndex        =   0
      Top             =   6240
      Width           =   615
   End
End
Attribute VB_Name = "Form1"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Dim num1, num2 As Double
Dim sum As Double
Dim act, m As Integer
Private Sub Form_Load()
num1 = 0
m = 0
num2 = 0
sum = 0
End Sub
Private Sub Command1_Click(Index As Integer)
Select Case Index
Case 0 To 9
 If m = 1 Then
 Text1.Text = ""
 m = 0
 End If
 If Text1.Text = "" Then
  Text1.Text = CStr(Index)
 Else
 Text1.Text = Text1.Text + CStr(Index)
 End If
Case 10
 If Text1.Text = "" Then
 Text1.Text = "."
 Else
 Text1.Text = Text1.Text + "."
 End If
Case 11
 num1 = CDbl(Text1.Text)
 Text1.Text = ""
 act = 1
Case 12
 num1 = CDbl(Text1.Text)
 Text1.Text = ""
 act = 2
Case 13
 num1 = CDbl(Text1.Text)
 Text1.Text = ""
 act = 3
Case 14
 num1 = CDbl(Text1.Text)
 Text1.Text = ""
 act = 4
Case 15
 num1 = CDbl(Text1.Text)
 Text1.Text = ""
 act = 5
Case 16
 num1 = 0
 num2 = 0
 sum = 0
 Text1.Text = ""
Case 17
 num2 = CDbl(Text1.Text)
 m = 1
 Select Case act
 Case 1
  sum = num1 + num2
Case 2
sum = num1 - num2
Case 3
sum = num1 * num2
Case 4
sum = num1 / num2
Case 5
sum = num1 Mod num2
 End Select
 sum = Round(sum, 4)
 Text1.Text = ""
 Text1.Text = CStr(sum)
Case 18
 End
End Select

End Sub