谁能用VB做一个像WINDOWS自带的计算器，麻烦给我一下源代码

问题描述：

需要能实现四则运算的，不过只用加减乘除运算，当输入表达式时，乘除优先，输入方式为点击式。谢谢！

问题解答：

保存为 任务名称.frm
VERSION 5.00
Begin VB.Form Form1
Caption = "计算机"
ClientHeight = 4230
ClientLeft = 60
ClientTop = 750
ClientWidth = 3165
LinkTopic = "Form1"
MaxButton = 0 'False
MinButton = 0 'False
ScaleHeight = 4230
ScaleWidth = 3165
StartUpPosition = 2 '屏幕中心
Begin VB.Frame Frame1
Height = 3495
Left = 120
TabIndex = 1
Top = 600
Width = 2895
Begin VB.CommandButton cmdResult
Caption = "="
BeginProperty Font
Name = "宋体"
Size = 12
Charset = 134
Weight = 400
Underline = 0 'False
Italic = 0 'False
Strikethrough = 0 'False
EndProperty
Height = 375
Left = 1080
TabIndex = 20
Top = 3000
Width = 1695
End
Begin VB.CommandButton cmdOff
Caption = "OFF"
Height = 375
Left = 1560
TabIndex = 19
Top = 240
Width = 495
End
Begin VB.CommandButton cmdCE
Caption = "CE"
Height = 375
Left = 2280
TabIndex = 18
Top = 240
Width = 495
End
Begin VB.CommandButton cmdchu
Caption = "/"
Height = 375
Left = 2280
TabIndex = 17
Top = 2520
Width = 495
End
Begin VB.CommandButton cmdjia
Caption = "+"
Height = 375
Left = 2280
TabIndex = 16
Top = 720
Width = 495
End
Begin VB.CommandButton cmd0
Caption = "0"
Height = 375
Left = 840
TabIndex = 15
Top = 2520
Width = 495
End
Begin VB.CommandButton cmd6
Caption = "6"
Height = 375
Left = 1560
TabIndex = 14
Top = 1320
Width = 495
End
Begin VB.CommandButton cmd8
Caption = "8"
Height = 375
Left = 840
TabIndex = 13
Top = 720
Width = 495
End
Begin VB.CommandButton cmd4
Caption = "4"
Height = 375
Left = 120
TabIndex = 12
Top = 1320
Width = 495
End
Begin VB.CommandButton cmd9
Caption = "9"
Height = 375
Left = 1560
TabIndex = 11
Top = 720
Width = 495
End
Begin VB.CommandButton cmd2
Caption = "2"
Height = 375
Left = 840
TabIndex = 10
Top = 1920
Width = 495
End
Begin VB.CommandButton cmdjian
Caption = "-"
Height = 375
Left = 2280
TabIndex = 9
Top = 1320
Width = 495
End
Begin VB.CommandButton cmdPoint
Caption = "."
BeginProperty Font
Name = "宋体"
Size = 12
Charset = 134
Weight = 400
Underline = 0 'False
Italic = 0 'False
Strikethrough = 0 'False
EndProperty
Height = 375
Left = 1560
TabIndex = 8
Top = 2520
Width = 495
End
Begin VB.CommandButton cmdcheng
Caption = "*"
Height = 375
Left = 2280
TabIndex = 7
Top = 1920
Width = 495
End
Begin VB.CommandButton cmd5
Caption = "5"
Height = 375
Left = 840
TabIndex = 6
Top = 1320
Width = 495
End
Begin VB.CommandButton cmd3
Caption = "3"
Height = 375
Left = 1560
TabIndex = 5
Top = 1905
Width = 495
End
Begin VB.CommandButton cmd1
Caption = "1"
Height = 375
Left = 120
TabIndex = 4
Top = 1920
Width = 495
End
Begin VB.CommandButton cmd7
Caption = "7"
Height = 375
Left = 120
TabIndex = 3
Top = 720
Width = 495
End
Begin VB.CommandButton cmdChange
Caption = "+/-"
Height = 375
Left = 120
TabIndex = 2
Top = 2520
Width = 495
End
End
Begin VB.TextBox txt
Alignment = 1 'Right Justify
Enabled = 0 'False
BeginProperty Font
Name = "宋体"
Size = 10.5
Charset = 134
Weight = 400
Underline = 0 'False
Italic = 0 'False
Strikethrough = 0 'False
EndProperty
Height = 375
Left = 120
Locked = -1 'True
TabIndex = 0
Top = 120
Width = 2895
End
Begin VB.Menu meuFile
Caption = "文件(&F)"
Begin VB.Menu meuExit
Caption = "退出(&X)"
Shortcut = ^X
End
End
End
Attribute VB_Name = "Form1"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Dim XiaoShu As Boolean
'在窗体变量中声明一个布尔值来判断是否按下了小数点键，防止txt中出现多个小数。如果已经输入了小数点则Xiaoshu为True，否则为False

Dim FuHao As Byte
'声明一个Byte来记录我们按下了什么符号，1为"+"，2为"-"，3为"*"，4为"/"

Dim FirstNumber As Double
'声明一个变量来记录操作数的第一个数,如A+B，那么FirstNumber来记下A的值。

Dim DengHao As Boolean
'声明一个变量来记录是否按下了=号，如果按下了则为True

Private Sub cmd0_Click()
If txt.Text <> "" Then txt.Text = txt.Text + "0" '防止多个0在文本中出现
End Sub

Private Sub cmd1_Click() '按下1时
If Not DengHao Then '没按下等号
txt.Text = txt.Text + "1"
Else
txt.Text = "1" '按下了等号
DengHao = False
End If
End Sub

Private Sub cmd2_Click() '按下2时
If Not DengHao Then '没按下等号
txt.Text = txt.Text + "2"
Else
txt.Text = "2" '按下了等号
DengHao = False
End If
End Sub

Private Sub cmd3_click() '按下3时
If Not DengHao Then '没按下等号
txt.Text = txt.Text + "3"
Else
txt.Text = "3" '按下了等号
DengHao = False
End If
End Sub

Private Sub cmd4_Click() '按下4时
If Not DengHao Then '没按下等号
txt.Text = txt.Text + "4"
Else
txt.Text = "4" '按下了等号
DengHao = False
End If
End Sub

Private Sub cmd5_Click() '按下5时
If Not DengHao Then '没按下等号
txt.Text = txt.Text + "5"
Else
txt.Text = "5" '按下了等号
DengHao = False
End If
End Sub

Private Sub cmd6_Click() '按下6时
If Not DengHao Then '没按下等号
txt.Text = txt.Text + "6"
Else
txt.Text = "6" '按下了等号
DengHao = False
End If
End Sub

Private Sub cmd7_Click() '按下7时
If Not DengHao Then '没按下等号
txt.Text = txt.Text + "7"
Else
txt.Text = "7" '按下了等号
DengHao = False
End If
End Sub

Private Sub cmd8_Click() '按下8时
If Not DengHao Then '没按下等号
txt.Text = txt.Text + "8"
Else
txt.Text = "8" '按下了等号
DengHao = False
End If
End Sub

Private Sub cmd9_Click() '按下9时
If Not DengHao Then '没按下等号
txt.Text = txt.Text + "9"
Else
txt.Text = "9" '按下了等号
DengHao = False
End If
End Sub

Private Sub cmdCE_Click()
txt.Text = ""
XiaoShu = False
End Sub

Private Sub cmdChange_Click()
If (Sgn(Val(txt.Text))) = 1 Then txt.Text = "-" + txt.Text: Exit Sub '用Sgn来判断txt文本框内的值的符号。大于0的话就在前面加上"-"
If (Sgn(Val(txt.Text))) = -1 Then txt.Text = Abs(Val(txt.Text)) 'txt文本框的文本为大于0的数txt前面的"-"去掉。
End Sub

Private Sub cmdcheng_Click()
FirstNumber = Val(txt.Text)
FuHao = 3
txt.Text = ""
XiaoShu = False
End Sub

Private Sub cmdchu_Click()
FirstNumber = Val(txt.Text)
FuHao = 4
txt.Text = ""
XiaoShu = False
End Sub

Private Sub cmdjia_Click()
FirstNumber = Val(txt.Text)
FuHao = 1
txt.Text = ""
XiaoShu = False
End Sub

Private Sub cmdjian_Click()
FirstNumber = Val(txt.Text)
FuHao = 2
txt.Text = ""
XiaoShu = False
End Sub

Private Sub cmdOff_Click()
End
End Sub

Private Sub cmdPoint_Click()
If txt.Text = "" Then txt.Text = "0"
If Not XiaoShu Then '当我们以前没有按下小数点键时在txt中加上小数点
txt.Text = txt.Text + "."
XiaoShu = True
End If
End Sub

Private Sub cmdResult_Click()
If FuHao = 1 Then '按下了+号
txt.Text = FirstNumber + Val(txt.Text)
End If
If FuHao = 2 Then '按下了-号
txt.Text = FirstNumber - Val(txt.Text)
End If
If FuHao = 3 Then '按下了*号
txt.Text = FirstNumber * Val(txt.Text)
End If
If FuHao = 4 Then '按下了、号
txt.Text = FirstNumber / Val(txt.Text)
End If
DengHao = True '记录下按了=号
XiaoShu = False
End Sub

Private Sub meuExit_Click()
End
End Sub

Option Explicit

Private StoredValue As Double

Private Const opNone = 0
Private Const opAdd = 1
Private Const opSubtract = 2
Private Const opMultiply = 3
Private Const opDivide = 4
Private Operator As Integer

Private NewEntry As Boolean

'删除最后的字符
Private Sub DeleteCharacter()
Dim txt As String
Dim min_len As Integer

txt = txtDisplay.Text
If Left$(txt, 1) = "-" Then
min_len = 2
Else
min_len = 1
End If

If Len(txt) > min_len Then
txtDisplay.Text = Left$(txt, Len(txt) - 1)
Else
txtDisplay.Text = "0"
End If
End Sub

'清除显示内容，保存运算符
Private Sub cmdClear_Click()
cmdClearEntry_Click
StoredValue = 0
Operator = opNone
End Sub

'清除显示内容
Private Sub cmdClearEntry_Click()
txtDisplay.Text = ""
End Sub

' 显示小数点
Private Sub cmdDecimal_Click()
If InStr(txtDisplay.Text, ".") Then
Beep
Else
If NewEntry Then
txtDisplay.Text = "."
NewEntry = False
Else
txtDisplay.Text = txtDisplay.Text & "."
End If
End If
End Sub

'计算上一操作符的运算结果
Private Sub cmdEquals_Click()
Dim new_value As Double

If txtDisplay.Text = "" Then
new_value = 0
Else
new_value = CDbl(txtDisplay.Text)
End If
Select Case Operator
Case opNone
StoredValue = new_value
Case opAdd
StoredValue = StoredValue + new_value
Case opSubtract
StoredValue = StoredValue - new_value
Case opMultiply
StoredValue = StoredValue * new_value
Case opDivide
StoredValue = StoredValue / new_value
End Select
Operator = opNone
NewEntry = True
txtDisplay.Text = Format$(StoredValue)
End Sub

' 显示数字
Private Sub cmdNumber_Click(Index As Integer)
If NewEntry Then
txtDisplay.Text = Format$(Index)
NewEntry = False
Else
txtDisplay.Text = txtDisplay.Text & Format$(Index)
End If
End Sub

Private Sub cmdOperator_Click(Index As Integer)
cmdEquals_Click
Operator = Index
NewEntry = True
End Sub
'改变符号
Private Sub cmdPlusMinus_Click()
If NewEntry Then
txtDisplay.Text = "-"
ElseIf Left$(txtDisplay.Text, 1) = "-" Then
txtDisplay.Text = Right$(txtDisplay.Text, 2)
Else
txtDisplay.Text = "-" & txtDisplay.Text
End If
End Sub

'处理键盘按键
Private Sub Form_KeyPress(KeyAscii As Integer)
txtDisplay_KeyPress KeyAscii
End Sub

Private Sub Form_KeyUp(KeyCode As Integer, Shift As Integer)
txtDisplay_KeyUp KeyCode, Shift
End Sub

Private Sub txtDisplay_Change()
txtDisplay.SelStart = Len(txtDisplay.Text)
End Sub

Private Sub txtDisplay_GotFocus()
txtDisplay_Change
End Sub

Private Sub txtDisplay_KeyPress(KeyAscii As Integer)
Dim ch As String

ch = Chr$(KeyAscii)
Select Case ch
Case "0"
cmdNumber_Click 0
Case "1"
cmdNumber_Click 1
Case "2"
cmdNumber_Click 2
Case "3"
cmdNumber_Click 3
Case "4"
cmdNumber_Click 4
Case "5"
cmdNumber_Click 5
Case "6"
cmdNumber_Click 6
Case "7"
cmdNumber_Click 7
Case "8"
cmdNumber_Click 8
Case "9"
cmdNumber_Click 9
Case "*", "x", "X"
cmdOperator_Click opMultiply
Case "+"
cmdOperator_Click opAdd
Case vbCrLf, vbCr, "="
cmdEquals_Click
Case "-"
cmdOperator_Click opSubtract
Case "."
cmdDecimal_Click
Case "/"
cmdOperator_Click opDivide
Case "C", "c"
cmdClearEntry_Click
End Select

KeyAscii = 0
End Sub

Private Sub txtDisplay_KeyUp(KeyCode As Integer, Shift As Integer)
Select Case KeyCode
Case vbKeyNumpad0
cmdNumber_Click 0
Case vbKeyNumpad1
cmdNumber_Click 1
Case vbKeyNumpad2
cmdNumber_Click 2
Case vbKeyNumpad3
cmdNumber_Click 3
Case vbKeyNumpad4
cmdNumber_Click 4
Case vbKeyNumpad5
cmdNumber_Click 5
Case vbKeyNumpad6
cmdNumber_Click 6
Case vbKeyNumpad7
cmdNumber_Click 7
Case vbKeyNumpad8
cmdNumber_Click 8
Case vbKeyNumpad9
cmdNumber_Click 9
Case vbKeyMultiply
cmdOperator_Click opMultiply
Case vbKeyAdd
cmdOperator_Click opAdd
Case vbKeySeparator
cmdEquals_Click
Case vbKeySubtract
cmdOperator_Click opSubtract
Case vbKeyDecimal
cmdDecimal_Click
Case vbKeyDivide
cmdOperator_Click opDivide
Case vbKeyBack, vbKeyDelete
DeleteCharacter
End Select
KeyCode = 0
End Sub