vb设计计算器.doc

计算器的设计

Option Explicit
Dim str1 As String
Dim str2 As String
Dim strtemp As String
Dim blnStatus As Boolean
Dim intOperate As Integer
Dim strtemp1 As String

Private Sub cmdBack_Click()
If Not blnStatus Then strtemp = str1 Else strtemp = str2
If Len(strtemp) > 0 Then strtemp = Left(strtemp, Len(strtemp) - 1)
txtDisplay = strtemp
If Not blnStatus Then str1 = strtemp Else str2 = strtemp
End Sub

Private Sub cmdmc_Click()
cmdmstore.Caption = ""
txtDisplay.Text = strtemp1
str1 = ""
blnStatus = False
End Sub

Private Sub cmdmr_Click()
txtDisplay.Text = strtemp1
str1 = ""
blnStatus = False
End Sub

Private Sub cmdms_Click()
cmdmstore.Caption = "m"
strtemp1 = str1
str1 = ""
blnStatus = False
End Sub

Private Sub cmdCalc_Click(Index As Integer)
str2 = ""
txtDisplay.Text = ""
blnStatus = True
intOperate = Index
End Sub

Private Sub cmdEqual_Click(Index As Integer)
If Len(Trim(str1)) = 0 Or Len(Trim(str1)) = 0 Then
blnStatus = False
Exit Sub
End If
Dim dbl1 As Double
Dim dbl2 As Double
dbl1 = Val(str1)
dbl2 = Val(str2)
Select Case intOperate
Case 0
txtDisplay.Text = dbl1 + dbl2
Case 1
txtDisplay.Text = dbl1 - dbl2
Case 2
txtDisplay.Text = dbl1 * dbl2
Case 3
If dbl2 = 0 Then
MsgBox "除数不能为零！", 16, "计算器"
Exit Sub
End If
txtDisplay.Text = dbl1 / dbl2
End Select
blnStatus = False
str1 = ""
str2 = ""
End Sub

Private Sub cmdM_Click(Index As Integer)
If Len(Trim(str1)) = 0 Or Len(Trim(strtemp1)) = 0 Then
blnStatus = False
Exit Sub
End If
Dim dbl1 As Double
Dim dbl2 As Double
dbl1 = Val(str1)
dbl2 = Val(strtemp1)
strtemp1 = dbl1 + dbl2
If Len(strtemp1) > 0 And Left(strtemp1, 1) = "" Then
strtemp = "0" & strtemp
End If
blnStatus = True
str1 = strtemp1
str2 = ""
End Sub

Private Sub cmdNumber_Click(Index As Integer)
If Not blnStatus Then strtemp = str1 Else strtemp = str2
If Index < 10 Then
strtemp = strtemp + CStr(Index)
Else
If InStr(strtemp, ".") = 0 Then strtemp = strtemp + "."
End If
If Len(strtemp) > 1 And Left(strtemp, 1) = "0" And Mid(strtemp, 2, 1) <> "." Then
strtemp = Right(strtemp, Len(strtemp) - 1)
End If
txtDisplay.Text = strtemp
If Not blnStatus Then str1 = strtemp Else str2 = strtemp
End Sub

Private Sub cmdPN_Click()
If Not blnStatus Then strtemp = str1 Else strtemp = str2
If Len(strtemp) > 0 And Left(strtemp, 1) = "-" Then
strtemp = Right(strtemp, Len(strtemp) - 1)
Else
strtemp = "-" & strtemp
End If
txtDisplay = strtemp
If Not blnStatus Then str1 = strtemp Else str2 = strtemp
End Sub