夕阳醉了's Blog

Option Explicit
Dim a As Double, b As Double, c As Double
'a是最终结果,b是优先级结果,c是录入变量
Dim idx As Integer
Dim PreMode As String, JustMode As String, CurMode As String

Private Sub ComAC_Click() '清空按钮
   a = 0
   b = 0
   c = 0
   Text1.Text = "0"
   idx = 1
   PreMode = ""
   JustMode = ""
   CurMode = ""
End Sub

Private Sub ComAdd_Click() '加法
   On Error GoTo er
   c = Val(Text1.Text)
   CurMode = "+"
   If PreMode = "" Then
       If JustMode = "" Then
           a = c
       ElseIf JustMode = "+" Then
           a = a + c
       ElseIf JustMode = "-" Then
           a = a - c
       ElseIf JustMode = "*" Then
           a = a * c
       ElseIf JustMode = "/" Then
           a = a / c
       End If
   ElseIf PreMode = "+" Then
       If JustMode = "*" Then
           a = a + b * c
       ElseIf JustMode = "/" Then
           a = a + b / c
       End If
   ElseIf PreMode = "-" Then
       If JustMode = "*" Then
           a = a - b * c
       ElseIf JustMode = "/" Then
           a = a - b / c
       End If
   End If

   Text1.Text = CStr(a)
   PreMode = ""
   JustMode = CurMode
   idx = 2
   Exit Sub
er:
   MsgBox Err.Description, vbCritical, "Error", vbCritical, "Error"
   Call ComAC_Click
   Exit Sub
End Sub

Private Sub ComBak_Click() '退格
   Text1.Text = Left(Text1.Text, Len(Text1.Text) - 1)
   If Len(Text1.Text) = 0 Then
       Text1.Text = "0"
   End If
End Sub

Private Sub ComDiv_Click() '除法
   On Error GoTo er
   c = Val(Text1.Text)
   CurMode = "/"
   If PreMode = "" Then
       If JustMode = "" Then
           a = c
           Text1.Text = CStr(a)
       ElseIf JustMode = "+" Or JustMode = "-" Then
           b = c
           PreMode = JustMode
       ElseIf JustMode = "*" Then
           a = a * c
           Text1.Text = CStr(a)
       ElseIf JustMode = "/" Then
           a = a / c
           Text1.Text = CStr(a)
       End If
   ElseIf PreMode = "+" Then
       If JustMode = "*" Then
           b = b * c
       ElseIf JustMode = "/" Then
           b = b / c
       End If
   ElseIf PreMode = "-" Then
       If JustMode = "*" Then
           b = b * c
       ElseIf JustMode = "/" Then
           b = b / c
       End If
   End If
   
   JustMode = CurMode
   idx = 2
   Exit Sub
er:
   MsgBox Err.Description, vbCritical, "Error"
   Call ComAC_Click
   Exit Sub
End Sub

Private Sub ComDot_Click() '小数点
   If idx = 1 Then
       If InStr(1, Text1.Text, ".") = 0 Then
           Text1.Text = Text1.Text + "."
       End If
   Else
       Text1.Text = "0."
   End If
   idx = 1
End Sub

Private Sub ComEqu_Click() '等号
   On Error GoTo er
   c = Val(Text1.Text)
   If PreMode = "" Then
       If JustMode = "+" Then
           a = a + c
       ElseIf JustMode = "-" Then
           a = a - c
       ElseIf JustMode = "*" Then
           a = a * c
       ElseIf JustMode = "/" Then
           a = a / c
       End If
   ElseIf PreMode = "+" Then
       If JustMode = "*" Then
           a = a + b * c
       ElseIf JustMode = "/" Then
           a = a + b / c
       End If
   ElseIf PreMode = "-" Then
       If JustMode = "*" Then
           a = a - b * c
       ElseIf JustMode = "/" Then
           a = a - b / c
       End If
   End If
   
   Text1.Text = CStr(a)
   a = 0
   b = 0
   c = 0
   PreMode = ""
   JustMode = ""
   CurMode = ""
   
   idx = 2
   Exit Sub
er:
   MsgBox Err.Description, vbCritical, "Error"
   Call ComAC_Click
   Exit Sub
End Sub

Private Sub ComMul_Click() '乘号
   On Error GoTo er
   c = Val(Text1.Text)
   CurMode = "*"
   If PreMode = "" Then
       If JustMode = "" Then
           a = c
           Text1.Text = CStr(a)
       ElseIf JustMode = "+" Or JustMode = "-" Then
           b = c
           PreMode = JustMode
       ElseIf JustMode = "*" Then
           a = a * c
           Text1.Text = CStr(a)
       ElseIf JustMode = "/" Then
           a = a / c
           Text1.Text = CStr(a)
       End If
   ElseIf PreMode = "+" Then
       If JustMode = "*" Then
           b = b * c
       ElseIf JustMode = "/" Then
           b = b / c
       End If
   ElseIf PreMode = "-" Then
       If JustMode = "*" Then
           b = b * c
       ElseIf JustMode = "/" Then
           b = b / c
       End If
   End If
   
   
   JustMode = CurMode
   idx = 2
   Exit Sub
er:
   MsgBox Err.Description, vbCritical, "Error"
   Call ComAC_Click
   Exit Sub
End Sub

Private Sub ComNum_Click(Index As Integer) '数字键入
   If idx = 1 Then
       If Text1.Text = "0" Then
           Text1.Text = CStr(Index)
       Else
           Text1.Text = Text1.Text + CStr(Index)
       End If
   Else
       Text1.Text = CStr(Index)
   End If
   idx = 1
End Sub

Private Sub ComOff_Click()
   Unload Me
End Sub

Private Sub ComPN_Click() '正负号
   If Text1.Text = "0" Then
       Text1.Text = "-"
   Else
       If InStr(1, Text1.Text, "-") = 0 Then
           Text1.Text = "-" + Text1.Text
       Else
           Text1.Text = Right(Text1.Text, Len(Text1.Text) - 1)
       End If
   End If
   idx = 1
End Sub

Private Sub ComSub_Click() '减法
   On Error GoTo er
   c = Val(Text1.Text)
   CurMode = "-"
   If PreMode = "" Then
       If JustMode = "" Then
           a = c
       ElseIf JustMode = "+" Then
           a = a + c
       ElseIf JustMode = "-" Then
           a = a - c
       ElseIf JustMode = "*" Then
           a = a * c
       ElseIf JustMode = "/" Then
           a = a / c
       End If
   ElseIf PreMode = "+" Then
       If JustMode = "*" Then
           a = a + b * c
       ElseIf JustMode = "/" Then
           a = a + b / c
       End If
   ElseIf PreMode = "-" Then
       If JustMode = "*" Then
           a = a - b * c
       ElseIf JustMode = "/" Then
           a = a - b / c
       End If
   End If

   Text1.Text = CStr(a)
   PreMode = ""
   JustMode = CurMode
   idx = 2
   Exit Sub
er:
   MsgBox Err.Description, vbCritical, "Error"
   Call ComAC_Click
   Exit Sub
End Sub

Private Sub Form_Load()
   '赋上初值
   PreMode = ""
   JustMode = ""
   CurMode = ""
   a = 0
   b = 0
   c = 0
   idx = 1
End Sub
Private Sub Text1_Change()
   If Val(Text1.Text) < 1 And Val(Text1.Text) > 0 And Left(Text1.Text, 1) <> "0" Then
       Text1.Text = "0" & Text1.Text
   End If
End Sub