Dim x#, y#, op$
Private Sub Command1_Click(Index As Integer)
Select Case Index
Case 0 To 9
    Me.Text1.Text = Me.Text1.Text & (Index).Caption
    Case 10, 12, 13
    x = Val(Me.Text1.Text)
    Me.Text1.Text = ""
    If Index = 10 Then op = "+"
    If Index = 12 Then op = "X"
    If Index = 13 Then op = "/"
    Case 11
    If Text1 = "" Then
    Text1 = "-"
    Else
    x = Val(Me.Text1.Text)
    Me.Text1.Text = ""
    If Index = 11 Then op = "-"
    End If
   
    Case 15
    y = Val(Text1)
    If op = "+" Then Text1 = x + y
    If op = "X" Then Text1 = x * y
    If op = "/" Then Text1 = x / y
    If op = "-" Then Text1 = x - y
   
    Case 14
    If InStr(Text1, ".") = 0 Then Me.Text1.Text = Me.Text1.Text & (Index).Caption
    Case 16
   Text1 = Left(Text1, Len(Text1) - 1)
   Case 17
   If Val(Text1) > 0 Then
   
   Text1 = Val(Log(Text1))
   Else
   Text1 = "底数必须大于零"
   End If
   Case 18
   Text1 = Text1 * Text1
   Case 19
   If InStr(Text1, "-") = 0 Then
   Text1 = Sqr(Text1)
   Else
   Text1 = "被开方数不能小于零"
   End If
   Case 20
   Text1 = ""
   Case 21
   Text1 = Val(Sin(Val((Text1) * 3.14159265358979 / 180)))
   Case 22
   Text1 = Val(Cos(Val((Text1) * 3.14159265358979 / 180)))
   Case 23
   Text1 = Val(Tan(Val((Text1) * 3.14159265358979 / 180)))
   Case 24
   Text1 = Val(Atn(Val((Text1) * 3.14159265358979 / 180)))
    End Select
End Sub

我也遇到过，学习了