利用API 實現字符串表達式的計算

下面實現字符串表達式計算代碼由筆者收藏的本論壇代碼改編，記不清是哪位網友提供的了，非常感謝。

Option Explicit
Private Declare Function EbExecuteLine Lib "vba6.dll" (ByVal pStringToExec As Long, ByVal Unknownn1 As Long, ByVal Unknownn2 As Long, ByVal fCheckOnly As Long) As Long

Private Function ExecuteLine(sCode As String, Optional fCheckOnly As Boolean) As Boolean
    ExecuteLine = EbExecuteLine(StrPtr(sCode), 0&, 0&, Abs(fCheckOnly)) = 0
End Function

Sub calc(ByVal x As String)
Dim result
ExecuteLine "dim x as double"
ExecuteLine "x= " & x
ExecuteLine "clipboard.settext x"
result = Clipboard.GetText
MsgBox x & "=" & result
Set result = Nothing
End Sub

Private Sub Command1_Click()
calc Text1
End Sub

Private Sub Form_Load()
Text1.Text = "1+2*3-4/5"
End Sub

原文轉自：http://www.anti-gravitydesign.com