VB中如何把字符串表达式的值取出来

leyear

遇到这样的问题,在数据库的保存的是变量表达式,比如  a+b+(c/d)

现在我知道,abcd 的值,也就是得到串"1+2+5/2"  但却不知道怎么把这个表达串的值取出来

leyear

哈哈,我知道了,自己回答吧
Public Function Test(ByVal Expression As String) As Single
    On Error GoTo ErrorHandle
    Dim domSource               As New DOMDocument
    Dim domStyleSheet           As New DOMDocument
    Dim domResult               As New DOMDocument
    Dim str                     As String

    str = "<?xml version='1.0' encoding='GB2312'?>" + vbCrLf
    str = str + "<xml>"
    str = str + "<expression>"
    str = str + Expression
    str = str + "</expression>"
    str = str + "</xml>"


    domSource.loadXML str
    str = "<?xml version='1.0' encoding='gb2312'?>" + vbCrLf
    str = str + "<xsl:stylesheet xmlns:xsl='http://www.w3.org/TR/WD-xsl'>"
    str = str + "<xsl:template match='/'>"
    str = str + "<Result>"
    str = str + "<xsl:eval language='vbscript'>Eval(me.text)</xsl:eval>"
    str = str + "</Result>"
    str = str + "</xsl:template>"
    str = str + "</xsl:stylesheet>"

    domStyleSheet.loadXML str


    domSource.transformNodeToObject domStyleSheet, domResult
    Test = domResult.Text
'    Test = True
    Exit Function
ErrorHandle:
    Test = False
End Function