这个代码出了什么问题

[po4920826]

已经添加了microsoft html object的引用(com)

Public Shared Function GetRegCodePic(ByVal wbMail As WebBrowser, ByVal ImgName As String) As Image

        Dim doc As HtmlDocument = DirectCast(wbMail.Document.DomDocument, HtmlDocument)
        Dim body As MSHTML.HTMLBody = DirectCast(doc.Body, MSHTML.HTMLBody)
        Dim rang As MSHTML.IHTMLControlRange = DirectCast(body.createControlRange(), MSHTML.IHTMLControlRange)
        Dim Img As MSHTML.IHTMLControlElement
        Img = DirectCast(wbMail.Document.All(ImgName).DomElement, MSHTML.IHTMLControlElement)

        rang.add(Img)
        rang.execCommand("Copy ", False, Nothing)
        Dim RegImg As Image = Clipboard.GetImage()
        'Clipboard.Clear()
        Return RegImg

    End Function

----------------------------------------
当执行到
DirectCast(doc.Body, MSHTML.HTMLBody)
提示无法转换

这个代码是截取网页验证码的

[po4920826]

早添加过了

[只在此山中]

添加引用Microsoft.mshtml

[mzhao]

doc.Body是.Net实例（其实也在做封装类的工作，但在Windows.Forms.dll中有.Net实际代码），
MSHTML.HTMLBody是COM封装类，无法直接转换。

要么从头就用MSHTML的控件，要么不要用MSHTML。

[po4920826]

重装了系统和.net3.5还有vb2008
错误没了

我怀疑是我的.net版本混乱造成的