Private WithEvents htmlDocument As htmlDocumentPrivate WithEvents btnCompute As MSHTML.HTMLButtonElementPrivate WithEvents txtNum1 As MSHTML.HTMLInputTextElementPrivate WithEvents txtNum2 As MSHTML.HTMLInputTextElementPrivate WithEvents txtResult As MSHTML.HTMLInputTextElementPrivate Function btnCompute_onclick() As Boolean    On Error GoTo ErrHandler:    txtResult.Value = CDbl(txtNum1.Value) + CDbl(txtNum2.Value)    Exit FunctionErrHandler:    MsgBox Err.DescriptionEnd FunctionPrivate Sub Command1_Click()    Text1.Visible = Not Text1.VisibleEnd SubPrivate Sub Form_Load()    WebBrowser1.Navigate "about:blank"    Do While WebBrowser1.Busy Or WebBrowser1.ReadyState <> READYSTATE_COMPLETE        DoEvents    Loop    WebBrowser1.Document.write Text1.Text    Do While WebBrowser1.Busy Or WebBrowser1.ReadyState <> READYSTATE_COMPLETE        DoEvents    Loop        Set htmlDocument = WebBrowser1.Document    Set btnCompute = htmlDocument.getElementById("btnCompute")    Set txtNum1 = htmlDocument.getElementById("txtNum1")    Set txtNum2 = htmlDocument.getElementById("txtNum2")    Set txtResult = htmlDocument.getElementById("txtResult")End SubPrivate Function htmlDocument_onclick() As Boolean    Debug.Print "触发了元素" & htmlDocument.parentWindow.event.srcElement.id & "的" & htmlDocument.parentWindow.event.Type & "事件"End Function