主题：Cannot perform '=' operation on System.Int32 and System.String.涵义

我也遇到这个问题了

Dim lb As WinForm.ComboBox = e.Form.Controls("类别")
Dim sycl As WinForm.ComboBox = e.Form.Controls("使用策略")
Dim ggxx As WinForm.TextBox = e.Form.Controls("规格")'规格下限
Dim ggsx As WinForm.TextBox = e.Form.Controls("上限") '规格上限
Dim gz As WinForm.RadioButton = e.Form.Controls("公制")
Dim yz  As WinForm.RadioButton = e.Form.Controls("英制")
Dim gg As Single
Dim FilterA As String
Dim syclv As String
If ggxx.Text="下限" Then ggxx.text=Nothing
If ggsx.Text="上限" Then ggsx.text=Nothing
Dim lbv As String

If lb.text="" Then
    lbv="*"
    filterA="TCatg Like '*'"
Else
    lbv=lb.Text
    filtera="TCatg like '" &  lb.text & "'"
End If
If gz.Checked Then
    filtera=filtera & " and MMIN =true"
ElseIf yz.Checked Then
    filtera=filtera & "And MMIN=false"
End If
If sycl.text<>"全部" Then
    If sycl.Text <>"" Then
        filtera=filtera & " and RMLC ='"  & sycl.Text & "'"
    End If
End If

If IsNumeric(ggxx.value) Then   '规格下限为数值型
    MessageBox.Show("暂停1:  " & ggxx.value & ":" & ggsx.Value)
    If ggxx.value>=0 Then
        If  ggsx.value>0 Then
            MessageBox.Show("暂停2")
            If ggxx.value>ggsx.value Then
                MessageBox.Show("暂停3")
                gg=ggxx.value
                ggxx.value=ggsx.value  '重置上下限
                ggsx.value=gg
            End If
            Dim xx As Single=ggxx.value
            Dim sx As Single=ggsx.value
            filtera=filtera & " and [NorDiameter] >=" & xx & " And  [NorDiameter] <= " & sx
            MessageBox.Show("暂停5")
        ElseIf ggsx.value Is Nothing Then
Dim xx As Single = ggxx.value
            MessageBox.Show("暂停4")
            filtera=filtera & " and NorDiameter=" & xx
        End If
    End If
ElseIf ggxx.text  Is Nothing Then  '字符型,如丝锥等
    MessageBox.Show("暂停6B")
    filtera=filtera & " and NorDiameter like '*" & ggxx.Text & "*'"
End If
MessageBox.Show("暂停7" & FilterA)
DataTables("ToolingTechList").AllowEdit=True
Tables("ToolingTechList").Filter=filterA

执行到filter时出现