求助，下面这个代码筛选结果出错 - 专家坐堂 - Foxtable(狐表) - 新一代数据库软件，完美融合Access、Foxpro、Excel、vb.net之优势，人人都能掌握的快速软件开发工具!

Dim Filter As String
Dim sts() As String = {"A列","B列","C列","D列"}
Dim tbl As Table = Tables("测试成绩表")
If e.Form.Controls("全部").Checked = True ' 如果状态选择了"全部"
    tbl.DataTable.loadFilter = ""
    tbl.DataTable.load
ElseIf e.Form.Controls("未测完").Checked = True ' 如果状态选择了"未测完"
    Dim str As String = "1=2"
    For Each st As String In sts
        str &= " or [" & st & "] Is Null"
    Next
    tbl.DataTable.loadFilter = str
    tbl.DataTable.load
ElseIf e.Form.Controls("免测").Checked = True ' 如果状态选择了"免测"
    tbl.DataTable.LoadFilter = "[备注] = '免测'"
    tbl.DataTable.load
End If

主题：求助，下面这个代码筛选结果出错