主题：[求助]重复值、空值，怎样才能弹出警告窗

Dim fdr As DataRow = DataTables("表A").Find("计划单号 = '" & e.Sender.Text & "'")

If fdr IsNot Nothing Then

    msgbox("单号已存在")

    e.Cancel = True

End If

If e.Form.Controls("TextBox1").Text = Nothing Then

    msgbox("工程名称没填写")

    return

End If

If e.Form.Controls("TextBox2").Text = Nothing Then

    msgbox("计划编号没填写")

    return

End If

For Each r As Row In Tables("表A").rows
    For Each c As Col In Tables("表A").cols
        If r.IsNull(c.name) Then
            msgbox(r.index+1 & "行" & c.name & "列为空")
            Return
        End If
    Next
Next

Dim cs() As String = {"材料名称", "规格型号", "单位", "数量"}

For Each r As Row In Tables("表A").rows
    For Each c As String in cs
        If r.IsNull(c) Then
            msgbox(r.index+1 & "行" & c & "列为空")
            Return
        End If
    Next
Next

回复8楼，单号控件的 Validating 事件