主题：从字符串“夜班结束”到类型“Integer”的转换无效。

“从字符串“夜班结束”到类型“Integer”的转换无效。”这个我查不出来，请帮助

代码如下：

    If (t_now.now > t_daystart) And (t_now.now<t_nightoff) Then
        cmd.CommandText = "Select * From {考勤_夜班记录} Where [姓名] = '" & User.Name & "' and [日期] = '" & t.addDays(-1) & "'"
        dt = cmd.ExecuteReader
        If dt.DataRows.Count > 0 And dt.DataRows("夜班结束") IsNot Nothing Then
            e.Form.Controls("Label4").text = "您已下夜班打卡"
            e.Form.controls("Button_night").enabledd = False
            e.Form.controls("Button_nightoff").enabledd = False
        Else
            If dt.DataRows.count > 0 And dt.DataRows("夜班结束") Is Nothing Then
                e.Form.controls("Button_day").enabledd = False
                e.Form.controls("Button_dayoff").enabledd = False
                e.Form.controls("Button_night").enabledd = False
                e.Form.controls("Button_nightoff").enabledd = True
            Else
                e.Form.controls("Button_night").enabledd = False
                e.Form.controls("Button_nightoff").enabledd = False
               
            End If
        End If
       
    End If