Question

I am trying to create a datatable in VB.NET, but when I output a row from this table it shows: “System.Data.DataRow”.

I have compared my code to several websites and it seems correct. However if I instead Response.Write these values they display correctly.

So here is my code:

        Sub Page_Load(Sender as Object, E as EventArgs)
            If Not IsPostback Then 
...
            End If

            Main
        End Sub

        Sub Main()
            Dim FirstMonthDate As Date = CDate("1/1/" & dYear.SelectedValue)
            Dim LastMonthDate As Date = GlobalFunctions.GlobalF.MonthLastDate(dYear.SelectedValue & "-" & dEndMonth.SelectedValue & "-1")
            Dim TheGroup As String
            Dim LastWeek As String
            Dim FirstWeek As String
            Dim dLastWeek As Date
            Dim dFirstWeek As Date
            Dim iWeek As String

            Dim commandstring As String = "SELECT cast(DateDiff(wk, '1/1/2011', '" & LastMonthDate & "') as varchar(30)) AS SELECTED_WEEK "
            Dim DSDateData As New System.Data.DataSet
            DSDateData = GlobalFunctions.GlobalF.GetDevSQLServerDataSet(commandstring)
            Dim dRow As DataRow

            For Each dRow In DSDateData.Tables(0).Rows
                iWeek = dRow("SELECTED_WEEK")
            Next

            Dim FirstYearDate As Date = CDate("1/1/" & dYear.SelectedValue)

            commandstring = "SELECT DateAdd(ww, " & iWeek & ", '" & FirstYearDate & "')  AS LAST_WEEK "
            Dim DSDateData2 As New System.Data.DataSet
            DSDateData2 = GlobalFunctions.GlobalF.GetDevSQLServerDataSet(commandstring)

            For Each dRow In DSDateData2.Tables(0).Rows
                LastWeek = dRow("LAST_WEEK")
            Next

            dLastWeek = CDate(LastWeek)

            commandstring = "SELECT DATEADD(dd, -1, DATEADD(wk, DATEDIFF(wk,0, dateadd(dd,6-datepart(day,'" & LastMonthDate & "'),'" & LastMonthDate & "') ), 0)) AS FIRST_WEEK "
            Dim DSDateData3 As New System.Data.DataSet
            DSDateData3 = GlobalFunctions.GlobalF.GetDevSQLServerDataSet(commandstring)

            For Each dRow In DSDateData3.Tables(0).Rows
                FirstWeek = dRow("FIRST_WEEK")
            Next

            dFirstWeek = CDate(FirstWeek)
            dFirstWeek = DateAdd(DateInterval.WeekOfYear, -1, dFirstWeek)

            Dim arrDayYear As New ArrayList()
            Dim dFirstDay As New Date

            Dim arrList As ArrayList = New ArrayList()

            Dim dt2 As New DataTable
            Dim sWeek As DataColumn = New DataColumn("sWeek")
            sWeek.DataType = System.Type.GetType("System.String")
            Dim sDay As DataColumn = New DataColumn("sDay")
            sDay.DataType = System.Type.GetType("System.String")
            dt2.Columns.Add(sWeek)
            dt2.Columns.Add(sDay)

Response.Write("NW1")

            Dim dr As DataRow
            dr = dt2.NewRow()
            dr("sWeek") = "New week"
            dr("sDay") = "New day"
            dt2.Rows.Add(dr)

            Response.Write(dr)
            Response.Write("<br>")

            dFirstDay = dFirstDay.AddDays(1)
...
End Sub
...

It’s this last Response.Write that is causing the “System.Data.DataRow”. But the Response.Write before this (NW1) does print. So what am I doing wrong?

Answer 1

Your code is correct.

Calling Response.Write(dr) prints dr.ToString().
Since DataRow doesn’t override ToString(), it jsut returns the typename.

You probably want to prin the value of a column.