Question

I would like to ask for help regarding datasets and Crystal Reports.

I have two DataTables in the DataSet, namely the DeliveredItems and DeliveryDetails. The problem that I have encountered is in the DeliveredItems part, wherein I’ve got an error in the line at:

dataSet.Tables("DeliveredItems").Rows.Add(row)

which gives me:

"The row already belongs to this table."

And upon tweaking the code, it returned an error:

"Object reference not set to an instance of an object."

My objective is to get all the items of the ListView along with their subitems inside the dataset to be displayed on a Crystal Report. Here’s my code:

Private Sub CreateReport()

    'Initialize the needed objects for report document.
    Dim myDeliveryReport As New rptDeliveryReceipt
    Dim row As DataRow = Nothing
    Dim row2 As DataRow = Nothing
    Dim dataSet As New DataSet
    Dim counter As Integer = lviDeliveryList.Items.Count
    Dim tempCount As Integer = 0
    Dim listViewItems As New ListViewItem()

    'Create a new DataTable named Delivery Details
    dataSet.Tables.Add("DeliveryDetails")

    'Create columns for the new DataTable named Delivery Details.
    With dataSet.Tables(0).Columns

        .Add("deliveryClientName", Type.GetType("System.String"))
        .Add("deliveryClientStreetAddress", Type.GetType("System.String"))
        .Add("deliveryClientCity", Type.GetType("System.String"))
        .Add("deliveryDRNumber", Type.GetType("System.String"))
        .Add("deliveryDate", Type.GetType("System.String"))
        .Add("deliveryPONumber", Type.GetType("System.String"))

    End With

    'Initialize and insert delivery heading to the DataTable.
    row = dataSet.Tables(0).NewRow
    row(0) = txtDeliveryTargetClient.Text
    row(1) = txtDeliveryClientAddress.Text
    row(2) = txtDeliveryClientCity.Text
    row(3) = txtDRNumber.Text
    row(4) = dtpDeliveryDate.Value.ToString
    row(5) = txtDRPO.Text
    dataSet.Tables(0).Rows.Add(row)

    'Create another DataTable called DeliveredItems
    dataSet.Tables.Add("DeliveredItems")

    'Create columns for the new DataTable named DeliveryItems.
    With dataSet.Tables(1).Columns

        .Add("deliveryCatNumber", Type.GetType("System.String"))
        .Add("deliveryItemDescription", Type.GetType("System.String"))
        .Add("deliveryItemQuantity", Type.GetType("System.String"))
        .Add("deliveryItemUnit", Type.GetType("System.String"))
        .Add("deliveryItemDetails", Type.GetType("System.String"))

    End With

    row = Nothing
    row = dataSet.Tables(1).NewRow

    'Store every data in an array for insertion.
    Dim deliveredItemsCount As Integer = lviDeliveryList.Items.Count
    Dim tempArray() As String
    ReDim tempArray(5)
    Dim deliveryListViewItem As New ListViewItem()

    For counter = 0 To deliveredItemsCount

        deliveryListViewItem = lviDeliveryList.Items.Item(counter)
        tempArray(0) = lviDeliveryList.Items.Item(counter).ToString
        tempArray(1) = deliveryListViewItem.SubItems(1).ToString
        tempArray(2) = deliveryListViewItem.SubItems(2).ToString
        tempArray(3) = deliveryListViewItem.SubItems(3).ToString
        tempArray(4) = deliveryListViewItem.SubItems(4).ToString

        'Insert new records to the DeliveredItems.
        row2(0) = tempArray(0)
        row2(1) = tempArray(1)
        row2(2) = tempArray(2)
        row2(3) = tempArray(3)
        row2(4) = tempArray(4)
        dataSet.Tables("DeliveredItems").Rows.Add(row)

        For counterClear = 0 To (deliveredItemsCount - 1)
            tempArray(counter) = Nothing
        Next counterClear

        row2 = Nothing

    Next counter

    'Set Data Sources for the Crystal Report.
    myDeliveryReport.SetDataSource(dataSet)
    frmDeliveryReceiptReport.crvDeliveryReceipt.ReportSource = myDeliveryReport

    'Dispose after using.
    dataSet.Dispose()
    dataSet = Nothing

End Sub

Answer 1

In this line

 dataSet.Tables("DeliveredItems").Rows.Add(row) 

you are adding row not row2 and row2 is never initialized
I suppose you want to do:

For counter = 0 To deliveredItemsCount   

    deliveryListViewItem = lviDeliveryList.Items.Item(counter)   
    tempArray(0) = lviDeliveryList.Items.Item(counter).ToString   
    .....

    row2 = dataSet.Tables("DeliveredItems").NewRow
    row2(0) = tempArray(0)   
    ......
    dataSet.Tables("DeliveredItems").Rows.Add(row2)   

As a last note. I think you could avoid the tempArray… Set directly the values of row2 from the deliveryListViewItem. (remove also the array clearing at the end)