正在将ListView的内容插入数据集

Question

我想寻求有关数据集和Crystal Reports的帮助。

我在数据集中有两个数据表，即DeliveredItems和DeliveryDetails。我遇到的问题是在DeliveredItems部分，其中我在的行中遇到了一个错误

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

这给了我：

"The row already belongs to this table."

在调整代码后，它返回了一个错误：

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

我的目标是让ListView的所有项及其子项在数据集中显示在Crystal Report上。这是我的代码：

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

在行中

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

您添加的行不是row2，并且row2从未初始化我想你想做：

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)   

最后一点。我想你可以避开tempArray。。。从deliveryListViewItem直接设置row2的值。（也删除最后的数组清除）