How can I enumerate an ASP listview control? - html

Question

Below I take a list and convert it to a data table and bind it to an ASP listview control.
I'd like a function to convert it back to a List from an asp listview control and cannot figure out how to get the items? In Visual Studio debugging, the dataitems are null? It has the proper count but no values? I'd like to enumerate through all rows.
private void createLvwTable(List<string> table)
{
int index = 0;
DataTable dt = new DataTable();
foreach (string row in table)
{
string[] cells = row.Split('|');
if (index == 0) // header column
{
for (int j = 0; j < cells.Length; j++)
{
dt.Columns.Add(cells[j]);
//dt.Rows.Add();
}
}
else
{
DataRow dr = dt.NewRow();
for (int j = 0; j < cells.Length; j++)
{
dr[j] = cells[j];
}
dt.Rows.Add(dr);
}
index++;
}
lvwOutput.DataSource = dt;
lvwOutput.DataBind();
}

Answer 1

This is idiotic IMO so there is most likely a better way, but it appears you have to bind the data to an object during the listview creation. I couldn't find a good answer anywhere, this is a compilation of hours of searching and trying different combinations of semi-related answers.
On the html side you have to set the 'onitemdatabound' to a c# function. The code below also does not need to have the segmentation I'm going with a "|", I left that in to make it easier to read if you copy/paste my function.
I'd be happy to still read replies on how to do this better so I can learn.
html:
<asp:ListView ID="lvwOutput" runat="server" onitemdatabound="lvwOutput_ItemDataBound">
asp:
private List<string> lvwOutputItemsDataBoundToList = new List<string>();
private List<string> lvwOutputItemsDataBoundToListOriginal = new List<string>();
protected void lvwOutput_ItemDataBoundToList(object sender, ListViewItemEventArgs e)
{
if (e.Item.ItemType == ListViewItemType.DataItem)
{
ListViewDataItem dataItem = (ListViewDataItem)e.Item;
object o = (object)dataItem.DataItem;
System.Data.DataRowView rowView = e.Item.DataItem as System.Data.DataRowView;
object[] itemArray = rowView.Row.ItemArray;
string itemBound = "";
foreach(object item in itemArray)
{
itemBound += item.ToString() + "|";
}
if (itemBound.EndsWith("||"))
{
int index = itemBound.Length;
itemBound = itemBound.Remove(index - 2);
}
if (itemBound.EndsWith("|"))
{
int index = itemBound.Length;
itemBound = itemBound.Remove(index - 1);
}
lvwOutputItemsDataBoundToList.Add(itemBound);
}
ViewState["lvwOutputItemsDataBoundToList"] = lvwOutputItemsDataBoundToList;
}
private void filter()
{
lvwOutputItemsDataBoundToList = (List<string>)ViewState["lvwOutputItemsDataBoundToList"];
lvwOutputItemsDataBoundToListOriginal = lvwOutputItemsDataBoundToList;
foreach (string item in lvwOutputItemsDataBoundToList)
{
string[] itemSplit = item.Split('|');
}
}

Answer 2

To enumerate the ListViewItems see ListView.ListViewItemCollection Class and ListViewItem.SubItems Property.
List<string> lstItems = new List<string>():
foreach(ListViewItem itemRow in lvwOutput)
{
for (int i = 0; i < itemRow.SubItems.Count; i++)
{
lstItems.Add(itemRow.SubItems[i].Text);
}
}