Hi,

I wonder if there is a way to group a TreeList by more than one column, but at the same level. If I have something like:

Name	Surname	Model of car
John	Braun	Audi A6
John	Braun	Mercedes SLK
Thomas	Silvester	Wolkswagen Passat 2.0
Monica	Dufreau	Ford Fiesta

I want to get to something like this (group by name and surname at the same level):

John	Braun
		Audi A6
		Mercedes SLK
Thomas	Silvester
		Wolkswagen Passat 2.0
Monica	Dufreau
		For Fiesta

Two more questions:

• is there a way to get the columns used in groupby and their order?
• is there a way to modify the list of columns that appear in the context menu of the grid (right click on a column header -> Choose columns)?

Thanks,

IM

Hi Ignacio,

You cannot do this with default state of the control.

However, if you are binding your data to NTreeList control you can subclass NTreeListTableData in order to build the nodes and subitems of NTreeList to look like you described.

I made an example which is doing that, but the source is strongly tided with the data structure and if the data structure changes it may not work correctly.

First lets create a DataTable with your data:

private DataTable LoadTable()
{
    DataTable table = new DataTable();
    DataColumn column1 = new DataColumn("Name");
    DataColumn column2 = new DataColumn("SurName");
    DataColumn column3 = new DataColumn("Car");
    table.Columns.AddRange(new DataColumn[] { column1, column2, column3 });

    DataRow row0 = table.NewRow();
    row0[0] = "John";
    row0[1] = "Braun";
    row0[2] = "Audi A6";
    table.Rows.Add(row0);

    DataRow row1 = table.NewRow();
    row1[0] = "John";
    row1[1] = "Braun";
    row1[2] = "Mercedes SLK";
    table.Rows.Add(row1);

    DataRow row2 = table.NewRow();
    row2[0] = "Thomas";
    row2[1] = "Silvester";
    row2[2] = "Volkswagen Passat 2.0";
    table.Rows.Add(row2);

    DataRow row3 = table.NewRow();
    row3[0] = "Monica";
    row3[1] = "Dufreau";
    row3[2] = "Ford Fiesta";
    table.Rows.Add(row3);

    table.DefaultView.Sort = "Name, SurName DESC";

    return table;
}

Then create new class that derives from NTreeListTableData and override PopulateRows method:

public class MyNTreeListData : NTreeListTableData
{
    protected override void PopulateRows()
    {
        DataView view = Table.DefaultView;
        int count = view.Count;
        DataRowView row;
        DataRowView temp = null;
        NTreeListNode tempNode = null;

        for (int i = 0; i < count; i++)
        {
            row = view[i];
            string row2 = string.Empty;
            if (i == 0)
            {
                tempNode = GetRow(row.Row);
                row2 = row.Row[2].ToString();
                AddSubNode(row2, tempNode);
                temp = row;
                continue;
            }

            if (row.Row[0] != temp.Row[0] || row.Row[1] != temp.Row[1])
            {
                Owner.Nodes.Add(tempNode);
                tempNode = GetRow(row.Row);
            }
            else
            {
                row2 = row.Row[2].ToString();
                AddSubNode(row2, tempNode);
                temp = row;
                continue;
            }

            row2 = row.Row[2].ToString();
            AddSubNode(row2, tempNode);
            temp = row;
        }

        Owner.Nodes.Add(tempNode);
    }

    protected void AddSubNode(string nodeText, NTreeListNode node)
    {
        NTreeListNode subNode = new NTreeListNode();
        NTreeListNodeStringSubItem subitem = new NTreeListNodeStringSubItem(nodeText);
        subitem.Column = Owner.Columns[2];
        subNode.SubItems.Add(subitem);
        node.Nodes.Add(subNode);
    }

    protected NTreeListNode GetRow(DataRow row)
    {
        NTreeListNode node = new NTreeListNode();
        object[] values = row.ItemArray;
        object value;
        int length = values.Length;
        NTreeListNodeSubItem item;

        for (int i = 0; i < length - 1; i++)
        {
            value = values[i];
            item = CreateSubItem(value);
            item.Column = Owner.Columns[i];
            node.SubItems.Add(item);
        }

        return node;
    }
}

Finally, all you need is to bind NTreeList to the data using the new class:

MyNTreeListData data = new MyNTreeListData();
data.Table = LoadTable();
data.Bind(nTreeList1);

Ones again I want to mension that this example implementation applies only for specific structure of your data.

I hope this helps.

 

Best Regards,
Nevron Support Team

Hi,

And regarding the list of columns displayed in the Choose columns option, and the list of columns (and order) used when grouping, is there a way to get them?

Thanks and regards,

 

IM

Hi Ignacio,

In both cases you can get the columns from Columns property. The order of the displayed columns is the same as it is in Columns collection.
If there is a grouping usually group by column is hidden. However this column still exist in Columns collection, but its IsVisible property is false.

Best Regards,
Nevron Support Team