Obtaining and Setting Cell Values

• Oct 29, 2020
• 3 minutes to read

The Tree List control displays data by means of nodes that contain cells for each column. Each cell’s data can be obtained and changed. See below, for information on how to get and set cell values.

 

API

To get and set cell values in code, use the methods provided by the TreeList and TreeListNode classes:

Member	Description
TreeList.SetRowCellValue	Sets the TreeList cell to a specific value.
TreeListNode.Item	Gets or sets the edit value of a specific cell.
TreeListNode.GetValue	Returns the edit value of a specific cell.
TreeListNode.GetDisplayText	Returns the display value of a specific cell. Display values are text representations of edit values, formatted in a specific manner.
TreeListNode.SetValue	Changes the edit value of a specific cell.

There are multiple ways to obtain a node object before getting/changing its cells. Please refer to Member Table: Nodes, to find out which common methods can be used to obtain references to nodes.

The methods listed in the table above require a column identifier as a parameter. The following section describes column identifiers supported by the methods.

Column Identifiers

Several objects can be used as column identifiers. These are:

• The TreeListColumn object representing the desired column.

  The following code may be used to obtain a TreeListColumn object by its field name. We will assume that there is a column bound to the “Budget” field. The TreeList.Columns property of the Tree List control is used to access the column.

  C#

  TreeListColumn columnID1 = treeList1.Columns["Budget"];
  // Get a cell's value in the first root node.
  object cellValue1 = treeList1.Nodes[0][columnID1];
  

  VB.NET

  Dim columnID1 As TreeListColumn = TreeList1.Columns("Budget")
  ' Get a cell's value in the first root node.
  Dim cellValue1 As Object = TreeList1.Nodes(0)(columnID1)
  

• The TreeListColumn.FieldName property value of the desired column.

  The field name is a string that binds the column to a data source field. When a Tree List is populated from the System.Data.DataTable object, for example, the TreeListColumn.FieldName is automatically initialized with the name of a field from the data source.

  C#

  string columnID2 = "Budget";
  // Get the display text of the focused node's cell
  string cellText = treeList1.FocusedNode.GetDisplayText(columnID2);
  

  VB.NET

  Dim columnID2 As String  = "Budget"
  ' Get the display text of the focused node's cell.
  Dim cellText As String = TreeList1.FocusedNode.GetDisplayText(columnID2)
  

• The TreeListColumn.AbsoluteIndex property value of the desired column.

  The absolute index is the position of the column within the column collection. The following code demonstrates how to get this value for the “Budget” column.

  C#

  int columnID3 = treeList1.Columns["Budget"].AbsoluteIndex;
  // Get a cell's value in the first root node.
  object cellValue = treeList1.Nodes[0].GetValue(columnID3);
  

  VB.NET

  Dim columnID3 As Integer= TreeList1.Columns("Budget").AbsoluteIndex
  ' Get a cell's value in the first root node.
  Dim cellValue As Object = TreeList1.Nodes(0).GetValue(columnID3)
  

• The System.Data.DataColumn object corresponding to the desired column (if the TreeList.DataSource is represented by a System.Data.DataView or System.Data.DataTable source).

  C#

  DataColumn columnID4 = dataView.Table.Columns["DB_FieldName"];
  // Set a cell's value.
  object newCellValue;
  treeList1.Nodes[0].SetValue(columnID4, newCellValue);
  

  VB.NET

  DataColumn columnID4 = dataView.Table.Columns("DB_FieldName");
  ' Set a cell's value.
  Dim newCellValue As Object
  TreeList1.Nodes(0).SetValue(columnID4, newCellValue)
  

Task-Based Help

• How to: Change values in a specific column for root nodes

Member Tables

• Member Table: Obtain and Set Cell Values