TreeList.PopulateColumns() Method

Creates columns for all public fields in the bound data source.

Namespace: DevExpress.XtraTreeList

Assembly: DevExpress.XtraTreeList.v23.2.dll

NuGet Packages: DevExpress.Win.Navigation, DevExpress.Win.TreeList

Declaration

C#

public virtual void PopulateColumns()

VB.NET

Public Overridable Sub PopulateColumns

Remarks

The TreeList automatically calls the PopulateColumns method once you bind it to a data source. This behavior is specified by the AutoPopulateColumns option. Disable this option and manually call the PopulateColumns method to create columns when needed.

The PopulateColumns method clears the TreeList’s Columns collection, creates columns for all public fields in a data source, and initializes column settings (FieldName, Caption, VisibleIndex ).

The PopulateColumns method has no effect in unbound mode.

Note

The PopulateColumns method does not create columns for service fields in the data source. Enable the TreeList’s PopulateServiceColumns option to create columns that are bound to Key, Parent, and Image fields specified by the KeyFieldName, ParentFieldName, and ImageIndexFieldName properties.

You can also create columns, customize their settings, and add them to the TreeList.Columns collection.

Example

The following example demonstrates how to create TreeList columns on button click.

C#

public partial class Form1 : DevExpress.XtraEditors.XtraForm {
    public Form1() {
        InitializeComponent();
        // Forces the Tree List to initialize its settings.
        treeList1.ForceInitialize();
        // Disables the 'AutoPopulateColumn' option.
        treeList1.OptionsBehavior.AutoPopulateColumns = false;
        // Configures the Tree List and binds it to data.
        treeList1.KeyFieldName = "ID";
        treeList1.ParentFieldName = "ParentID";
        treeList1.DataSource = NodeObject.InitNodes();
    }
    private void populateColsButton_Click(object sender, EventArgs e) {
        // Creates columns for all public fields in the bound data source.
        treeList1.PopulateColumns();
        // Expands all nodes.
        treeList1.ExpandAll();
    }
}

public class NodeObject {
    public int ID { get; set; }
    public int ParentID { get; set; }
    public string ValueA { get; set; }
    public string ValueB { get; set; }
    static public List<NodeObject> InitNodes() {
        return new List<NodeObject>() { 
            new NodeObject() { ID = 0,ParentID = 0, ValueA = "Value A-1", ValueB = "Value B-1" },
            new NodeObject() { ID = 1,ParentID = 0, ValueA = "Value A-1-0", ValueB = "Value B-1-0" },
            new NodeObject() { ID = 2,ParentID = 1, ValueA = "Value A-2-1", ValueB = "Value B-2-1" },
            new NodeObject() { ID = 3,ParentID = 2, ValueA = "Value A-3-2", ValueB = "Value B-3-2" },
            new NodeObject() { ID = 4,ParentID = 2, ValueA = "Value A-4-2", ValueB = "Value B-4-2" }
        };
    }
}

VB.NET

Partial Public Class Form1
    Inherits DevExpress.XtraEditors.XtraForm

    Public Sub New()
        InitializeComponent()
        ' Forces the Tree List to initialize its settings.
        treeList1.ForceInitialize()
        ' Disables the 'AutoPopulateColumn' option.
        treeList1.OptionsBehavior.AutoPopulateColumns = False
        ' Configures the Tree List and binds it to data.
        treeList1.KeyFieldName = "ID"
        treeList1.ParentFieldName = "ParentID"
        treeList1.DataSource = NodeObject.InitNodes()
    End Sub
    Private Sub populateColsButton_Click(ByVal sender As Object, ByVal e As EventArgs)
        ' Creates columns for all public fields in the bound data source.
        treeList1.PopulateColumns()
        ' Expands all nodes.
        treeList1.ExpandAll()
    End Sub
End Class

Public Class NodeObject
    Public Property ID() As Integer
    Public Property ParentID() As Integer
    Public Property ValueA() As String
    Public Property ValueB() As String
    Public Shared Function InitNodes() As List(Of NodeObject)
        Return New List(Of NodeObject)() From {
            New NodeObject() With {.ID = 0, .ParentID = 0, .ValueA = "Value A-1", .ValueB = "Value B-1"},
            New NodeObject() With {.ID = 1, .ParentID = 0, .ValueA = "Value A-1-0", .ValueB = "Value B-1-0"},
            New NodeObject() With {.ID = 2, .ParentID = 1, .ValueA = "Value A-2-1", .ValueB = "Value B-2-1"},
            New NodeObject() With {.ID = 3, .ParentID = 2, .ValueA = "Value A-3-2", .ValueB = "Value B-3-2"},
            New NodeObject() With {.ID = 4, .ParentID = 2, .ValueA = "Value A-4-2", .ValueB = "Value B-4-2"}
        }
    End Function
End Class

Related GitHub Examples

The following code snippets (auto-collected from DevExpress Examples) contain references to the PopulateColumns() method.

Note

The algorithm used to collect these code examples remains a work in progress. Accordingly, the links and snippets below may produce inaccurate results. If you encounter an issue with code examples below, please use the feedback form on this page to report the issue.

C#

winforms-dashboard-custom-items-extension/CS/CustomItemExtension/CustomItems/TreeList/TreeListItemControlProvider.cs#L88

tree.DataSource = flatData = customItemData.GetFlatData();
tree.PopulateColumns();
tree.ParentFieldName = dashboardItem.Metadata.ParentID.UniqueId;

winforms-treelist-expression-editor-xpview/CS/E1887/Form1.cs#L26

    xpView1.AddProperty(input.ColumnName, editor.Expression);
    treeList1.PopulateColumns();
}

VB.NET

winforms-dashboard-custom-items-extension/VB/CustomItemExtension/CustomItems/TreeList/TreeListItemControlProvider.vb#L99

tree.DataSource = flatData
tree.PopulateColumns()
tree.ParentFieldName = dashboardItem.Metadata.ParentID.UniqueId

winforms-treelist-expression-editor-xpview/VB/E1887/Form1.vb#L26

    xpView1.AddProperty(input.ColumnName, editor.Expression)
    treeList1.PopulateColumns()
End Using