TreeList.HyperlinkClick Event

Fires when a hyperlink in a column or band header is activated.

Namespace: DevExpress.XtraTreeList

Assembly: DevExpress.XtraTreeList.v23.2.dll

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

Declaration

C#

[DXCategory("Action")]
public event EventHandler<TreeListHyperlinkClickEventArgs> HyperlinkClick

VB.NET

<DXCategory("Action")>
Public Event HyperlinkClick As EventHandler(Of TreeListHyperlinkClickEventArgs)

Event Data

The HyperlinkClick event's data class is DevExpress.XtraTreeList.TreeListHyperlinkClickEventArgs.

Remarks

The TreeListOptionsView.AllowHtmlDrawHeaders property enables the use of HTML tags to format text in the following elements:

• Column headers (TreeListColumn.Caption).
• Band headers (TreeListBand.Caption).

You can use HTML tags to insert hyperlinks. The default behavior is to display hyperlinks, but restrict their activation on mouse events.

Set the TreeListOptionsBehavior.HyperlinkClickMode property to Click to allow users to activate hyperlinks on a mouse click. Set this property to CtrlClick to activate hyperlinks on a mouse click combined with the CTRL key.

Handle the HyperlinkClick event to perform actions when a hyperlink is activated.

Example

The following example displays a hyperlink in the header of the ‘Change’ Tree List column. The TreeList.HyperlinkClick event is handled to respond to a link click — which toggles the display mode of this column’s values.

C#

private void Form1_Load(object sender, EventArgs e) {
    BindingList<Ticker> list = new BindingList<Ticker>();
    list.Add(new Ticker() { Symbol = "AVR", Price = 101.4m, AbsoluteChange = 2.3m });
    list.Add(new Ticker() { Symbol = "RVA", Price = 414.1m, AbsoluteChange = 3.2m });
    list.Add(new Ticker() { Symbol = "ARBV", Price = 532.7m, AbsoluteChange = -18.0m });

    treeList1.DataSource = list;
    treeList1.OptionsView.AllowHtmlDrawHeaders = true;
    treeList1.OptionsBehavior.HyperlinkClickMode = DevExpress.Utils.Drawing.HyperlinkClickMode.CtrlClick;
    treeList1.HyperlinkClick += TreeList1_HyperlinkClick; ;

    treeList1.Columns["AbsoluteChange"].Visible = false;
    treeList1.Columns["PercentageChange"].Visible = false;

    TreeListColumn changeColumn = treeList1.Columns.AddVisible("Change");
    changeColumn.UnboundDataType = typeof(decimal);
    changeColumn.OptionsColumn.AllowEdit = false;
    updateChangeColumnDisplayMode();

    treeList1.Columns["Price"].Format.FormatType = DevExpress.Utils.FormatType.Numeric;
    treeList1.Columns["Price"].Format.FormatString = "c2";
}

bool usePercentageFormat = false;

private void TreeList1_HyperlinkClick(object sender, DevExpress.XtraTreeList.TreeListHyperlinkClickEventArgs e) {
    if (e.Link == "toggle-display-mode") {
        usePercentageFormat = !usePercentageFormat;
        updateChangeColumnDisplayMode();
    }
}

void updateChangeColumnDisplayMode() {
    TreeListColumn column = treeList1.Columns["Change"];
    if (column == null) return;
    column.Format.FormatType = DevExpress.Utils.FormatType.Numeric;
    if (usePercentageFormat) {
        column.Caption = "Change <a href=toggle-display-mode>(%)</a>";
        column.Format.FormatString = "p2";
        // Display values from the PercentageChange field.
        column.UnboundExpression = "PercentageChange";
    }
    else {
        column.Caption = "Change <a href=toggle-display-mode>($)</a>";
        column.Format.FormatString = "c2";
        // Display values from the AbsoluteChange field.
        column.UnboundExpression = "AbsoluteChange";
    }
}

public class Ticker {
    public string Symbol { get; set; }
    public decimal Price { get; set; }
    public decimal AbsoluteChange { get; set; }
    public decimal PercentageChange {
        get {
            if (Price > 0) return AbsoluteChange / Price;
            else return 0;
        }
    }
}

VB.NET

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
    Dim list As New BindingList(Of Ticker)()
    list.Add(New Ticker() With {
        .Symbol = "AVR",
        .Price = 101.4D,
        .AbsoluteChange = 2.3D
    })
    list.Add(New Ticker() With {
        .Symbol = "RVA",
        .Price = 414.1D,
        .AbsoluteChange = 3.2D
    })
    list.Add(New Ticker() With {
        .Symbol = "ARBV",
        .Price = 532.7D,
        .AbsoluteChange = -18D
    })

    TreeList1.DataSource = list
    TreeList1.OptionsView.AllowHtmlDrawHeaders = True
    TreeList1.OptionsBehavior.HyperlinkClickMode = DevExpress.Utils.Drawing.HyperlinkClickMode.CtrlClick
    AddHandler TreeList1.HyperlinkClick, AddressOf TreeList1_HyperlinkClick

    TreeList1.Columns("AbsoluteChange").Visible = False
    TreeList1.Columns("PercentageChange").Visible = False

    Dim changeColumn As TreeListColumn = TreeList1.Columns.AddVisible("Change")
    changeColumn.UnboundDataType = GetType(Decimal)
    changeColumn.OptionsColumn.AllowEdit = False
    updateChangeColumnDisplayMode()

    TreeList1.Columns("Price").Format.FormatType = DevExpress.Utils.FormatType.Numeric
    TreeList1.Columns("Price").Format.FormatString = "c2"
End Sub

Private usePercentageFormat As Boolean = False

Private Sub TreeList1_HyperlinkClick(sender As Object, e As TreeListHyperlinkClickEventArgs)
    If e.Link = "toggle-display-mode" Then
        usePercentageFormat = Not usePercentageFormat
        updateChangeColumnDisplayMode()
    End If
End Sub

Private Sub updateChangeColumnDisplayMode()
    Dim column As TreeListColumn = TreeList1.Columns("Change")
    If column Is Nothing Then
        Return
    End If
    column.Format.FormatType = DevExpress.Utils.FormatType.Numeric
    If usePercentageFormat Then
        column.Caption = "Change <a href=toggle-display-mode>(%)</a>"
        column.Format.FormatString = "p2"
        ' Display values from the PercentageChange field.
        column.UnboundExpression = "PercentageChange"
    Else
        column.Caption = "Change <a href=toggle-display-mode>($)</a>"
        column.Format.FormatString = "c2"
        ' Display values from the AbsoluteChange field.
        column.UnboundExpression = "AbsoluteChange"
    End If
End Sub

Public Class Ticker
    Public Property Symbol() As String
    Public Property Price() As Decimal
    Public Property AbsoluteChange() As Decimal
    Public ReadOnly Property PercentageChange() As Decimal
        Get
            If Price > 0 Then
                Return AbsoluteChange / Price
            Else
                Return 0
            End If
        End Get
    End Property
End Class