TreeList.CustomDrawRowFooter Event

Provides the ability to perform custom painting of row footers.

Namespace: DevExpress.XtraTreeList

Assembly: DevExpress.XtraTreeList.v24.2.dll

Declaration

C#

[DXCategory("CustomDraw")]
public event CustomDrawRowFooterEventHandler CustomDrawRowFooter

VB.NET

<DXCategory("CustomDraw")>
Public Event CustomDrawRowFooter As CustomDrawRowFooterEventHandler

Event Data

The CustomDrawRowFooter event's data class is CustomDrawRowFooterEventArgs. The following properties provide information specific to this event:

Property	Description
Appearance	Gets the painted element’s appearance settings. Inherited from CustomDrawEventArgs.
Bounds	Gets the painted element’s bounding rectangle. Inherited from CustomDrawEventArgs.
Cache	Gets an object specifying the storage for the most used pens, fonts and brushes. Inherited from CustomDrawEventArgs.
FooterInfo	Gets an object containing information about the painted element.
Graphics	Gets an object used to paint. Inherited from CustomDrawEventArgs.
Handled	Gets or sets a value specifying whether an event was handled and that the default element painting is therefore not required. Inherited from CustomDrawEventArgs.
IsRightToLeft	Gets a value indicating whether the TreeList’s elements are aligned to support locales using right-to-left fonts. Inherited from CustomDrawEventArgs.
Node	Gets the node for whose children the painted row footer is displayed.
ObjectArgs	Gets an object containing information about the painted element. Inherited from CustomDrawEventArgs.
Painter	Gets the painter object that provides the default element’s painting mechanism. Inherited from CustomDrawEventArgs.

The event data class exposes the following methods:

Method	Description
DefaultDraw()	Performs default painting of an element. Inherited from CustomDrawEventArgs.
DrawHtml(HtmlTemplate, DxHtmlPainterContext, Action<DxHtmlPainterArgs>)	Paints the required HTML template inside an element that raised this event. The context parameter allows you to assign an object that transfers mouse events to template elements. Inherited from CustomDrawEventArgs.
DrawHtml(HtmlTemplate, Action<DxHtmlPainterArgs>)	Paints the required HTML template inside an element that raised this event. Inherited from CustomDrawEventArgs.

Remarks

Row footers are used to display row summaries, which are calculated over rows having the same parent. Handle the CustomDrawRowFooter event, to custom paint row footers. The event’s parameters provide you all the information needed for footer painting. Use the CustomDrawRowFooterEventArgs.Node parameter, to determine the parent of nodes for which the summary is being calculated.

You can perform custom painting of row footer cells by handling the TreeList.CustomDrawRowFooterCell event.

See the Custom Draw Scenarios topic for information on using custom draw events.

Important

Do not change cell values, modify the control’s layout, or change the control’s object model in the events used for custom control painting. Actions that update the layout can cause the control to malfunction.

Example

The following sample code handles the TreeList.CustomDrawRowFooter and TreeList.CustomDrawRowFooterCell events. These are used to perform custom painting of row footers and cells within it. Note that only cells containing values are painted.

C#

using System.Drawing;
using System.Drawing.Drawing2D;
using DevExpress.XtraTreeList;

private void treeList1_CustomDrawRowFooter(object sender, CustomDrawRowFooterEventArgs e) {
    // filling background with a linear gradient brush
    Brush backBrush = e.Cache.GetGradientBrush(e.Bounds, Color.Cornsilk,
      Color.LightSkyBlue, LinearGradientMode.Vertical);
    e.Cache.FillRectangle(backBrush, e.Bounds);
    // painting borders
    e.Cache.DrawRectangle(e.Cache.GetPen(Color.LightGray), e.Bounds);

    // prohibiting default painting
    e.Handled = true;
}

private void treeList1_CustomDrawRowFooterCell(object sender, 
CustomDrawRowFooterCellEventArgs e) {
    // cells which don't contain values are not painted
    if (e.Text == string.Empty) return;

    // filling background with a linear gradient brush
    Brush backBrush = e.Cache.GetGradientBrush(e.Bounds, Color.LightSkyBlue,
      Color.Cornsilk, LinearGradientMode.Vertical);
    e.Cache.FillRectangle(backBrush, e.Bounds);
    // painting borders
    e.Cache.DrawRectangle(e.Cache.GetPen(Color.LightGray), e.Bounds);
    // painting row footer cell value
    Rectangle textBounds = Rectangle.Inflate(e.Bounds, -4, 0);
    e.Cache.DrawString(e.Text, e.Appearance.Font, e.Cache.GetSolidBrush(Color.Black),
      textBounds, e.Appearance.GetStringFormat());

    // prohibiting default painting
    e.Handled = true;
}

VB.NET

Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports DevExpress.XtraTreeList

Private Sub TreeList1_CustomDrawRowFooter(ByVal sender As Object, _
ByVal e As CustomDrawRowFooterEventArgs) Handles TreeList1.CustomDrawRowFooter
    ' filling background with a linear gradient brush
    Dim BackBrush = e.Cache.GetGradientBrush(e.Bounds, Color.Cornsilk, Color.LightSkyBlue,
                                             LinearGradientMode.Vertical)
    e.Cache.FillRectangle(BackBrush, e.Bounds)
    ' painting borders
    e.Cache.DrawRectangle(e.Cache.GetPen(Color.LightGray), e.Bounds)

    ' prohibiting default painting
    e.Handled = True
End Sub

Private Sub TreeList1_CustomDrawRowFooterCell(ByVal sender As Object, _
ByVal e As CustomDrawRowFooterCellEventArgs) Handles TreeList1.CustomDrawRowFooterCell
    ' cells containing no text are not painted
    If e.Text = String.Empty Then Exit Sub
    ' filling cells background with a linear gradient brush
    Dim BackBrush = e.Cache.GetGradientBrush(e.Bounds, Color.LightSkyBlue,
                                             Color.Cornsilk, LinearGradientMode.Vertical)
    e.Cache.FillRectangle(BackBrush, e.Bounds)
    ' painting borders
    e.Cache.DrawRectangle(e.Cache.GetPen(Color.LightGray), e.Bounds)
    ' painting the footer cell value
    Dim textBounds As Rectangle = Rectangle.Inflate(e.Bounds, -4, 0)
    e.Cache.DrawString(e.Text, e.Appearance.Font, e.Cache.GetSolidBrush(Color.Blue),
                       textBounds, e.Appearance.GetStringFormat())
    ' prohibiting default painting
    e.Handled = True
End Sub