corelibraries-devexpress-dot-xtracharts-dot-customdrawserieseventargsbase-c42b3849.md
Gets or sets the image of the legend item marker of the series or series point that is currently being painted.
Namespace : DevExpress.XtraCharts
Assembly : DevExpress.XtraCharts.v25.2.dll
NuGet Package : DevExpress.Charts
public DXImage DXLegendMarkerImage { get; set; }
Public Property DXLegendMarkerImage As DXImage
| Type | Description |
|---|---|
| DXImage |
The image of the legend item marker.
|
Use this property instead of e.LegendMarkerImage to specify an image of the legend item marker.
This example demonstrates how to use the ChartControl.CustomDrawSeries event to modify the legend markers of bar series.
Assign a custom legend marker to the e.LegendMarkerImage property. Set the e.DisposeLegendMarkerImage property to true to avoid memory leaks. To customize options used to draw the series, cast e.SeriesDrawOptions to the DrawOptions class descendant that stores draw options of the required series view type.
using CustomDrawingSample.Model;
using DevExpress.Drawing;
using DevExpress.XtraCharts;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.IO;
using System.Linq;
namespace CustomDrawingSample {
public partial class Form1 : DevExpress.XtraEditors.XtraForm {
string trackedSeriesName;
Dictionary<string, DXImage> photoCache = new Dictionary<string, DXImage>();
#region #Constants
const int borderSize = 5;
const int scaledPhotoWidth = 48;
const int scaledPhotoHeight = 51;
// Width and height of scaled photo with border.
const int totalWidth = 58;
const int totalHeight = 61;
// Rects required to create a custom legend series marker.
static readonly Rectangle photoRect = new Rectangle(
borderSize, borderSize,
scaledPhotoWidth, scaledPhotoHeight);
static readonly Rectangle totalRect = new Rectangle(
0, 0,
totalWidth, totalHeight);
#endregion
public Form1() {
InitializeComponent();
}
private void Form1_Load(object sender, EventArgs e) {
using (var context = new NwindDbContext()) {
InitPhotoCache(context.Employees);
chart.DataSource = context.Orders.ToList();
}
chart.SeriesDataMember = "Employee.FullName";
chart.SeriesTemplate.ArgumentDataMember = "OrderDate";
chart.SeriesTemplate.ValueDataMembers.AddRange("Freight");
XYDiagram diagram = chart.Diagram as XYDiagram;
if (diagram != null) {
diagram.AxisX.DateTimeScaleOptions.AggregateFunction = AggregateFunction.Sum;
diagram.AxisX.DateTimeScaleOptions.MeasureUnit = DateTimeMeasureUnit.Year;
}
chart.CustomDrawSeries += OnCustomDrawSeries;
chart.ObjectHotTracked += OnObjectHotTracked;
}
private void OnObjectHotTracked(object sender, HotTrackEventArgs e) {
trackedSeriesName = e.HitInfo.InSeries ? ((Series)e.HitInfo.Series).Name : null;
}
void InitPhotoCache(IEnumerable<Employee> employees) {
photoCache.Clear();
foreach (var employee in employees) {
using (MemoryStream stream = new MemoryStream(employee.Photo)) {
if (!photoCache.ContainsKey(employee.FullName))
photoCache.Add(employee.FullName, DXImage.FromStream(stream));
}
}
}
#region #CustomDrawSeriesImplementation
private void OnCustomDrawSeries(object sender, CustomDrawSeriesEventArgs e) {
bool isSelected = e.Series.Name.Equals(trackedSeriesName);
// Design a series marker image.
DXBitmap image = new DXBitmap(totalWidth, totalHeight);
using (DXGraphics graphics = DXGraphics.FromImage(image)) {
using (var fillBrush = isSelected ? (DXBrush)new DXHatchBrush(DXHatchStyle.DarkDownwardDiagonal,
e.LegendDrawOptions.Color,
e.LegendDrawOptions.ActualColor2)
: (DXBrush)new DXSolidBrush(e.LegendDrawOptions.Color)) {
graphics.FillRectangle(fillBrush, totalRect);
}
DXImage photo;
if (photoCache.TryGetValue(e.Series.Name, out photo))
graphics.DrawImage(photo, photoRect);
}
e.DXLegendMarkerImage = image;
e.DisposeLegendMarkerImage = true;
BarDrawOptions options = e.SeriesDrawOptions as BarDrawOptions;
if (options != null && isSelected) {
options.FillStyle.FillMode = DevExpress.XtraCharts.FillMode.Hatch;
((HatchFillOptions)options.FillStyle.Options).HatchStyle = HatchStyle.DarkDownwardDiagonal;
}
}
#endregion
}
}
Imports CustomDrawingSample.Model
Imports DevExpress.Drawing
Imports DevExpress.XtraCharts
Imports System
Imports System.Collections.Generic
Imports System.Drawing
Imports System.Drawing.Drawing2D
Imports System.IO
Imports System.Linq
Namespace CustomDrawingSample
Public Partial Class Form1
Inherits DevExpress.XtraEditors.XtraForm
Private trackedSeriesName As String
Private photoCache As Dictionary(Of String, DXImage) = New Dictionary(Of String, DXImage)()
#Region "#Constants"
Const borderSize As Integer = 5
Const scaledPhotoWidth As Integer = 48
Const scaledPhotoHeight As Integer = 51
' Width and height of scaled photo with border.
Const totalWidth As Integer = 58
Const totalHeight As Integer = 61
' Rects required to create a custom legend series marker.
Private Shared ReadOnly photoRect As Rectangle = New Rectangle(borderSize, borderSize, scaledPhotoWidth, scaledPhotoHeight)
Private Shared ReadOnly totalRect As Rectangle = New Rectangle(0, 0, totalWidth, totalHeight)
#End Region
Public Sub New()
InitializeComponent()
End Sub
Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs)
Using context = New NwindDbContext()
InitPhotoCache(context.Employees)
chart.DataSource = context.Orders.ToList()
End Using
chart.SeriesDataMember = "Employee.FullName"
chart.SeriesTemplate.ArgumentDataMember = "OrderDate"
chart.SeriesTemplate.ValueDataMembers.AddRange("Freight")
Dim diagram As XYDiagram = TryCast(chart.Diagram, XYDiagram)
If diagram IsNot Nothing Then
diagram.AxisX.DateTimeScaleOptions.AggregateFunction = AggregateFunction.Sum
diagram.AxisX.DateTimeScaleOptions.MeasureUnit = DateTimeMeasureUnit.Year
End If
AddHandler chart.CustomDrawSeries, AddressOf OnCustomDrawSeries
AddHandler chart.ObjectHotTracked, AddressOf OnObjectHotTracked
End Sub
Private Sub OnObjectHotTracked(ByVal sender As Object, ByVal e As HotTrackEventArgs)
trackedSeriesName = If(e.HitInfo.InSeries, CType(e.HitInfo.Series, Series).Name, Nothing)
End Sub
Private Sub InitPhotoCache(ByVal employees As IEnumerable(Of Employee))
photoCache.Clear()
For Each employee In employees
Using stream As MemoryStream = New MemoryStream(employee.Photo)
If Not photoCache.ContainsKey(employee.FullName) Then photoCache.Add(employee.FullName, DXImage.FromStream(stream))
End Using
Next
End Sub
#Region "#CustomDrawSeriesImplementation"
Private Sub OnCustomDrawSeries(ByVal sender As Object, ByVal e As CustomDrawSeriesEventArgs)
Dim isSelected As Boolean = e.Series.Name.Equals(trackedSeriesName)
' Design a series marker image.
Dim image As DXBitmap = New DXBitmap(totalWidth, totalHeight)
Using graphics As DXGraphics = DXGraphics.FromImage(image)
Using fillBrush = If(isSelected, CType(New DXHatchBrush(DXHatchStyle.DarkDownwardDiagonal, e.LegendDrawOptions.Color, e.LegendDrawOptions.ActualColor2), DXBrush), CType(New DXSolidBrush(e.LegendDrawOptions.Color), DXBrush))
graphics.FillRectangle(fillBrush, totalRect)
End Using
Dim photo As DXImage
If photoCache.TryGetValue(e.Series.Name, photo) Then graphics.DrawImage(photo, photoRect)
End Using
e.DXLegendMarkerImage = image
e.DisposeLegendMarkerImage = True
Dim options As BarDrawOptions = TryCast(e.SeriesDrawOptions, BarDrawOptions)
If options IsNot Nothing AndAlso isSelected Then
options.FillStyle.FillMode = DevExpress.XtraCharts.FillMode.Hatch
CType(options.FillStyle.Options, HatchFillOptions).HatchStyle = HatchStyle.DarkDownwardDiagonal
End If
End Sub
#End Region
End Class
End Namespace
The following code snippets (auto-collected from DevExpress Examples) contain references to the DXLegendMarkerImage property.
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.
e.DisposeLegendMarkerImage = true;
e.DXLegendMarkerImage = bitmap;
}
e.DXLegendMarkerImage = image;
e.DisposeLegendMarkerImage = true;
winforms-chart-draw-a-custom-legend-marker-for-a-series/CS/CustomDrawingSample/Form1.cs#L87
}
e.DXLegendMarkerImage = image;
e.DisposeLegendMarkerImage = true;
e.DisposeLegendMarkerImage = True
e.DXLegendMarkerImage = bitmap
End Sub
e.DXLegendMarkerImage = image
e.DisposeLegendMarkerImage = True
winforms-chart-draw-a-custom-legend-marker-for-a-series/VB/CustomDrawingSample/Form1.vb#L88
e.DXLegendMarkerImage = image
e.DisposeLegendMarkerImage = True
See Also
CustomDrawSeriesEventArgsBase Class