Example E3371

Visible to All Users

WinForms Radio Group - Custom draw radio items

This example creates a custom radio group control that allows you to manually paint radio items:

C#
void OnCustomDrawItem(object sender, CustomDrawEventArgs e) {  
    if (e.ItemInfo.CheckState == CheckState.Checked) {  
        e.ItemInfo.Appearance.Font = new Font(e.ItemInfo.Appearance.Font, FontStyle.Bold | FontStyle.Underline);  
    }  
    if (e.ItemInfo.State == DevExpress.Utils.Drawing.ObjectState.Hot) {  
        LinearGradientBrush brush = new LinearGradientBrush(e.ItemInfo.Bounds, Color.LightBlue, Color.Cyan, LinearGradientMode.ForwardDiagonal);  
        e.Cache.FillRectangle(brush, e.ItemInfo.Bounds);  
        e.CheckPainter.DrawObject(e.ItemInfo);  

        e.Handled = true;  
    }  
}

Note

You can also use the following pre-designed and ready-to-use group controls shipped as part of DevExpress WinForms UI Templates:

- Chip Group
- Multi-Select Chip Group
- Radio Button Group
- Toggle Button Group

DevExpress WinForms UI Templates include predesigned and ready-to-use UI components and forms (C# and Visual Studio 2022 only).

Files to Review

CustomDrawEventArgs.cs (VB: CustomDrawEventArgs.vb)
CustomRadioGroup.cs (VB: CustomRadioGroup.vb)
CustomRadioGroupPainter.cs (VB: CustomRadioGroupPainter.vb)
Main.cs (VB: Main.vb)
Program.cs (VB: Program.vb)
RepositoryItemCustomRadioGroup.cs (VB: RepositoryItemCustomRadioGroup.vb)

Documentation

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Example Code

WindowsApplication3/CustomDrawEventArgs.cs(vb)

C#
VB.NET

C#
using System;
using System.Collections.Generic;
using System.Windows.Forms;
using DevExpress.Skins;
using DevExpress.Utils.Drawing;
using DevExpress.Utils;
using System.Drawing;
using DevExpress.XtraBars;
using DevExpress.XtraEditors.ViewInfo;

namespace WindowsApplication3 {
    public delegate void CustomDrawEventHandler(object sender, CustomDrawEventArgs e);
    public class CustomDrawEventArgs : EventArgs
    {
        GraphicsCache cache;
        RadioGroupItemViewInfo itemInfo;
        CheckObjectPainter checkPainter;
        bool handled;

        public CustomDrawEventArgs(GraphicsCache cache, RadioGroupItemViewInfo itemInfo, CheckObjectPainter checkPainter, bool handled)
        {
            this.cache = cache;
            this.itemInfo = itemInfo;
            this.checkPainter = checkPainter;
            this.handled = handled;
        }

        public GraphicsCache Cache
        {
            get { return cache; }
        }

        public RadioGroupItemViewInfo ItemInfo
        {
            get { return itemInfo; }
        }

        public CheckObjectPainter CheckPainter
        {
            get { return checkPainter; }
        }

        public bool Handled
        {
            get { return handled; }
            set
            {
                if (handled != value)
                    handled = value;
            }
        }
    }
}

Visual Basic
Imports System
Imports DevExpress.Utils.Drawing
Imports System.Drawing
Imports DevExpress.XtraEditors.ViewInfo

Namespace WindowsApplication3

    Public Delegate Sub CustomDrawEventHandler(ByVal sender As Object, ByVal e As CustomDrawEventArgs)

    Public Class CustomDrawEventArgs
        Inherits EventArgs

        Private cacheField As GraphicsCache

        Private itemInfoField As RadioGroupItemViewInfo

        Private checkPainterField As CheckObjectPainter

        Private handledField As Boolean

        Public Sub New(ByVal cache As GraphicsCache, ByVal itemInfo As RadioGroupItemViewInfo, ByVal checkPainter As CheckObjectPainter, ByVal handled As Boolean)
            cacheField = cache
            itemInfoField = itemInfo
            checkPainterField = checkPainter
            handledField = handled
        End Sub

        Public ReadOnly Property Cache As GraphicsCache
            Get
                Return cacheField
            End Get
        End Property

        Public ReadOnly Property ItemInfo As RadioGroupItemViewInfo
            Get
                Return itemInfoField
            End Get
        End Property

        Public ReadOnly Property CheckPainter As CheckObjectPainter
            Get
                Return checkPainterField
            End Get
        End Property

        Public Property Handled As Boolean
            Get
                Return handledField
            End Get

            Set(ByVal value As Boolean)
                If handledField <> value Then handledField = value
            End Set
        End Property
    End Class
End Namespace

WindowsApplication3/CustomRadioGroup.cs(vb)

C#
VB.NET

C#
using System;
using System.Collections.Generic;
using System.Windows.Forms;
using DevExpress.Skins;
using DevExpress.XtraEditors;
using System.ComponentModel;

namespace WindowsApplication3 {
    public class CustomRadioGroup : RadioGroup
    {

        static CustomRadioGroup() { RepositoryItemCustomRadioGroup.RegisterCustomEdit(); }

        public CustomRadioGroup() { }

        public override string EditorTypeName { get { return RepositoryItemCustomRadioGroup.CustomEditName; } }

        [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
        public new RepositoryItemCustomRadioGroup Properties
        {
            get { return base.Properties as RepositoryItemCustomRadioGroup; }
        }

    }

}

Visual Basic
Imports DevExpress.XtraEditors
Imports System.ComponentModel

Namespace WindowsApplication3

    Public Class CustomRadioGroup
        Inherits RadioGroup

        Shared Sub New()
            RepositoryItemCustomRadioGroup.RegisterCustomEdit()
        End Sub

        Public Sub New()
        End Sub

        Public Overrides ReadOnly Property EditorTypeName As String
            Get
                Return RepositoryItemCustomRadioGroup.CustomEditName
            End Get
        End Property

        <DesignerSerializationVisibility(DesignerSerializationVisibility.Content)>
        Public Overloads ReadOnly Property Properties As RepositoryItemCustomRadioGroup
            Get
                Return TryCast(MyBase.Properties, RepositoryItemCustomRadioGroup)
            End Get
        End Property
    End Class
End Namespace

WindowsApplication3/CustomRadioGroupPainter.cs(vb)

C#
VB.NET

C#
using System;
using System.Collections.Generic;
using System.Text;
using DevExpress.XtraEditors.Registrator;
using DevExpress.XtraEditors.Repository;
using System.Drawing;
using System.Reflection;
using DevExpress.XtraEditors.ViewInfo;
using DevExpress.XtraEditors.Drawing;
using DevExpress.XtraEditors;
using System.ComponentModel;
using System.Windows.Forms;
using WindowsApplication3;

namespace DXSample
{
    public class CustomRadioGroupPainter : RadioGroupPainter
    {
        public CustomRadioGroupPainter() : base() { }
        protected override void DrawRadioGroupItems(ControlGraphicsInfoArgs info)
        {
            RadioGroupViewInfo vi = info.ViewInfo as RadioGroupViewInfo;
            foreach (RadioGroupItemViewInfo itemInfo in vi.ItemsInfo)
            {
                itemInfo.Cache = info.Cache;
                try
                {
                    CustomDrawEventArgs e = new CustomDrawEventArgs(info.Cache, itemInfo, vi.RadioPainter, false);
                    RepositoryItemCustomRadioGroup item = vi.Item as RepositoryItemCustomRadioGroup;
                    item.RaiseCustomDrawItem(e);
                    if (!e.Handled)
                        vi.RadioPainter.DrawObject(itemInfo);
                    if (itemInfo.Focused)
                        ControlPaint.DrawFocusRectangle(info.Graphics, vi.GetFocusRect(itemInfo));
                }
                finally
                {
                  itemInfo.Cache = null;
                }
            }
        }
    }

}

Visual Basic
Imports System.Drawing
Imports DevExpress.XtraEditors.ViewInfo
Imports DevExpress.XtraEditors.Drawing
Imports System.ComponentModel
Imports System.Windows.Forms
Imports WindowsApplication3

Namespace DXSample

    Public Class CustomRadioGroupPainter
        Inherits RadioGroupPainter

        Public Sub New()
            MyBase.New()
        End Sub

        Protected Overrides Sub DrawRadioGroupItems(ByVal info As ControlGraphicsInfoArgs)
            Dim vi As RadioGroupViewInfo = TryCast(info.ViewInfo, RadioGroupViewInfo)
            For Each itemInfo As RadioGroupItemViewInfo In vi.ItemsInfo
                itemInfo.Cache = info.Cache
                Try
                    Dim e As CustomDrawEventArgs = New CustomDrawEventArgs(info.Cache, itemInfo, vi.RadioPainter, False)
                    Dim item As RepositoryItemCustomRadioGroup = TryCast(vi.Item, RepositoryItemCustomRadioGroup)
                    item.RaiseCustomDrawItem(e)
                    If Not e.Handled Then vi.RadioPainter.DrawObject(itemInfo)
                    If itemInfo.Focused Then ControlPaint.DrawFocusRectangle(info.Graphics, vi.GetFocusRect(itemInfo))
                Finally
                    itemInfo.Cache = Nothing
                End Try
            Next
        End Sub
    End Class
End Namespace

WindowsApplication3/Main.cs(vb)

C#
VB.NET

C#
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using DevExpress.XtraEditors;
using System.Drawing.Drawing2D;


namespace WindowsApplication3 {
    public partial class Main: XtraForm {
        public Main() {
            InitializeComponent();
        }
      
        private void OnCustomDrawItem(object sender, CustomDrawEventArgs e)
        {
            if (e.ItemInfo.CheckState == CheckState.Checked)
            {
                e.ItemInfo.Appearance.Font = new Font(e.ItemInfo.Appearance.Font, FontStyle.Bold | FontStyle.Underline);
            }
            if (e.ItemInfo.State == DevExpress.Utils.Drawing.ObjectState.Hot)
            {
                LinearGradientBrush brush = new LinearGradientBrush(e.ItemInfo.Bounds, Color.LightBlue, Color.Indigo, LinearGradientMode.ForwardDiagonal);
                e.Cache.FillRectangle(brush, e.ItemInfo.Bounds);
                e.CheckPainter.DrawObject(e.ItemInfo);
                
                e.Handled = true;
            }
        }
    }
}

Visual Basic
Imports System.ComponentModel
Imports System.Drawing
Imports System.Windows.Forms
Imports DevExpress.XtraEditors
Imports System.Drawing.Drawing2D

Namespace WindowsApplication3

    Public Partial Class Main
        Inherits XtraForm

        Public Sub New()
            InitializeComponent()
        End Sub

        Private Sub OnCustomDrawItem(ByVal sender As Object, ByVal e As CustomDrawEventArgs)
            If e.ItemInfo.CheckState = CheckState.Checked Then
                e.ItemInfo.Appearance.Font = New Font(e.ItemInfo.Appearance.Font, FontStyle.Bold Or FontStyle.Underline)
            End If

            If e.ItemInfo.State = DevExpress.Utils.Drawing.ObjectState.Hot Then
                Dim brush As LinearGradientBrush = New LinearGradientBrush(e.ItemInfo.Bounds, Color.LightBlue, Color.Indigo, LinearGradientMode.ForwardDiagonal)
                e.Cache.FillRectangle(brush, e.ItemInfo.Bounds)
                e.CheckPainter.DrawObject(e.ItemInfo)
                e.Handled = True
            End If
        End Sub
    End Class
End Namespace

WindowsApplication3/Program.cs(vb)

C#
VB.NET

C#
using System;
using System.Collections.Generic;
using System.Windows.Forms;
using DevExpress.Skins;

namespace WindowsApplication3 {
    static class Program {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        [STAThread]
        static void Main() {
            SkinManager.EnableFormSkins();
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            Application.Run(new Main());
        }
    }
}

Visual Basic
Imports System
Imports System.Windows.Forms
Imports DevExpress.Skins

Namespace WindowsApplication3

    Friend Module Program

        ''' <summary>
        ''' The main entry point for the application.
        ''' </summary>
        <STAThread>
        Sub Main()
            Call SkinManager.EnableFormSkins()
            Call Application.EnableVisualStyles()
            Application.SetCompatibleTextRenderingDefault(False)
            Call Application.Run(New Main())
        End Sub
    End Module
End Namespace

WindowsApplication3/RepositoryItemCustomRadioGroup.cs(vb)

C#
VB.NET

C#
using System;
using System.Collections.Generic;
using System.Windows.Forms;
using DevExpress.Skins;
using DevExpress.XtraEditors.Registrator;
using DevExpress.XtraEditors.Repository;
using System.Reflection;
using System.Drawing;
using DevExpress.XtraEditors.ViewInfo;
using DXSample;

namespace WindowsApplication3 {
    [UserRepositoryItem("RegisterCustomEdit")]
    public class RepositoryItemCustomRadioGroup : RepositoryItemRadioGroup
    {

        static RepositoryItemCustomRadioGroup() { RegisterCustomEdit(); }

        public RepositoryItemCustomRadioGroup() { }

        public const string CustomEditName = "CustomRadioGroup";

        public override string EditorTypeName { get { return CustomEditName; } }

        public static void RegisterCustomEdit()
        {
            Image img = null;
            try
            {
                img = (Bitmap)Bitmap.FromStream(Assembly.GetExecutingAssembly().
                  GetManifestResourceStream("DevExpress.CustomEditors.CustomEdit.bmp"));
            }
            catch
            {
            }
            EditorRegistrationInfo.Default.Editors.Add(new EditorClassInfo(CustomEditName,
              typeof(CustomRadioGroup), typeof(RepositoryItemCustomRadioGroup),
              typeof(RadioGroupViewInfo), new CustomRadioGroupPainter(), true, img));
        }

        static readonly object customDraw = new object();

        public event CustomDrawEventHandler CustomDrawItem
        {
            add { this.Events.AddHandler(customDraw, value); }
            remove { this.Events.RemoveHandler(customDraw, value); }
        }

        internal void RaiseCustomDrawItem(CustomDrawEventArgs e)
        {
            CustomDrawEventHandler handler = (CustomDrawEventHandler)Events[customDraw];
            if (handler != null) handler(GetEventSender(), e);
        }

        public override void Assign(RepositoryItem item)
        {
            BeginUpdate();
            try
            {
                base.Assign(item);
                RepositoryItemCustomRadioGroup source = item as RepositoryItemCustomRadioGroup;
                if (source == null) return;
                Events.AddHandler(customDraw, source.Events[customDraw]);
            }
            finally
            {
                EndUpdate();
            }
        }
    }

}

Visual Basic
Imports DevExpress.XtraEditors.Registrator
Imports DevExpress.XtraEditors.Repository
Imports System.Reflection
Imports System.Drawing
Imports DevExpress.XtraEditors.ViewInfo
Imports DXSample

Namespace WindowsApplication3

    <UserRepositoryItem("RegisterCustomEdit")>
    Public Class RepositoryItemCustomRadioGroup
        Inherits RepositoryItemRadioGroup

        Shared Sub New()
            Call RegisterCustomEdit()
        End Sub

        Public Sub New()
        End Sub

        Public Const CustomEditName As String = "CustomRadioGroup"

        Public Overrides ReadOnly Property EditorTypeName As String
            Get
                Return CustomEditName
            End Get
        End Property

        Public Shared Sub RegisterCustomEdit()
            Dim img As Image = Nothing
            Try
                img = CType(Bitmap.FromStream(Assembly.GetExecutingAssembly().GetManifestResourceStream("DevExpress.CustomEditors.CustomEdit.bmp")), Bitmap)
            Catch
            End Try

            Call EditorRegistrationInfo.Default.Editors.Add(New EditorClassInfo(CustomEditName, GetType(CustomRadioGroup), GetType(RepositoryItemCustomRadioGroup), GetType(RadioGroupViewInfo), New CustomRadioGroupPainter(), True, img))
        End Sub

        Private Shared ReadOnly customDraw As Object = New Object()

        Public Custom Event CustomDrawItem As CustomDrawEventHandler
            AddHandler(ByVal value As CustomDrawEventHandler)
                Events.AddHandler(customDraw, value)
            End AddHandler

            RemoveHandler(ByVal value As CustomDrawEventHandler)
                Events.RemoveHandler(customDraw, value)
            End RemoveHandler

            RaiseEvent(ByVal sender As Object, ByVal e As CustomDrawEventArgs)
            End RaiseEvent
        End Event

        Friend Sub RaiseCustomDrawItem(ByVal e As CustomDrawEventArgs)
            Dim handler As CustomDrawEventHandler = CType(Events(customDraw), CustomDrawEventHandler)
            If handler IsNot Nothing Then handler(GetEventSender(), e)
        End Sub

        Public Overrides Sub Assign(ByVal item As RepositoryItem)
            BeginUpdate()
            Try
                MyBase.Assign(item)
                Dim source As RepositoryItemCustomRadioGroup = TryCast(item, RepositoryItemCustomRadioGroup)
                If source Is Nothing Then Return
                Events.AddHandler(customDraw, source.Events(customDraw))
            Finally
                EndUpdate()
            End Try
        End Sub
    End Class
End Namespace

DevExpress Support Team

last modified 2 years ago

Modified: September 14, 2023 5:51 AM

Platform: WinForms

Product: XtraEditors Library

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WinForms Radio Group - Custom draw radio items

Files to Review

Documentation

Does this example address your development requirements/objectives?

Example Code

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