NavBarControl.CustomDrawGroupCaption Event

Provides the ability to perform custom painting of group captions.

Namespace: DevExpress.XtraNavBar

Assembly: DevExpress.XtraNavBar.v18.2.dll

Declaration

C#

public event CustomDrawNavBarElementEventHandler CustomDrawGroupCaption

VB.NET

Public Event CustomDrawGroupCaption As CustomDrawNavBarElementEventHandler

Event Data

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

Property	Description
Appearance	Gets the painted element’s appearance settings. Inherited from CustomDrawObjectEventArgs.
Cache	Gets an object which specifies the storage for the most used pens, fonts and brushes. Inherited from CustomDrawObjectEventArgs.
Caption	Gets or sets the caption of the painted element.
Graphics	Gets an object used to paint the object. Inherited from CustomDrawObjectEventArgs.
Handled	Gets or sets a value specifying whether the control must perform default painting after an event handler has been executed. Inherited from CustomDrawObjectEventArgs.
Image	Gets or sets the image displayed within the painted element.
ObjectInfo	Gets an object providing information on the element being painted. Inherited from CustomDrawObjectEventArgs.
RealBounds	Gets the bounding rectangle of the painted object. Inherited from CustomDrawObjectEventArgs.

Remarks

Write a CustomDrawGroupCaption event handler to perform custom painting of group captions. Set the CustomDrawObjectEventArgs.Handled property of the event parameter to true to disable default painting. Other properties of the event parameter allow you to identify the group whose caption is painted and provide all necessary information to paint it.

Important

Never change cell values or modify the control’s layout on this event, or any other event designed to tune the control’s appearance. Any action that causes a layout update can cause the control to malfunction.

Example

The following sample code handles the NavBarControl.CustomDrawGroupCaption event to custom paint the borders around group captions, fill in the background and paint its text. The background is filled in, in various different ways depending upon the state of the group’s caption.

The image below shows the look & feel of group captions in the normal, hot tracked and pressed states, respectively.

C#

using System.Drawing.Drawing2D;
using DevExpress.Utils.Drawing;
using DevExpress.XtraNavBar.ViewInfo;

private void navBarControl1_CustomDrawGroupCaption(object sender, 
  CustomDrawNavBarElementEventArgs e) {
   // painting the borders
   Rectangle outerRect = e.RealBounds;
   SolidBrush outerBrush = new SolidBrush(Color.Orange);
   using(outerBrush) {
      e.Graphics.FillRectangle(outerBrush, outerRect);
   }

   // painting the background
   Rectangle innerRect = outerRect;
   innerRect.Inflate(-1, -1);
   LinearGradientBrush innerBrush;
   if (e.ObjectInfo.State == ObjectState.Hot)
      innerBrush = new LinearGradientBrush(innerRect, Color.PeachPuff, Color.Orange, 
        LinearGradientMode.Vertical);
   else if (e.ObjectInfo.State == ObjectState.Normal)
      innerBrush = new LinearGradientBrush(innerRect, Color.Orange, Color.PeachPuff, 
        LinearGradientMode.Horizontal);
   else
      innerBrush = new LinearGradientBrush(innerRect, Color.Orange, Color.PeachPuff, 
        LinearGradientMode.Vertical);
   using(innerBrush) {
      e.Graphics.FillRectangle(innerBrush, innerRect);
   }

   // painting the caption
   StringFormat outStringFormat = new StringFormat();
   outStringFormat.Alignment = StringAlignment.Near;
   outStringFormat.LineAlignment = StringAlignment.Center;
   SolidBrush textBrush = new SolidBrush(Color.White);
   NavGroupInfoArgs info = e.ObjectInfo as NavGroupInfoArgs;
   using(textBrush) {
      e.Graphics.DrawString(info.Group.Caption, e.Appearance.Font, textBrush, 
        innerRect, outStringFormat);
   }

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

VB.NET

Imports System.Drawing.Drawing2D
Imports DevExpress.Utils.Drawing
Imports DevExpress.XtraNavBar.ViewInfo

Private Sub NavBarControl1_CustomDrawGroupCaption(ByVal sender As Object, _
  ByVal e As CustomDrawNavBarElementEventArgs) Handles NavBarControl1.CustomDrawGroupCaption
   ' painting the borders
   Dim OuterRect As Rectangle = e.RealBounds
   Dim OuterBrush As New SolidBrush(Color.Orange)
   e.Graphics.FillRectangle(OuterBrush, OuterRect)
   OuterBrush.Dispose()

   ' painting the background
   Dim InnerRect As Rectangle = OuterRect
   InnerRect.Inflate(-1, -1)
   Dim InnerBrush As LinearGradientBrush
   If e.ObjectInfo.State = ObjectState.Hot Then
      InnerBrush = New LinearGradientBrush(InnerRect, Color.PeachPuff, Color.Orange, _
        LinearGradientMode.Vertical)
   ElseIf e.ObjectInfo.State = ObjectState.Normal Then
      InnerBrush = New LinearGradientBrush(InnerRect, Color.Orange, Color.PeachPuff, _
        LinearGradientMode.Horizontal)
   Else
      InnerBrush = New LinearGradientBrush(InnerRect, Color.Orange, Color.PeachPuff, _
        LinearGradientMode.Vertical)
   End If
   e.Graphics.FillRectangle(InnerBrush, InnerRect)
   InnerBrush.Dispose()

   ' painting the caption
   Dim TextRect As New RectangleF(InnerRect.Left, InnerRect.Top, InnerRect.Width, _
     InnerRect.Height)
   Dim TextBrush As New SolidBrush(Color.Blue)
   Dim OutStringFormat As New StringFormat()
   OutStringFormat.Alignment = StringAlignment.Near
   OutStringFormat.LineAlignment = StringAlignment.Center
   Dim info As NavGroupInfoArgs = e.ObjectInfo
   e.Graphics.DrawString(info.Group.Caption, e.Appearance.Font, TextBrush, TextRect, _
     OutStringFormat)
   TextBrush.Dispose()

   ' prohibiting default painting
   e.Handled = True
End Sub

Related GitHub Examples

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

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#

how-to-add-a-checkbox-to-the-navbar-groups-caption-e2061/CS/WindowsApplication1/NavBarGroupStateHelper.cs#L60

{
    NavBarControl.CustomDrawGroupCaption += NavBarControl_CustomDrawGroupCaption;
    NavBarControl.MouseClick += NavBarControl_MouseClick;

navbarcontrol-how-to-obtain-boundaries-of-elements-in-header-area-and-manually-paint-it-t497731/CS/NavBarCustomPaintHeader/Form1.cs#L15

    InitializeComponent();
    navBarControl1.CustomDrawGroupCaption += NavBarControl1_CustomDrawGroupCaption;
}

how-to-implement-the-quick-search-feature-for-the-navbarcontrol-e5220/CS/WindowsFormsApplication72/SearchHelper.cs#L44

_navBarControl.CustomDrawGroupCaption += navBarControl_CustomDrawGroupCaption;
textEdit.EditValueChanged += textEdit_EditValueChanged;

VB.NET

how-to-add-a-checkbox-to-the-navbar-groups-caption-e2061/VB/WindowsApplication1/NavBarGroupStateHelper.vb#L67

If navBarControl IsNot Nothing Then
    AddHandler Me.NavBarControl.CustomDrawGroupCaption, AddressOf NavBarControl_CustomDrawGroupCaption
    AddHandler Me.NavBarControl.MouseClick, AddressOf NavBarControl_MouseClick

navbarcontrol-how-to-obtain-boundaries-of-elements-in-header-area-and-manually-paint-it-t497731/VB/NavBarCustomPaintHeader/Form1.vb#L17

    InitializeComponent()
    AddHandler navBarControl1.CustomDrawGroupCaption, AddressOf NavBarControl1_CustomDrawGroupCaption
End Sub

how-to-implement-the-quick-search-feature-for-the-navbarcontrol-e5220/VB/WindowsFormsApplication72/SearchHelper.vb#L43

AddHandler _navBarControl.CustomDrawGroupCaption, AddressOf navBarControl_CustomDrawGroupCaption
AddHandler textEdit.EditValueChanged, AddressOf textEdit_EditValueChanged