How to: Custom Paint the Group's Client Background

• Aug 01, 2019
• 2 minutes to read

The following sample code handles the NavBarControl.CustomDrawGroupClientBackground event to fill the top and bottom portions of a group’s client background with linear gradient brushes of opposing color.

The image below shows the result.

C#

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

private void navBarControl1_CustomDrawGroupClientBackground(object sender, 
  CustomDrawObjectEventArgs e) {
   // calculating the top and bottom part rectangles
   Rectangle rect = e.RealBounds;
   int halfHeight = rect.Height / 2;
   Rectangle topRect = new Rectangle(rect.Left, rect.Top, rect.Width, halfHeight);
   Rectangle bottomRect = new Rectangle(rect.Left, rect.Top + halfHeight, 
     rect.Width, halfHeight);

   // creating brushes for the top and bottom parts
   Color outerColor = Color.White;
   Color innerColor = Color.LightSkyBlue;
   LinearGradientBrush topBrush = new LinearGradientBrush(topRect, outerColor, innerColor,
     LinearGradientMode.Vertical);
   LinearGradientBrush bottomBrush = new LinearGradientBrush(bottomRect, innerColor, 
     outerColor, LinearGradientMode.Vertical);

   // filling the top and bottom rectangles with the created brushes
   e.Graphics.FillRectangle(topBrush, topRect);
   e.Graphics.FillRectangle(bottomBrush, bottomRect);

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

VB.NET

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

Private Sub NavBarControl1_CustomDrawGroupClientBackground(ByVal sender As Object, _
  ByVal e As CustomDrawObjectEventArgs) Handles NavBarControl1.CustomDrawGroupClientBackground
   ' calculating the top and bottom part rectangles
   Dim Rect As Rectangle = e.RealBounds
   Dim HalfHeight = Rect.Height / 2
   Dim TopRect As New Rectangle(Rect.Left, Rect.Top, Rect.Width, HalfHeight)
   Dim BottomRect As New Rectangle(Rect.Left, Rect.Top + HalfHeight, Rect.Width, HalfHeight)

   ' creating brushes for the top and bottom parts
   Dim OuterColor As Color = Color.White
   Dim InnerColor As Color = Color.LightSkyBlue
   Dim TopBrush As New LinearGradientBrush(TopRect, OuterColor, InnerColor, _
     LinearGradientMode.Vertical)
   Dim BottomBrush As New LinearGradientBrush(BottomRect, InnerColor, OuterColor, _
     LinearGradientMode.Vertical)

   ' filling the top and bottom rectangles with the created brushes
   e.Graphics.FillRectangle(TopBrush, TopRect)
   e.Graphics.FillRectangle(BottomBrush, BottomRect)

   ' prohibiting default painting     
   e.Handled = True
End Sub