NavBarControl.CustomDrawBackground Event

Provides the capability to custom paint the control’s background.

Namespace: DevExpress.XtraNavBar

Assembly: DevExpress.XtraNavBar.v18.1.dll

Declaration

C#

public event CustomDrawObjectEventHandler CustomDrawBackground

VB.NET

Public Event CustomDrawBackground As CustomDrawObjectEventHandler

Event Data

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

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

Remarks

Write a CustomDrawBackground event handler to perform custom painting of the control’s background. Set the CustomDrawObjectEventArgs.Handled property of the event parameter to true to disable default background painting. Other event parameters provide you with all the necessary information to perform background painting.

Group captions and client areas occupy the entire control’s area in certain paint styles. Writing a CustomDrawBackground event has no impact in such a case.

Note

The control’s events designed to change the appearance or rendering of control elements must not be used to update cell values or to modify the control’s layout. Any inappropriate operation which causes a layout update, may break the normal control behavior.

Example

The following sample code handles the NavBarControl.CustomDrawBackground event to fill the XtraNavBarControl’s background with a linear gradient brush and draw a string at the bottom.

The image below shows the result.

C#

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

private void navBarControl1_CustomDrawBackground(object sender, CustomDrawObjectEventArgs e) {

   Rectangle rect = e.RealBounds;
   Graphics gr = e.ObjectInfo.Graphics;

   // creating a brush and filling the background with it
   LinearGradientBrush backBrush = new LinearGradientBrush(rect, Color.Pink, 
     Color.LightSkyBlue, LinearGradientMode.Horizontal);
   gr.FillRectangle(backBrush, rect);

   // creating a new font for the string
   Font stringFont = new Font("Verdana", 8);
   // creating a brush used to draw the string
   LinearGradientBrush stringBrush = new LinearGradientBrush(rect, Color.Blue, 
     Color.Red, LinearGradientMode.Horizontal);
   // calculating string rectangle 
   int stringHeight = Convert.ToInt16(gr.MeasureString("www.devexpress.com", 
     stringFont).Height);
   Rectangle stringRect = new Rectangle(rect.Left, rect.Bottom - stringHeight, 
     rect.Width, stringHeight);
   // formatting string output
   StringFormat outStringFormat = new StringFormat();
   outStringFormat.Alignment = StringAlignment.Center;

   // drawing the string
   gr.DrawString("www.devexpress.com", stringFont, stringBrush, stringRect, outStringFormat);

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

VB.NET

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

Private Sub NavBarControl1_CustomDrawBackground(ByVal sender As Object, _
  ByVal e As CustomDrawObjectEventArgs) Handles NavBarControl1.CustomDrawBackground

   Dim Rect As Rectangle = e.RealBounds
   Dim Gr As Graphics = e.ObjectInfo.Graphics

   ' creating a brush and filling the background with it
   Dim BackBrush As New LinearGradientBrush(Rect, Color.Pink, Color.LightSkyBlue, _
     LinearGradientMode.Horizontal)
   Gr.FillRectangle(BackBrush, Rect)

   ' creating a new font for the string
   Dim StringFont As New Font("Verdana", 8)
   ' creating a brush used to draw the string
   Dim StringBrush As New LinearGradientBrush(Rect, Color.Blue, Color.Red, _
     LinearGradientMode.Horizontal)
   ' calculating string rectangle 
   Dim StringHeight = Gr.MeasureString("www.devexpress.com", StringFont).Height
   Dim StringRect As New RectangleF(Rect.Left, Rect.Bottom - StringHeight, Rect.Width, _
     StringHeight)
   ' formatting string output
   Dim OutStringFormat As New StringFormat()
   OutStringFormat.Alignment = StringAlignment.Center

   ' drawing the string
   Gr.DrawString("www.devexpress.com", StringFont, StringBrush, StringRect, OutStringFormat)

   ' prohibiting default background painting
   e.Handled = True
End Sub