BaseListBoxControl.DrawItem Event

Provides the ability to custom paint items displayed within the list box control.

Namespace: DevExpress.XtraEditors

Assembly: DevExpress.XtraEditors.v18.2.dll

Declaration

C#

[DXCategory("Behavior")]
public event ListBoxDrawItemEventHandler DrawItem

VB.NET

<DXCategory("Behavior")>
Public Event DrawItem As ListBoxDrawItemEventHandler

Event Data

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

Property	Description
AllowDrawSkinBackground	Gets or sets whether the item background is colored according to the currently applied skin.
Appearance	Gets the appearance settings used to paint the item currently being processed.
Bounds	Gets the bounding rectangle of the item being painted.
Cache	Gets an object which specifies the storage for the most used pens, fonts and brushes.
Graphics	Gets an object used to paint an item.
Handled	Gets or sets a value specifying whether default painting is required.
Index	Gets the index of the item being painted.
Item	Gets the value of the processed item.
State	Gets the state of the item being painted.

The event data class exposes the following methods:

Method	Description
DefaultDraw()	Performs default painting of an element.
GetItemInfo()	This member supports the internal infrastructure, and is not intended to be used directly from your code.

Remarks

The list box control enables you to custom paint its items. Handle the DrawItem event to override default item painting. This event is raised each time an item is about to be painted. The event parameter’s properties allow you to define the object used to paint, the item’s boundaries, style and the index of the item. To get the item’s state (selected, checked, grayed, inactive, etc) and the value of the item being drawn, use the ListBoxDrawItemEventArgs.State and ListBoxDrawItemEventArgs.Item properties respectively.

Note: you must set the ListBoxDrawItemEventArgs.Handled property to true to override the default painting.

Example

The following sample code handles the BaseListBoxControl.DrawItem event to custom paint the items displayed within the ListBoxControl. The odd and even items are painted with different appearance settings. A specific painting is applied to the currently selected item.

The image below shows the result.

C#

using DevExpress.XtraEditors;

private void listBoxControl1_DrawItem(object sender, ListBoxDrawItemEventArgs e) {
   Brush backBrush1 = new SolidBrush(Color.FromArgb(224, 251, 254));
   Brush backBrush2 = new SolidBrush(Color.FromArgb(198, 241, 249));
   Brush backBrush3 = new SolidBrush(Color.FromArgb(253, 192, 47));
   // declare field representing the text of the item being drawn
   string itemText = (sender as ListBoxControl).GetItemText(e.Index);
   if ((e.State & DrawItemState.Selected) != 0){
      e.Cache.FillRectangle(backBrush3, e.Bounds);
      ControlPaint.DrawBorder3D(e.Graphics, e.Bounds);
      e.Cache.DrawString(itemText, new Font(e.Appearance.Font.Name, 
        e.Appearance.Font.Size, FontStyle.Bold), new SolidBrush(Color.Black), 
        e.Bounds, e.Appearance.GetStringFormat());
      e.Handled = true;
      return;
   }
   if(e.Index % 2 == 0){
      e.Cache.FillRectangle(backBrush1, e.Bounds);
   }
   else{
      e.Cache.FillRectangle(backBrush2, e.Bounds);
   }
   e.Cache.DrawString(itemText, e.Appearance.Font, new SolidBrush(Color.Black), 
     e.Bounds, e.Appearance.GetStringFormat());
   e.Handled = true;
}

VB.NET

Private Sub ListBoxControl1_DrawItem(ByVal sender As Object, _
  ByVal e As DevExpress.XtraEditors.ListBoxDrawItemEventArgs) _
  Handles ListBoxControl1.DrawItem
   Dim backBrush1 As New SolidBrush(Color.FromArgb(224, 251, 254))
   Dim backBrush2 As New SolidBrush(Color.FromArgb(198, 241, 249))
   Dim backBrush3 As New SolidBrush(Color.FromArgb(253, 192, 47))
   ' declare field representing the text of the item being drawn
   Dim itemText As String = (TryCast(sender, ListBoxControl)).GetItemText(e.Index)
   If Not (e.State And DrawItemState.Selected) = 0 Then
      e.Cache.FillRectangle(backBrush3, e.Bounds)
      ControlPaint.DrawBorder3D(e.Graphics, e.Bounds)
      e.Cache.DrawString(itemText, New Font(e.Appearance.Font.Name, e.Appearance.Font.Size, _
        FontStyle.Bold), New SolidBrush(Color.Black), e.Bounds, e.Appearance.GetStringFormat())
      e.Handled = True
      Exit Sub
   End If
   If e.Index Mod 2 = 0 Then
      e.Cache.FillRectangle(backBrush1, e.Bounds)
   Else
      e.Cache.FillRectangle(backBrush2, e.Bounds)
   End If
   e.Cache.DrawString(itemText, e.Appearance.Font, New SolidBrush(Color.Black), e.Bounds, 
     e.Appearance.GetStringFormat())
   e.Handled = True
End Sub

Related GitHub Examples

The following code snippets (auto-collected from DevExpress Examples) contain references to the DrawItem 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-implement-the-checkstyle-feature-for-checkedcomboboxedit-e4041/CS/CustomEdit/CustomCheckedComboBoxEdit.cs#L28

if (listBoxControl != null)
    listBoxControl.DrawItem -= CustomCheckedComboBoxEdit_DrawItem;
images.Dispose();

how-to-show-images-in-the-checkedcomboboxedit-edit-box-and-its-dropdown-window-e2804/CS/WindowsApplication3/CheckedImageComboBoxEdit.cs#L37

if(Properties.CanShowImageInDropDown)
    listBox.DrawItem += OnDrawItem;
return ctrl;

VB.NET

how-to-implement-the-checkstyle-feature-for-checkedcomboboxedit-e4041/VB/CustomEdit/CustomCheckedComboBoxEdit.vb#L29

If listBoxControl IsNot Nothing Then
    RemoveHandler listBoxControl.DrawItem, AddressOf CustomCheckedComboBoxEdit_DrawItem
End If

how-to-show-images-in-the-checkedcomboboxedit-edit-box-and-its-dropdown-window-e2804/VB/WindowsApplication3/CheckedImageComboBoxEdit.vb#L47

If Properties.CanShowImageInDropDown Then
    AddHandler listBox.DrawItem, AddressOf OnDrawItem
End If