BaseListBoxControl.DrawItem Event

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

Namespace: DevExpress.XtraEditors

Assembly: DevExpress.XtraEditors.v23.2.dll

NuGet Package: DevExpress.Win.Navigation

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.
Index	Gets the index of the item being painted.
Item	Gets the value of the processed item.
PaintArgs
State	Gets the state of the item being painted.

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 Handled property to true to override the default painting.

Example

The following sample code handles the BaseListBoxControl.DrawItem event to custom paint odd and even list box items. The event handler also custom paints the currently selected item.

C#

using DevExpress.XtraEditors;

private void listBoxControl1_DrawItem(object sender, DevExpress.XtraEditors.ListBoxDrawItemEventArgs e) {
    Brush evenItemBackBrush = Brushes.WhiteSmoke;
    Brush oddItemBackBrush = Brushes.LightBlue;
    Brush selectedItemBackBrush = Brushes.SteelBlue;
    string itemText = (sender as ListBoxControl).GetItemText(e.Index);
    if ((e.State & DrawItemState.Selected) != 0) {
        e.Cache.FillRectangle(selectedItemBackBrush, e.Bounds);
        using (Font f = new Font(e.Appearance.Font.Name, e.Appearance.Font.Size, FontStyle.Bold)) {
            e.Cache.DrawString(itemText, f, Brushes.White, e.Bounds, e.Appearance.GetStringFormat());
        }
        e.Handled = true;
        return;
    }
    if (e.Index % 2 == 0) {
        e.Cache.FillRectangle(evenItemBackBrush, e.Bounds);
    }
    else {
        e.Cache.FillRectangle(oddItemBackBrush, e.Bounds);
    }
    e.Cache.DrawString(itemText, e.Appearance.Font, Brushes.Black, e.Bounds, e.Appearance.GetStringFormat());
    e.Handled = true;
}

VB.NET

Private Sub ListBoxControl1_DrawItem(sender As Object, e As DevExpress.XtraEditors.ListBoxDrawItemEventArgs) Handles ListBoxControl1.DrawItem
    Dim evenItemBackBrush As Brush = Brushes.WhiteSmoke
    Dim oddItemBackBrush As Brush = Brushes.LightBlue
    Dim selectedItemBackBrush As Brush = Brushes.SteelBlue
    Dim itemText As String = (TryCast(sender, ListBoxControl)).GetItemText(e.Index)
    If (e.State And DrawItemState.Selected) <> 0 Then
        e.Cache.FillRectangle(selectedItemBackBrush, e.Bounds)
        Using f As Font = New Font(e.Appearance.Font.Name, e.Appearance.Font.Size, FontStyle.Bold)
            e.Cache.DrawString(itemText, f, Brushes.White, e.Bounds, e.Appearance.GetStringFormat())
        End Using
        e.Handled = True
        Return
    End If
    If e.Index Mod 2 = 0 Then
        e.Cache.FillRectangle(evenItemBackBrush, e.Bounds)
    Else
        e.Cache.FillRectangle(oddItemBackBrush, e.Bounds)
    End If
    e.Cache.DrawString(itemText, e.Appearance.Font, Brushes.Black, e.Bounds, e.Appearance.GetStringFormat())
    e.Handled = True
End Sub

Related GitHub Examples

The following code snippet (auto-collected from DevExpress Examples) contains a reference 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#

winforms-checked-combobox-with-images/CS/WindowsApplication3/CheckedImageComboBoxEdit.cs#L37

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

VB.NET

winforms-checked-combobox-with-images/VB/WindowsApplication3/CheckedImageComboBoxEdit.vb#L47

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